Intersection of biology and therapeutics: type 2 targeted therapeutics for adult asthma

Improvement of RSV-Induced Asthma in Mice: A Study Based on Icariin-Mediated PD-1

BACKGROUND

Infection with respiratory syncytial virus (RSV) has the potential to exacerbate asthma by causing prolonged inflammation in the airways. Mounting evidence has revealed the significant involvement of programmed cell death protein-1 (PD-1) in the development of asthma. Although icariin (IC) has shown potential in improving airway remodeling in ovalbumin (OVA)-induced asthma, its impact and underlying mechanisms in cases of asthma aggravated by RSV infection are not thoroughly understood.

OBJECTIVE

To explore the effect of IC on RSV-infected asthmatic mice and the mechanism involving PD-1.

METHODS

A model of asthmatic mice infected with RSV was developed. To evaluate the effects of IC treatment, general behavioral characterization, histopathologic analysis, bronchoalveolar lavage fluid (BALF) analysis, and enzyme-linked immunosorbent assays (ELISA) were performed to assess the frequency of sneezing and nose scratching, the content of OVA-specific IgE, oxidative stress and airway inflammation in mice. Apoptosis was also assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Finally, the expression levels of apoptosis protein, oxidative stress-related protein, and PD-1 were assessed by western blot.

RESULTS

IC significantly ameliorated the sneezing and nose-scratching frequency (p < 0.001) and decreased OVA-specific IgE levels in asthmatic mice infected with RSV (p < 0.01). IC treatment remarkably reduced the infiltration of inflammatory cells around the alveoli and lowered the overall inflammation score. It also notably decreased the levels of inflammatory cytokines interleukin-4 (IL-4), IL-13, and IL-5, and decreased the numbers of neutrophils, eosinophils, and macrophages in the bronchoalveolar lavage fluid (BALF) (p < 0.001). IC ameliorated oxidative stress in RSV-infected asthmatic mice (p < 0.001). In addition, IC reduced apoptosis while increasing PD-1 expression in asthmatic mice infected with RSV (p < 0.001). Interestingly, si-PD-1 significantly reversed IC inhibition of inflammatory cytokines and apoptosis-related proteins, and promoted PD-1 protein expression (p < 0.01). The findings suggested that IC might be effective in alleviating asthma triggered by RSV in mice by regulating the expression of PD-1.

CONCLUSION

IC ameliorated RSV-induced asthma in mice by regulating PD-1 expression, and may hold promise as a potential therapeutic agent for RSV-induced asthma in mice. These findings provide valuable insights into the possibility of using IC as a treatment option for asthma caused by RSV.

Durability of benralizumab effectiveness in severe eosinophilic asthma patients with and without chronic rhinosinusitis with nasal polyps: a post hoc analysis from the ANANKE study

Introduction

Severe eosinophilic asthma (SEA) often co-occurs with chronic rhinosinusitis with nasal polyps (CRSwNP), worsening asthma symptoms. Earlier studies have shown that benralizumab improves asthma outcomes with greater efficacy if patients present CRSwNP.

Methods

This post hoc analysis of the ANANKE study (NCT04272463) reports data on the long-term effectiveness of benralizumab between SEA patients with and without CRSwNP (N = 86 and N = 75, respectively) treated for up to 96 weeks.

Results

Before benralizumab initiation, CRSwNP patients displayed longer SEA duration, greater oral corticosteroid (OCS) use and blood eosinophil count. After 96 weeks of treatment, the annual exacerbation rate (AER) decreased in both groups, with CRSwNP patients achieving considerable reductions than No-CRSwNP patients (severe AER dropped by 100% and 95.6%, respectively). While lung function improvement was comparable at week 96, CRSwNP patients showed a faster response to benralizumab, with a rise of forced expiratory volume in 1 s (FEV1) at 16 weeks that was maintained throughout the study. Median OCS daily dose decreased to 0.0 mg in both groups at 96 weeks, but benralizumab OCS-sparing effect was faster in CRSwNP patients (median OCS dose was 0.0 mg and 2.5 mg in CRSwNP and No-CRSwNP patients respectively, at 48 weeks). Although asthma control test (ACT) median scores were comparable, greater proportions of CRSwNP patients displayed well-controlled asthma (ACT ≥ 20) than No-CRSwNP patients at all time points.

Discussion

These findings show benralizumab long-term effectiveness in SEA patients with and without CRSwNP, highlighting its superior and faster-acting benefits on asthma outcomes in presence of CRSwNP.

Fecal Microbiota Transplantation Alleviates Airway Inflammation in Asthmatic Rats by Increasing the Level of Short-Chain Fatty Acids in the Intestine

Asthma is a prevalent chronic inflammatory disorder of the respiratory tract that not only manifests with respiratory symptoms but also often involves intestinal flora disorders and gastrointestinal dysfunction. Recent studies have confirmed the close relationship between the gut and lungs, known as the "gut-lung axis" theory. Fecal microbiota transplantation (FMT), a method for restoring normal intestinal flora, has shown promise in treating common gastrointestinal diseases. The "gut-lung axis" theory suggests that FMT may have significant therapeutic potential for asthma. In this study, we established an Ovalbumin (OVA)-induced rat model of asthma to investigate the protective effect of FMT on airway inflammation and the restoration of intestinal short-chain fatty acids (SCFAs), aiming to explore its underlying mechanism. Rats in the Control group underwent fecal treatment via gavage (Control-FMT, C-FMT group), while rats in the Asthma group underwent fecal treatment via gavage after asthma induction (Asthma-FMT, A-FMT group). Following a two-week period of continuous intragastric administration, various measurements were conducted to assess pulmonary function, peripheral blood neutrophil, lymphocyte, and eosinophil content, lung tissue pathology, and collagen fiber deposition in the lungs. Additionally, neutrophil and eosinophil content in bronchoalveolar lavage fluid (BALF), expression levels of Interleukin-4 (IL-4), IL-5, IL-13, IL-17, IL-33, leukotrienes (LT), thymic stromal lymphopoietin (TSLP), prostaglandin D2 (PGD2) protein and mRNA in lung tissue, and SCFAs content in stool were evaluated. In the C-FMT group, lung function significantly improved, inflammatory cell content in peripheral blood and BALF decreased, lung tissue pathology and collagen fiber deposition significantly improved, the protein and mRNA levels of lung inflammatory factors IL-4, IL-5, IL-13, IL-17, IL-33, LT, TSLP, PGD2 were significantly decreased, and SCFAs such as acetate (C2), propionate (C3), butyrate (C4), isobutyric acid (I-C4), valeric acid (C5), and isovaleric acid (I-C5) content in stool significantly increased. However, the indexes in the A-FMT group did not show significant recovery, and the treatment effect on asthma symptoms in rats was inferior to that in the C-FMT group. Asthma induced intestinal flora disorders in rats, and FMT treatment improved the inflammatory response in asthmatic rat models and corrected their intestinal SCFAs disorders. Encouraging the recovery of intestinal SCFAs may play a significant role, and beneficial bacteria present in feces may improve asthma symptoms by promoting the remodeling of intestinal flora. This experiment provides further scientific evidence supporting the "gut-lung axis" theory.

Pulmonary-delivered Anticalin Jagged-1 antagonists reduce experimental airway mucus hyperproduction and obstruction

Mucus hypersecretion and mucus obstruction are pathogenic features in many chronic lung diseases directly linked to disease severity, exacerbation, progression, and mortality. The Jagged-1/Notch pathway is a promising therapeutic target that regulates secretory and ciliated cell trans-differentiation in the lung. However, the Notch pathway is also required in various other organs. Hence, pulmonary delivery of therapeutic agents is a promising approach to target this pathway while minimizing systemic exposure. Using Anticalin technology, Jagged-1 Anticalin binding proteins were generated and engineered to potent and selective inhalable Jagged-1 antagonists. Their therapeutic potential to reduce airway mucus hyperproduction and obstruction was investigated ex vivo and in vivo. In primary airway cell cultures grown at an air-liquid interface and stimulated with inflammatory cytokines, Jagged-1 Anticalin binding proteins reduced both mucin gene expression and mucous cell metaplasia. In vivo, prophylactic and therapeutic treatment with a pulmonary-delivered Jagged-1 Anticalin binding protein reduced mucous cell metaplasia, epithelial thickening, and airway mucus hyperproduction in IL-13 and house dust mite allergen-challenged mice, respectively. Furthermore, in a transgenic mouse model with pathophysiologic features of cystic fibrosis and chronic obstructive pulmonary disease (COPD), pulmonary-delivered Jagged-1 Anticalin binding protein reduced hallmarks of airway mucus obstruction. In all in vivo models, a reduction of mucous cells with a concomitant increase of ciliated cells was observed. Collectively, these findings support Jagged-1 antagonists' therapeutic potential for patients with muco-obstructive lung diseases and the feasibility of targeting the Jagged-1/Notch pathway by inhalation.NEW & NOTEWORTHY Airway mucus drives severity and mortality in diverse chronic lung diseases. The Jagged-1/Notch pathway controls the balance of ciliated versus mucous cells, but targeting the pathway systemically carries the risk of side effects. Here we developed novel, Anticalin-derived, pulmonary-delivered Jagged-1 antagonists, to inhibit airway mucus hyperproduction and obstruction in chronic lung diseases. Our preclinical data demonstrate the effectiveness of these antagonists in diminishing secretory cell and mucus levels and alleviating hallmarks of mucus obstruction.

Levels of total IgE versus specific IgE during childhood for defining and predicting T2-high asthma

Background

T2-high asthma is characterized by elevated blood eosinophils (b-eos), and/or fractional exhaled nitric oxide (FeNO), and/or being "allergy-driven", which is not well-defined.

Objective

To investigate the role of total and specific immunoglobulin E (tIgE/sIgE) for defining and predicting T2-high asthma in childhood as biomarkers of "allergy-driven".

Methods

We utilized data from the COPSAC2000 (n = 411) and COPSAC2010 (n = 700) mother-child cohorts with repeated measurements of tIgE, sIgE, b-eos and FeNO through childhood. We defined T2-high asthma by elevated b-eos (≥0.3 × 109/L) and/or FeNO (≥20 ppb) and analyzed association with elevated tIgE (age-specific cut-offs) and sIgE (≥0.35 kU/L) using logistic regression at ages 7/10/13/18 years. Further, we analyzed the association between elevated tIgE and sIgE at age 0-4 years and later risk of T2-high asthma using logistic regression and ROC models.

Results

Elevated tIgE was associated with risk of T2-high asthma at all time points, whereas elevated sIgE showed similar results at ages 10/13/18 years. There was no overall model fit preference for a combination of tIgE and sIgE instead of tIgE or sIgE alone using Vuong's Likelihood-Ratio-Test, Akaike or Bayesian Information Criterion. Further, elevated tIgE at age 0-4 years was associated with later risk of T2-high asthma at all time points (AUC = 0.63-0.70, sensitivity = 0.62-0.81, specificity = 0.57-0.78), whereas elevated sIgE at 0-4 years was only associated with T2-high asthma at 18 years (AUC = 0.66, sensitivity = 0.45, specificity = 0.88). There were no significant differences in AUC values between tIgE and sIgE (DeLong's test).

Conclusion

Elevated tIgE and sIgE are equally useful stand-alone biomarkers for defining and predicting risk of T2-high asthma in childhood.

Japanese Patients with Severe Asthma Identified as Responders to Omalizumab Treatment at 2 Years Based on the GETE Score Continued Treatment for an Extended Period

Purpose

Omalizumab, the anti-IgE monoclonal antibody used to treat severe asthma, reduces asthma exacerbations, hospitalizations, and corticosteroid use. Although allergic asthma is a therapeutic target of omalizumab, omalizumab is not effective in all patients with severe allergic asthma and is not always available for long-term use. We retrospectively investigated factors related to long-term (≥2 years) use of omalizumab for severe asthma.

Patients and Methods

Of the 116 patients treated with omalizumab for severe asthma at our hospital between 2009 and 2017, 82 were included in this retrospective analysis. Thirty-four were excluded because of adverse events, financial difficulties, or hospital transfers. The number of asthma exacerbations, unscheduled visits, corticosteroid doses, asthma control test scores, pulmonary function test results, and fractional exhaled nitric oxide levels were evaluated.

Results

The median age of the study population was 58 years, with 66% female and 26% taking regular oral corticosteroids. After 2 years of treatment, 52 responders were identified using the global evaluation of treatment effectiveness (GETE) score. Improvements in asthma control test scores, airflow limitation, exacerbations, and oral corticosteroid use were observed in the responders. Multivariate analysis revealed that a peripheral blood eosinophil count of ≥200 or a perennial antigen-specific IgE antibody positivity of ≥2 predicted a response at the 2-year mark. However, Kaplan-Meier analysis demonstrated that neither high eosinophil counts nor perennial antigen-specific IgE positivity influenced the prolongation of treatment beyond 2 years, and responders at 2 years underwent omalizumab treatment for a significantly longer period than non-responders (HR = 9.89, p < 0.001), with GETE at 2 years being the only predictor of long-term omalizumab use.

Conclusion

In this retrospective study the GETE after 2 years of omalizumab therapy emerged as the most meaningful predictor of the long-term effectiveness of omalizumab treatment in patients with severe asthma, highlighting the benefits of prolonged therapy in certain populations. These findings may guide future therapeutic strategies for severe asthma.

Surface-engineered mesenchymal stem cell for refractory asthma therapy: Reversing airway remodeling

In the development of asthma, subepithelial fibrosis and vascular proliferation cause airway remodeling and narrowing, leading to disease deterioration and respiratory failure. In the clinic, the treatment of asthma was aimed at reducing the frequency of acute asthma attacks through inhaled corticosteroids (ICSs). However, ICSs cannot prevent the progression into refractory asthma due to the formation of airway remodeling mainly by subepithelial fibrosis and angiogenesis surrounding the tracheal lumen. Herein, we constructed surface-engineered mesenchymal stem cells (MSCs/PVLA) via the bioconjugation of MSCs and reactive oxygen species-responsive polymeric micelles loaded with vactosertib (VST) and linifanib (LFN) for treating refractory asthma through reversing airway remodeling. MSCs/PVLA migrated to the tracheal lumen due to the inflammation tropism of MSCs, and subsequently released VST and LFN could inhibit the formation of airway remodeling by preventing subepithelial fibrosis and angiogenesis. Meanwhile, MSCs reduced inflammatory cell infiltration and cytokine secretion to regulate the pathological microenvironment. Our results suggested that MSCs/PVLA could serve as a promising candidate to prevent disease exacerbations and treat refractory asthma.

Multiomics analysis identified IL-4-induced IL1RL1high eosinophils characterized by prominent cysteinyl leukotriene metabolism

BACKGROUND

Clinical studies have demonstrated that IL-4, a type 2 cytokine, plays an important role in the pathogenesis of chronic rhinosinusitis and eosinophilic asthma. However, the direct effect of IL-4 on eosinophils remains unclear.

OBJECTIVE

We aimed to elucidate the inflammatory effects of IL-4 on the functions of human eosinophils.

METHODS

A multiomics analysis comprising transcriptomics, proteomics, lipidomics, quantitative RT-PCR, and flow cytometry was performed by using blood eosinophils from healthy subjects stimulated with IL-4, IL-5, or a combination thereof.

RESULTS

Transcriptomic and proteomic analyses revealed that both IL-4 and IL-5 upregulate the expression of γ-gultamyl transferase 5, a fatty acid-metabolizing enzyme that converts leukotriene C4 into leukotriene D4. In addition, IL-4 specifically upregulates the expression of IL-1 receptor-like 1 (IL1RL1), a receptor for IL-33 and transglutaminase-2. Additional transcriptomic analysis of cells stimulated with IL-13 revealed altered gene expression profiles, characterized by the upregulation of γ-gultamyl transferase 5, transglutaminase-2, and IL1RL1. The IL-13-induced changes were not totally different from the IL-4-induced changes. Lipidomic analysis revealed that IL-5 and IL-4 additively increased the extracellular release of leukotriene D4. In vitro experiments revealed that STAT6 and IL-4 receptor-α control the expression of these molecules in the presence of IL-4 and IL-13. Analysis of eosinophils derived from patients with allergic disorders indicated the involvement of IL-4 and IL-13 at the inflamed sites.

CONCLUSIONS

IL-4 induces the proallergic phenotype of IL1RL1high eosinophils, with prominent cysteinyl leukotriene metabolism via STAT6. These cellular changes represent potential therapeutic targets for chronic rhinosinusitis and eosinophilic asthma.

The role of DC subgroups in the pathogenesis of asthma

Dendritic cells (DCs), specialized antigen-presenting cells of the immune system, act as immunomodulators in diseases of the immune system, including asthma. The understanding of DC biology has evolved over the years to include multiple subsets of DCs with distinct functions in the initiation and maintenance of asthma. Moreover, most strategies for treating asthma with relevant therapeutic agents that target DCs have been initiated from the study of DC function. We discussed the pathogenesis of asthma (including T2-high and T2-low), the roles played by different DC subpopulations in the pathogenesis of asthma, and the therapeutic strategies centered around DCs. This study will provide a scientific theoretical basis for current asthma treatment, provide theoretical guidance and research ideas for developing and studying therapeutic drugs targeting DC, and provide more therapeutic options for the patient population with poorly controlled asthma symptoms.

Baicalin Attenuates Type 2 Immune Responses in a Mouse Allergic Asthma Model through Inhibiting the Production of Thymic Stromal Lymphopoietin

INTRODUCTION

Baicalin is a flavonoid chemical extracted and purified from the traditional Chinese medicine named Scutellaria baicalensis Georgi, which possesses broad pharmacological properties. Our work aimed to explore the protective role of baicalin in allergic asthma and its potential mechanisms on regulating type 2 immune response.

METHODS

Mice were injected intraperitoneally with ovalbumin (OVA) twice, further challenged with OVA aerosol for continuous 5 days. For baicalin group, mice were pre-administrated with baicalin. After the final challenge, the immune cells in bronchoalveolar lavage fluid (BALF) and blood were examined. The cytokines were evaluated by ELISA. Histological inspections were examined by hematoxylin and eosin staining and Periodic Acid-Schiff staining. Thymic stromal lymphopoietin (TSLP) expression in lungs were detected using immunohistochemistry and Western blotting.

RESULTS

The eosinophils infiltrating in BALF were reduced remarkably in baicalin-treated asthmatic mice. Baicalin decreased OVA-induced inflammatory cytokines and total serum immunoglobulin E secretion significantly. Moreover, baicalin alleviated the asthmatic pathological changes and substantially suppressed TSLP expression in the lung tissues.

CONCLUSION

Our study indicates that baicalin attenuates OVA-induced allergic asthma in mice effectively by suppressing type 2 immune responses, which might provide a novel insight into the anti-asthmatic activity of baicalin.

To investigate the function of age-related genes in different subtypes of asthma based on bioinformatics analysis

Asthma is a heterogeneous airway inflammatory disease that can be classified according to the inflammatory phenotype. The pathogenesis, clinical features, response to hormone therapy, and prognosis of different inflammatory phenotypes differ significantly. This condition also refers to age-related chronic ailments. Here, we intend to identify the function of aging-related genes in different inflammatory phenotypes of asthma using bioinformatic analyses. Initially, the research adopted the GSEA analysis to understand the fundamental mechanisms that govern different inflammatory phenotypes of asthma pathogenesis and use the CIBERSORT algorithm to assess the immune cell composition. The differentially expressed genes (DEGs) of eosinophilic asthma (EA), neutrophilic asthma (NA), and paucigranulocytic asthma (PGA) were identified through the limma R package. Aging-related genes, screened from multiple databases, were intersected with DEGs of asthma to obtain the asthma-aging-related DEGs. Then, the GO and KEGG pathway enrichment analyses showed that the NA- and EA-aging-related DEGs are involved in the various cytokine-mediated signaling pathways. PPI network and correlation analysis were performed to identify and evaluate the correlation of the hub genes. Further, the clinical characteristics of asthma-aging-related DEGs were explored through ROC analysis. 3 and 12 aging-related DEGs in EA and NA patients show high diagnostic accuracy, respectively (AUC >0.7). This study provided valuable insights into aging-related gene therapy for phenotype-specific asthma. Moreover, the study suggests that effective interventions against asthma may operate by disrupting the detrimental cycle of "aging induces metabolic diseases, which exacerbate aging".

From mesenchymal stem cells to their extracellular vesicles: Progress and prospects for asthma therapy

Asthma is a widespread public health concern, with an increasing incidence. Despite the implementation of current treatment strategies, asthma control, particularly for severe cases, remains suboptimal. Recent research has revealed the encouraging prospects of extracellular vesicles (EVs) secreted by mesenchymal stem cells (MSCs) as a viable therapeutic option for alleviating asthma symptoms. Therefore, the present review aims to provide an overview of the current progress and the therapeutic mechanisms of using MSC-derived EVs (MSC-EVs) for asthma treatment. Additionally, different administration approaches for EVs and their impacts on biodistribution and the curative outcomes of EVs are summarized. Notably, the potential benefits of nebulized inhalation of MSC-EVs are addressed. Also, the possibilities and challenges of using MSC-EVs for asthma treatment in clinics are highlighted. Overall, this review is intended to give new insight into the utilization of MSC-EVs as a potential biological drug for asthma treatment.

[Severe asthma: Pathophysiology, diagnosis, and treatment]

Severe asthma is an entity with a complex diagnosis, requiring an adequate differential diagnosis and identification of endotypes for a correct approach and therapeutic process. In the present review, we show a synthesis of the current literature on the diagnosis, pathophysiology, and management of severe asthma, having critically analyzed the evidence in search engines such as Medline, Scopus, and Embase.

A novel quinoline with airway relaxant effects and anti-inflammatory properties

BACKGROUND

In chronic pulmonary diseases characterized by inflammation and airway obstruction, such as asthma and COPD, there are unmet needs for improved treatment. Quinolines is a group of small heterocyclic compounds that have a broad range of pharmacological properties. Here, we investigated the airway relaxant and anti-inflammatory properties of a novel quinoline (RCD405).

METHODS

The airway relaxant effect of RCD405 was examined in isolated airways from humans, dogs, rats and mice. Murine models of ovalbumin (OVA)-induced allergic asthma and LPS-induced airway inflammation were used to study the effects in vivo. RCD405 (10 mg/kg) or, for comparisons in selected studies, budesonide (3 mg/kg), were administered intratracheally 1 h prior to each challenge. Airway responsiveness was determined using methacholine provocation. Immune cell recruitment to bronchi was measured using flow cytometry and histological analyses were applied to investigate cell influx and goblet cell hyperplasia of the airways. Furthermore, production of cytokines and chemokines was measured using a multiplex immunoassay. The expression levels of asthma-related genes in murine lung tissue were determined by PCR. The involvement of NF-κB and metabolic activity was measured in the human monocytic cell line THP-1.

RESULTS

RCD405 demonstrated a relaxant effect on carbachol precontracted airways in all four species investigated (potency ranking: human = rat > dog = mouse). The OVA-specific IgE and airway hyperresponsiveness (AHR) were significantly reduced by intratracheal treatment with RCD405, while no significant changes were observed for budesonide. In addition, administration of RCD405 to mice significantly decreased the expression of proinflammatory cytokines and chemokines as well as recruitment of immune cells to the lungs in both OVA- and LPS-induced airway inflammation, with a similar effect as for budesonide (in the OVA-model). However, the effect on gene expression of Il-4, IL-5 and Il-13 was more pronounced for RCD405 as compared to budesonide. Finally, in vitro, RCD405 reduced the LPS-induced NF-κB activation and by itself reduced cellular metabolism.

CONCLUSIONS

RCD405 has airway relaxant effects, and it reduces AHR as well as airway inflammation in the models used, suggesting that it could be a clinically relevant compound to treat inflammatory airway diseases. Possible targets of this compound are complexes of mitochondrial oxidative phosphorylation, resulting in decreased metabolic activity of targeted cells as well as through pathways associated to NF-κB. However, further studies are needed to elucidate the mode of action.

A deep insight into ferroptosis in lung disease: facts and perspectives

In the last decade, ferroptosis has received much attention from the scientific research community. It differs from other modes of cell death at the morphological, biochemical, and genetic levels. Ferroptosis is mainly characterized by non-apoptotic iron-dependent cell death caused by iron-dependent lipid peroxide excess and is accompanied by abnormal iron metabolism and oxidative stress. In recent years, more and more studies have shown that ferroptosis is closely related to the occurrence and development of lung diseases. COPD, asthma, lung injury, lung fibrosis, lung cancer, lung infection and other respiratory diseases have become the third most common chronic diseases worldwide, bringing serious economic and psychological burden to people around the world. However, the exact mechanism by which ferroptosis is involved in the development and progression of lung diseases has not been fully revealed. In this manuscript, we describe the mechanism of ferroptosis, targeting of ferroptosis related signaling pathways and proteins, summarize the relationship between ferroptosis and respiratory diseases, and explore the intervention and targeted therapy of ferroptosis for respiratory diseases.

The role of hormones in ILC2-driven allergic airway inflammation

Group 2 innate lymphoid cells (ILC2s) are a type of innate immune cells that produce a large amount of IL-5 and IL-13 and two cytokines that are crucial for various processes such as allergic airway inflammation, tissue repair and tissue homeostasis. It is known that damaged epithelial-derived alarmins, such as IL-33, IL-25 and thymic stromal lymphopoietin (TSLP), are the predominant ILC2 activators that mediate the production of type 2 cytokines. In recent years, abundant studies have found that many factors can regulate ILC2 development and function. Hormones synthesized by the body's endocrine glands or cells play an important role in immune response. Notably, ILC2s express hormone receptors and their proliferation and function can be modulated by multiple hormones during allergic airway inflammation. Here, we summarize the effects of multiple hormones on ILC2-driven allergic airway inflammation and discuss the underlying mechanisms and potential therapeutic significance.

Mild asthma: Conundrums, complexities and the need to customize care

Mild and moderate asthma cover a wide range of asthma presentations, phenotypes and symptom burden, and account for the majority of people with asthma worldwide. Mild asthma has been difficult to define because of its heterogeneity and wide spectrum of impact and outcomes, including being associated with severe exacerbations. Assessment of mild-moderate asthma is best made by combining asthma symptom control and exacerbation risk as the principle means by which to determine treatment needs. Incontrovertible evidence and guidelines support treatment initiation with anti-inflammatory medication, completely avoiding reliever-only treatment of mild asthma. Shared decision making with patients and a treatable traits approach will ensure that a holistic approach is taken to maximize patient outcomes. Most importantly, mild asthma should be regarded as a reversible, potentially curable condition, remaining in long-term remission through minimizing triggers and optimizing care.

Short-term effects of air pollutants on hospital admissions for asthma among older adults: a multi-city time series study in Southwest, China

Background

This study aimed to explore the relationship between air pollution and hospital admissions for asthma in older adults, and to further assess the health and economic burden of asthma admissions attributable to air pollution.

Methods

We collected information on asthma cases in people over 65 years of age from nine cities in Sichuan province, as well as air pollution and meteorological data. The relationship between short-term air pollutant exposure and daily asthma hospitalizations was analyzed using the generalized additive model (GAM), and stratified by gender, age, and season. In addition, we assessed the economic burden of hospitalization for air pollution-related asthma in older adults using the cost of disease approach.

Results

The single pollutant model showed that every 1 mg/m3 increase in CO was linked with an increase in daily hospitalizations for older adults with asthma, with relative risk values of 1.327 (95% CI: 1.116-1.577) at lag7. Each 10 μg/m3 increase in NO2, O3, PM10, PM2.5 and SO2, on asthma hospitalization, with relative risk values of 1.044 (95% CI: 1.011-1.078), 1.018 (95% CI: 1.002-1.034), 1.013 (95% CI: 1.004-1.022), 1.015 (95% CI: 1.003-1.028) and 1.13 (95% CI: 1.041-1.227), respectively. Stratified analysis shows that stronger associations between air pollution and asthma HAs among older adult in females, those aged 65-69 years, and in the warm season, although all of the differences between subgroups did not reach statistical significance. During the study period, the number of asthma hospitalizations attributable to PM2.5, PM10, and NO2 pollution was 764, 581 and 95, respectively, which resulted in a total economic cost of 6.222 million CNY, 4.73 million CNY and 0.776 million CNY, respectively.

Conclusion

This study suggests that short-term exposure to air pollutants is positively associated with an increase in numbers of asthma of people over 65 years of age in Sichuan province, and short-term exposure to excessive PM and NO2 brings health and economic burden to individuals and society.

The Saudi initiative for asthma - 2024 update: Guidelines for the diagnosis and management of asthma in adults and children

The Saudi Initiative for Asthma 2024 (SINA-2024) is the sixth version of asthma guidelines for the diagnosis and management of asthma for adults and children that was developed by the SINA group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up-to-date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA Panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is aligned for age groups: adults, adolescents, children aged 5-12 years, and children aged <5 years. SINA guidelines have focused more on personalized approaches reflecting a better understanding of disease heterogeneity with the integration of recommendations related to biologic agents, evidence-based updates on treatment, and the role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and the current situation at national and regional levels. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

HMGB1 inhibition reduces TDI-induced occupational asthma through ROS/AMPK/autophagy pathway

Exposure to toluene diisocyanate (TDI) can cause pulmonary diseases such as asthma. Inhibition of high mobility group box 1 protein (HMGB1) has been found to be protective against the toxic effects of TDI on human bronchial epithelial (HBE) cells. Here, we evaluated the in vivo positive roles of HMGB1 in the TDI-caused asthma mice and explored its underlying mechanisms in HBE cells. We found that suppression of HMGB1 obviously alleviated airway inflammation, airway hyperresponsiveness, and airway remodeling in the lung tissue of the asthma mice. The in vitro results showed that inhibition of HMGB1 ameliorated TDI-induced reactive oxygen species (ROS) release, inflammatory response, and activation of autophagy in HBE cells. At the molecular level, inhibition of HMGB1 decreased the expressions of HMGB1, Toll-like receptor 4, Vimentin and matrix metalloproteinase-9 proteins, activated NF-κB and NOD-like receptor protein 3 (NLRP3) inflammasome, and increased E-cadherin expression. Importantly, activation of autophagy could lead to the overactivation of NLRP3 inflammasome in TDI-induced asthma. These results suggest that inhibition of HMGB1 can alleviate TDI-induced asthma through ROS/AMPK/autophagy pathways, which may provide valuable evidence for the pathogenesis and therapeutic targets of TDI-induced asthma.

Urine 2-hydroxyphenanthrene is associated with current asthma: evidence from NHANES 2007-2012

OBJECTIVE

The current study aims to explore the effects of nine urine monohydroxy PAH metabolites (OHPAH) including 1-hydroxynaphthalene (1-OHNAP), 2-hydroxynaphthalene (2-OHNAP), 3-hydroxyfluorene (3-OHFLU), 9-hydroxyfluorene (9-OHFLU), 1-hydroxyphenanthrene (1-OHPHE), 2-hydroxyphenanthrene (2-OHPHE), 3-hydroxyphenanthrene (3-OHPHE), and 1-hydroxypyrene (1-OHPYR) on current asthma in people in the United States using a variety of statistical techniques.

METHODS

A cross-sectional examination of a subsample of 3804 adults aged ≥20 from the National Health and Nutrition Examination Survey (NHANES) was conducted between 2007 and 2012. To investigate the relationship between urine OHPAHs levels and current asthma, multivariate logistic regression, Bayesian kernel machine regression (BKMR), and quantile g-computation (qgcomp) were utilized.

RESULTS

In the multivariate logistic regression model, after controlling for confounders, urine 2-OHPHE was associated with current asthma in both male (AOR = 7.17, 95% CI: 1.28-40.08) and female (AOR = 2.91, 95% CI: 1.06-8.01) smokers. In the qgcomp analysis, 2-OHPHE (39.5%), 1-OHNAP (33.1%), and 2-OHNAP (22.5%) were the major positive contributors to the risk of current asthma (OR = 2.29, 95% CI: 0.99, 5.25), and in female smokers, 9-OHFLU (25.8%), 2-OHFLU (21.5%), and 2-OHPHE (15.1%) were the major positive contributors (OR = 2.19, 95% CI: 1.06, 4.47). The results of the BKMR model basically agreed with qgcomp analysis.

CONCLUSION

Our results demonstrate a strong association of urine 2-OHPHE with current asthma, and further longitudinal studies are needed to understand the precise relationship between PAH exposure and current asthma risk.

Identification of cough-variant asthma phenotypes based on clinical and pathophysiologic data

BACKGROUND

Cough-variant asthma (CVA) may respond differently to antiasthmatic treatment. There are limited data on the heterogeneity of CVA.

OBJECTIVE

We aimed to classify patients with CVA using cluster analysis based on clinicophysiologic parameters and to unveil the underlying molecular pathways of these phenotypes with transcriptomic data of sputum cells.

METHODS

We applied k-mean clustering to 342 newly physician-diagnosed patients with CVA from a prospective multicenter observational cohort using 10 prespecified baseline clinical and pathophysiologic variables. The clusters were compared according to clinical features, treatment response, and sputum transcriptomic data.

RESULTS

Three stable CVA clusters were identified. Cluster 1 (n = 176) was characterized by female predominance, late onset, normal lung function, and a low proportion of complete resolution of cough (60.8%) after antiasthmatic treatment. Patients in cluster 2 (n = 105) presented with young, nocturnal cough, atopy, high type 2 inflammation, and a high proportion of complete resolution of cough (73.3%) with a highly upregulated coexpression gene network that related to type 2 immunity. Patients in cluster 3 (n = 61) had high body mass index, long disease duration, family history of asthma, low lung function, and low proportion of complete resolution of cough (54.1%). TH17 immunity and type 2 immunity coexpression gene networks were both upregulated in clusters 1 and 3.

CONCLUSION

Three clusters of CVA were identified with different clinical, pathophysiologic, and transcriptomic features and responses to antiasthmatics treatment, which may improve our understanding of pathogenesis and help clinicians develop individualized cough treatment in asthma.

Characterization and Factors Associated with Poor Asthma Control in Adults with Severe Eosinophilic Asthma

A study was conducted in 98 adult patients diagnosed with severe eosinophilic asthma (73.5% women, mean age 47.2 years) and followed prospectively for 1 year. The aim of the study was to characterize this population and to identify factors associated with poor prognosis at 1 year of follow-up. At the initial visit, uncontrolled severe asthma was diagnosed in 87.7% of patients. Allergic sensitization was observed in 81.7% (polysensitization in 17.3%), with clinically significant allergic asthma in 45%. The mean percentage of sputum eosinophils was 4.7% (standard deviation(SD) 6.3%) and the mean (SD) blood eosinophil count 467 (225) cells/µL. Almost half of the patients (48.3%) had sputum eosinophilia (>3% eosinophils). Sputum eosinophils correlated significantly with peripheral eosinophilia (p = 0.004) and, to a lesser extent, with fractional exhaled nitric oxide (FeNO) (p = 0.04). After 1 year, 48 patients (49%) had uncontrolled asthma in all visits, and 50 (51%) had controlled asthma in some visits. Airway obstruction (FEV₁ < 80% predicted) was the main reason for uncontrolled asthma. In the multivariate analysis, an obstructive pattern (odds ratio (OR) 7.45, 95% confidence interval (CI) 2.41-23.03, p < 0.0001) and the patient's age (OR 1.045, 95% CI 1.005-1.086, p = 0.026) were independent predictors of poor asthma control. In adult-onset and long-standing asthma, serum interleukin (IL) IL-17 was higher in the uncontrolled asthma group. This study contributes to characterizing patients with severe eosinophilic asthma in real-world clinical practice.

Eosinophils as potential biomarkers in respiratory viral infections

Eosinophils are bone marrow-derived granulocytes that, under homeostatic conditions, account for as much as 1-3% of peripheral blood leukocytes. During inflammation, eosinophils can rapidly expand and infiltrate inflamed tissues, guided by cytokines and alarmins (such as IL-33), adhesion molecules and chemokines. Eosinophils play a prominent role in allergic asthma and parasitic infections. Nonetheless, they participate in the immune response against respiratory viruses such as respiratory syncytial virus and influenza. Notably, respiratory viruses are associated with asthma exacerbation. Eosinophils release several molecules endowed with antiviral activity, including cationic proteins, RNases and reactive oxygen and nitrogen species. On the other hand, eosinophils release several cytokines involved in homeostasis maintenance and Th2-related inflammation. In the context of SARS-CoV-2 infection, emerging evidence indicates that eosinophils can represent possible blood-based biomarkers for diagnosis, prognosis, and severity prediction of disease. In particular, eosinopenia seems to be an indicator of severity among patients with COVID-19, whereas an increased eosinophil count is associated with a better prognosis, including a lower incidence of complications and mortality. In the present review, we provide an overview of the role and plasticity of eosinophils focusing on various respiratory viral infections and in the context of viral and allergic disease comorbidities. We will discuss the potential utility of eosinophils as prognostic/predictive immune biomarkers in emerging respiratory viral diseases, particularly COVID-19. Finally, we will revisit some of the relevant methods and tools that have contributed to the advances in the dissection of various eosinophil subsets in different pathological settings for future biomarker definition.

Programmed Cell Death in Asthma: Apoptosis, Autophagy, Pyroptosis, Ferroptosis, and Necroptosis

Bronchial asthma is a complex heterogeneous airway disease, which has emerged as a global health issue. A comprehensive understanding of the different molecular mechanisms of bronchial asthma may be an efficient means to improve its clinical efficacy in the future. Increasing research evidence indicates that some types of programmed cell death (PCD), including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis, contributed to asthma pathogenesis, and may become new targets for future asthma treatment. This review briefly discusses the molecular mechanism and signaling pathway of these forms of PCD focuses on summarizing their roles in the pathogenesis and treatment strategies of asthma and offers some efficient means to improve clinical efficacy of therapeutics for asthma in the near future.

Exercise Rehabilitation and Chronic Respiratory Diseases: Effects, Mechanisms, and Therapeutic Benefits

Chronic respiratory diseases (CRD), is a group of disorders, primarily chronic obstructive pulmonary disease and asthma, which are characterized by high prevalence and disability, recurrent acute exacerbations, and multiple comorbidities, resulting in exercise limitations and reduced health-related quality of life. Exercise training, an important tool in pulmonary rehabilitation, reduces adverse symptoms in patients by relieving respiratory limitations, increasing gas exchange, increasing central and peripheral hemodynamic forces, and enhancing skeletal muscle function. Aerobic, resistance, and high-intensity intermittent exercises, and other emerging forms such as aquatic exercise and Tai Chi effectively improve exercise capacity, physical fitness, and pulmonary function in patients with CRD. The underlying mechanisms include enhancement of the body's immune response, better control of the inflammatory response, and acceleration of the interaction between the vagus and sympathetic nerves to improve gas exchange. Here, we reviewed the new evidence of benefits and mechanisms of exercise intervention in the pulmonary rehabilitation of patients with chronic obstructive pulmonary disease, bronchial asthma, bronchiectasis, interstitial lung disease, and lung cancer.

Inhibition of γ-glutamyl transferase suppresses airway hyperresponsiveness and airway inflammation in a mouse model of steroid resistant asthma exacerbation

Introduction

Despite recent advances, there are limited treatments available for acute asthma exacerbations. Here, we investigated the therapeutic potential of GGsTop, a γ-glutamyl transferase inhibitor, on the disease with a murine model of asthma exacerbation.

Methods

GGsTop was administered to mice that received lipopolysaccharide (LPS) and ovalbumin (OVA) challenges. Airway hyperresponsiveness (AHR), lung histology, mucus hypersecretion, and collagen deposition were analyzed to evaluate the hallmark features of asthma exacerbation. The level of proinflammatory cytokines and glutathione were determined with/without GGsTop. The transcription profiles were also examined.

Results

GGsTop attenuates hallmark features of the disease with a murine model of LPS and OVA driven asthma exacerbation. Airway hyperresponsiveness (AHR), mucus hypersecretion, collagen deposition, and expression of inflammatory cytokines were dramatically inhibited by GGsTop treatment. Additionally, GGsTop restored the level of glutathione. Using RNA-sequencing and pathway analysis, we demonstrated that the activation of LPS/NFκB signaling pathway in airway was downregulated by GGsTop. Interestingly, further analysis revealed that GGsTop significantly inhibited not only IFNγ responses but also the expression of glucocorticoid-associated molecules, implicating that GGsTop profoundly attenuates inflammatory pathways.

Conclusions

Our study suggests that GGsTop is a viable treatment for asthma exacerbation by broadly inhibiting the activation of multiple inflammatory pathways.

Blood Basophils Relevance in Chronic Rhinosinusitis with Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by eosinophilic asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and intolerance to cyclooxygenase-1 inhibitors. Interest is emerging in studying the role of circulating inflammatory cells in CRSwNP pathogenesis and its course, as well as their potential use for a patient-tailored approach. By releasing IL-4, basophils play a crucial role in activating the Th2-mediated response. The main aim of this study was to, first, investigate the level of the pre-operative blood basophils' values, blood basophil/lymphocyte ratio (bBLR) and blood eosinophil-to-basophil ratio (bEBR) as predictors of recurrent polyps after endoscopic sinus surgery (ESS) in AERD patients. The secondary aim was to compare the blood basophil-related variables of the AERD series (study group) with those of a control group of 95 consecutive cases of histologically non-eosinophilic CRSwNP. The AERD group showed a higher recurrence rate than the control group (p < 0.0001). The pre-operative blood basophil count and pre-operative bEBR were higher in AERD patients than in the control group (p = 0.0364 and p = 0.0006, respectively). The results of this study support the hypothesis that polyps removal may contribute to reducing the inflammation and activation of basophils.

Systems Genomics Reveals microRNA Regulation of ICS Response in Childhood Asthma

BACKGROUND

Asthmatic patients' responses to inhaled corticosteroids (ICS) are variable and difficult to quantify. We have previously defined a Cross-sectional Asthma STEroid Response (CASTER) measure of ICS response. MicroRNAs (miRNAs) have shown strong effects on asthma and inflammatory processes.

OBJECTIVE

The purpose of this study was to identify key associations between circulating miRNAs and ICS response in childhood asthma.

METHODS

Small RNA sequencing in peripheral blood serum from 580 children with asthma on ICS treatment from The Genetics of Asthma in Costa Rica Study (GACRS) was used to identify miRNAs associated with ICS response using generalized linear models. Replication was conducted in children on ICS from the Childhood Asthma Management Program (CAMP) cohort. The association between replicated miRNAs and the transcriptome of lymphoblastoid cell lines in response to a glucocorticoid was assessed.

RESULTS

The association study on the GACRS cohort identified 36 miRNAs associated with ICS response at 10% false discovery rate (FDR), three of which (miR-28-5p, miR-339-3p, and miR-432-5p) were in the same direction of effect and significant in the CAMP replication cohort. In addition, in vitro steroid response lymphoblastoid gene expression analysis revealed 22 dexamethasone responsive genes were significantly associated with three replicated miRNAs. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) revealed a significant association between miR-339-3p and two modules (black and magenta) of genes associated with immune response and inflammation pathways.

CONCLUSION

This study highlighted significant association between circulating miRNAs miR-28-5p, miR-339-3p, and miR-432-5p and ICS response. miR-339-3p may be involved in immune dysregulation, which leads to a poor response to ICS treatment.

The Functional Role of Group 2 Innate Lymphoid Cells in Asthma

Asthma is a heterogeneous disease characterized by chronic airway inflammation. Group 2 innate lymphoid cells (ILC2) play an important role in the pathogenesis of asthma. ILC2s lack antigen-specific receptors and respond to epithelial-derived cytokines, leading to the induction of airway eosinophilic inflammation in an antigen-independent manner. Additionally, ILC2s might be involved in the mechanism of steroid resistance. Numerous studies in both mice and humans have shown that ILC2s induce airway inflammation through inflammatory signals, including cytokines and other mediators derived from immune or non-immune cells. ILC2s and T helper type 2 (Th2) cells collaborate through direct and indirect interactions to organize type 2 immune responses. Interestingly, the frequencies or numbers of ILC2 are increased in the blood and bronchoalveolar lavage fluid of asthma patients, and the numbers of ILC2s in the blood and sputum of severe asthmatics are significantly larger than those of mild asthmatics. These findings may contribute to the regulation of the immune response in asthma. This review article highlights our current understanding of the functional role of ILC2s in asthma.

Cimifugin suppresses type 2 airway inflammation by binding to SPR and regulating its protein expression in a non-enzymatic manner

BACKGROUND

Cimifugin is one of the main bioactive components of Yu-Ping-Feng-San, a well-known traditional Chinese medicine, which can effectively relieve Allergic asthma (AA) and atopic dermatitis and reduce recurrence in clinic. However, the underlying mechanism of cimifugin on AA is still unknown.

PURPOSE

In the present study, we aimed to investigate the effect and mechanism of cimifugin on AA.

STUDY DESIGN

In vivo and in vitro experimental studies were performed.

METHODS

The effect of cimifugin on AA was demonstrated in vivo and in vitro. Sepiapterin reductase (SPR) was predicted as the most potent target of cimifugin in treating AA by reverse docking. Molecular docking and microscale thermophoresis (MST) were used to analyze the direct binding between cimifugin and SPR. Overexpression and interference of SPR were performed to verify whether targeting SPR is a key step of cimifugin in the treatment of AA. QM385, an inhibitor of SPR, was administrated in vivo and in vitro to evaluate the role of SPR in AA. Further, HPLC and cell-free direct hSPR enzyme activity assay were performed to research whether cimifugin regulated SPR by influencing the enzyme activity. Simultaneously, the inhibitors of protein degradation were used in vitro to explore the mechanism of cimifugin on SPR.

RESULTS

We found cimifugin effectively alleviated AA by reducing airway hyperresponsiveness, inhibiting type 2 cytokines-mediated airway inflammation, and restoring the expression of epithelial barrier proteins. Molecular docking predicted the direct binding ability of cimifugin to SPR, which was further verified by MST. Notably, the therapeutic effect of cimifugin on AA was dampened with SPR interfering, in contrast, the phenotypic features of AA were significantly alleviated with QM385 application both in vivo and in vitro. Interestingly, cimifugin showed no effect on the enzyme activity of SPR, as the level of its substrate sepiapterin was not affected with cimifugin treatment by cell-free enzyme activity assay. Furthermore, we found cimifugin could reduce SPR protein expression without affecting its mRNA expression probably through autophagosome pathway.

CONCLUSIONS

To our knowledge, we're reporting for the first time that cimifugin can suppresses type 2 airway inflammation to alleviate AA by directly binding to SPR and regulating its protein expression in a non-enzymatic manner.

Interleukin-4 as a therapeutic target

Interleukin-4 (IL-4) is a pleiotropic cytokine mainly known for its role in type 2 immunity. Therapies antagonizing or blocking IL-4 activity have been developed to counteract diseases such as atopic dermatitis and asthma. In contrast, other disorders experimentally benefit from IL-4-related effects and IL-4 recently demonstrated beneficial activity in experimental stroke, spinal cord injury and the animal model of multiple sclerosis. To exploit IL-4-related activity for therapeutic concepts, current experimental efforts include modifying the pathway without inducing type 2 immune response and targeting of the cytokine to specific tissues. Here, we review different activities of IL-4 as well as therapeutic strategies.

Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis

BACKGROUND

Obesity leads to an increase in the incidence and severity of asthma. Adipokines, such as leptin, secreted by adipocytes induce systemic inflammation, causing airway inflammation. We previously reported that leptin activates both inflammatory and structural cells, including lung fibroblasts. However, little is known about the differential leptin expression and responsiveness to leptin in asthmatic individuals and healthy controls (HC). In this study, we investigated the expression and origin of leptin in asthmatic airways. We also compared the effect of leptin on asthmatic and HC fibroblasts.

METHODS

Lung specimens from asthmatic and non-asthmatic patients were analyzed by immunohistochemical staining using anti-leptin and anti-CD163 antibodies. Leptin mRNA and protein levels in human monocytes were detected by real-time PCR and western blotting and ELISA, respectively. We used flow cytometry to analyze asthmatic and HC lung fibroblasts for leptin receptor (Ob-R) expression. Further, we determined cytokine levels using cytometric bead array and ELISA and intracellular phosphorylation of specific signaling molecules using western blotting.

RESULTS

Asthma specimens displayed accumulation of leptin-positive inflammatory cells, which were also positive for CD163, a high-affinity scavenger receptor expressed by monocytes and macrophages. Leptin expression was observed at both transcript and protein levels in human blood-derived monocytes. No significant differences were observed between asthmatic and HC lung fibroblasts in Ob-R expression, cytokine production, and intracellular phosphorylation of p38 mitogen-activated protein kinase.

CONCLUSIONS

Our findings reveal similar responsiveness of control and asthmatic fibroblasts to leptin. However, the accumulation of inflammatory leptin-producing monocytes in the airway may contribute to the pathogenesis of asthma.

Dachengqi Decoction alleviates intestinal inflammation in ovalbumin-induced asthma by reducing group 2 innate lymphoid cells in a microbiota-dependent manner

Background and aim

Dachengqi Decoction (DCQD) as a classic traditional Chinese medicine has been reported to be effective in treating asthma, but its mechanism remains unknown. This study aimed to reveal the mechanisms of DCQD on the intestinal complications of asthma mediated by group 2 innate lymphoid cells (ILC2) and intestinal microbiota.

Experimental procedure

Ovalbumin (OVA) was used to construct asthmatic murine models. IgE, cytokines (e.g., IL-4, IL-5), fecal water content, colonic length, histopathologic appearance, and gut microbiota were evaluated in asthmatic mice treated with DCQD. Finally, we administered DCQD to antibiotic-treated asthmatic mice to measure the ILC2 in the small intestine and colon.

Results and conclusion

DCQD decreased pulmonary IgE, IL-4, and IL-5 levels in asthmatic mice. The fecal water content, the colonic length weight loss, and the epithelial damage of jejunum, ileum, and colon of asthmatic mice were ameliorated by DCQD. Meanwhile, DCQD greatly improved intestinal dysbiosis by enriching Allobaculum, Romboutsia and Turicibacter in the whole intestine, and Lactobacillus gasseri only in the colon. However, DCQD caused less abundant Faecalibaculum and Lactobacillus vaginalis in the small intestine of asthmatic mice. A higher ILC2 proportion in different gut segments of asthmatic mice was reversed by DCQD. Finally, significant correlations appeared between DCQD-mediated specific bacteria and cytokines (e.g., IL-4, IL-5) or ILC2. These findings indicate that DCQD alleviated the concurrent intestinal inflammation in OVA-induced asthma by decreasing the excessive accumulation of intestinal ILC2 in a microbiota-dependent manner across different gut locations.

Pharmacological OGG1 inhibition decreases murine allergic airway inflammation

Background and aim: Allergic asthma is a complex inflammatory disease involving type 2 innate lymphoid cells, type 2 T helper cells, macrophages, and eosinophils. The disease is characterized by wheezing, dyspnea, coughing, chest tightness and variable airflow limitation for which there is no cure and is symptomatically treated with inhaled corticosteroids and β2-agonists. Molecular mechanisms underlying its complex pathogenesis are not fully understood. However, 8-oxoguanine DNA glycosylase-1 (OGG1), a DNA repair protein may play a central role, as OGG1 deficiency decreases both innate and allergic inflammation.

Methods: Using a murine ovalbumin (OVA) model of allergic airway inflammation we assessed the utility of an inhibitor of OGG1 (TH5487) in this disease context. Cytokines and chemokines, promoting immune cell recruitment were measured using a 23-multiplex assay and Western blotting. Additionally, immune cell recruitment to bronchi was measured using flow cytometry. Histological analyses and immunofluorescent staining were used to confirm immune cell influx and goblet cell hyperplasia of the airways. A PCR array was used to assess asthma-related genes in murine lung tissue following TH5487 treatment. Finally, airway hyperresponsiveness was determined using in vivo lung function measurement.

Results: In this study, administration of TH5487 to mice with OVA-induced allergic airway inflammation significantly decreased goblet cell hyperplasia and mucus production. TH5487 treatment also decreased levels of activated NF-κB and expression of proinflammatory cytokines and chemokines resulting in significantly lower recruitment of eosinophils and other immune cells to the lungs. Gene expression profiling of asthma and allergy-related proteins after TH5487 treatment revealed differences in several important regulators, including down regulation of Tnfrsf4, Arg1, Ccl12 and Ccl11, and upregulation of the negative regulator of type 2 inflammation, Bcl6. Furthermore, the gene Clca1 was upregulated following TH5487 treatment, which should be explored further due to its ambiguous role in allergic asthma. In addition, the OVA-induced airway hyperresponsiveness was significantly reduced by TH5487 treatment.

Conclusion: Taken together, the data presented in this study suggest OGG1 as a clinically relevant pharmacological target for the treatment of allergic inflammation.

Biologics for chronic severe asthma: a network meta‐analysis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To evaluate the benefits and harms of biological agents targeting type‐2 inflammation (benralizumab, dupilumab, mepolizumab, omalizumab, reslizumab, tezepelumab) in people with severe asthma, with a network meta‐analysis and to rank agents by effectiveness.

Conciliatory Anti-Allergic Decoction Attenuates Pyroptosis in RSV-Infected Asthmatic Mice and Lipopolysaccharide (LPS)-Induced 16HBE Cells by Inhibiting TLR3/NLRP3/NF-κB/IRF3 Signaling Pathway

Respiratory syncytial virus (RSV) infection can deteriorate asthma by inducing persistent airway inflammation. Increasing evidence elucidated that pyroptosis plays a pivotal role in asthma. Conciliatory anti-allergic decoction (CAD) exhibits an anti-inflammatory effect in ovalbumin (OVA)-induced asthma; however, the effects and mechanisms of CAD in RSV-infected asthmatic mice have not yet been elucidated. The RSV-infected asthmatic mice model and lipopolysaccharide (LPS)-induced 16HBE cell pyroptosis model were established, respectively. Pulmonary function, ELISA, and histopathologic analysis were performed to assess the airway inflammation and remodeling in mice with CAD treatment. Furthermore, ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) was conducted to identify the chemical compounds of high-dose CAD (30 g/kg). Cell viability and apoptosis of 16HBE cells were assessed by CCK-8 and flow cytometry assays, respectively. Finally, the expression levels of apoptosis-, pyroptosis-, and TLR3/NLRP3/NF-κB/IRF3 signaling-related genes were measured with qRT-PCR or western blotting, respectively. Pulmonary function tests showed that CAD significantly ameliorated respiratory dysfunction, airway hyperresponsiveness, inflammation cell recruitment in BALF, pulmonary inflammation, collagen deposition, and cell death in lung tissues. CAD significantly decreased the content of TNF-α, IL-13, IL-4, IL-1β and IL-5 in the bronchoalveolar lavage fluid (BALF), IL-17, IL-6, and OVA-specific IgE in serum and increased serum IFN-γ in asthma mice. The results of UPLC-Q-TOF/MS showed that high-dose CAD had 88 kinds of chemical components. In vitro, CAD-contained serum significantly suppressed LPS-induced 16HBE cell apoptosis. Additionally, CAD and CAD-contained serum attenuated the up-regulated expressions of Bax, Cleaved caspase-3, NLRP3, ASC, Cleaved caspase-1, GSDMD-N, IL-18, IL-1β, TLR3, p-P65, p-IκBα, and IRF3 but increased Bcl-1 and GSDMD levels in the asthma mice and LPS-induced 16HBE cells, respectively. These results illustrated that CAD may have a potential role in improving airway inflammation and pyroptosis through inhibition of the TLR3/NLRP3/NF-κB/IRF3 signaling pathway.

Inhaled delivery of recombinant interferon-lambda restores allergic inflammation after development of asthma by controlling Th2- and Th17-cell-mediated immune responses

Remarkable progress has recently been achieved to identify the biological function and potential value of novel therapeutic targets for the effective control of allergic asthma. Interferon (IFN)-λ has been suggested to restrict chronic inflammation in the lungs of asthmatic mice and we sought to determine the contribution of IFN-λ as an asthma therapeutic. We show that inhaled IFN-λ can restrict Th2 and Th17 inflammation in the lungs of asthmatic mice, accompanied with alteration of IL-10 secretion. BALB/C mice were used for an asthmatic mouse model with OVA. Recombinant IFN-λs (IFN-λ₂: 2 μg, IFN-λ₃: 2 μg) were inoculated into asthmatic mice after OVA challenge by intranasal delivery. Lungs of asthmatic mice were severely inflamed, with extensive inflammatory cell infiltration and increased goblet cell metaplasia with higher total lung resistance. Transcription of IL-4, IL-5, IL-13, and IL-17A was significantly higher until five days after the final OVA challenge. Asthmatic mice were administered recombinant IFN-λ via inhalation three times after the last challenge and the asthmatic mice showed improvement in lung histopathologic findings, and total lung resistance was maintained under normal range. IFN-λ inhalation exhibited significant decreases in Th2 and Th17 cytokine levels, and the populations of Th2 and Th17 cells were recovered from the lungs of asthmatic mice. Additionally, increase in IL-10 secretion from CD4 + Th cells population was observed in response to inhaled delivery of IFN-λ along with alterations in Th2 and Th17 cell-derived inflammation. Our findings show that inhaled delivery of IFN-λ can restrict airway inflammation in the lungs of asthmatic mice by controlling Th2- and Th17-mediated responses accompanied by regulation of IL-10 secretion even after asthma development.

Solving the Conundrum of Eosinophils in Alloimmunity

Eosinophils are bone-marrow-derived granulocytes known for their ability to facilitate clearance of parasitic infections and their association with asthma and other inflammatory diseases. The purpose of this review is to discuss the currently available human observational and animal experimental data linking eosinophils to the immunologic response in solid organ transplantation. First, we present observational human studies that demonstrate a link between transplantation and eosinophils yet were unable to define the exact role of this cell population. Next, we describe published experimental models and demonstrate a defined mechanistic role of eosinophils in downregulating the alloimmune response to murine lung transplants. The overall summary of this data suggests that further studies are needed to define the role of eosinophils in multiple solid organ allografts and points to the possibility of manipulating this cell population to improve graft survival.

Targeting ferroptosis as a vulnerability in pulmonary diseases

Ferroptosis is an iron-dependent regulated cell death marked by excessive oxidative phospholipids (PLs). The polyunsaturated fatty acids-containing phospholipids (PUFA-PLs) are highly susceptible to lipid peroxidation under oxidative stress. Numerous pulmonary diseases occurrences and degenerative pathologies are driven by ferroptosis. This review discusses the role of ferroptosis in the pathogenesis of pulmonary diseases including asthma, lung injury, lung cancer, fibrotic lung diseases, and pulmonary infection. Additionally, it is proposed that targeting ferroptosis is a potential treatment for pulmonary diseases, particularly drug-resistant lung cancer or antibiotic-resistant pulmonary infection, and reduces treatment-related adverse events.

Sex Steroids Effects on Asthma: A Network Perspective of Immune and Airway Cells

A multitude of evidence has suggested the differential incidence, prevalence and severity of asthma between males and females. A compilation of recent literature recognized sex differences as a significant non-modifiable risk factor in asthma pathogenesis. Understanding the cellular and mechanistic basis of sex differences remains complex and the pivotal point of this ever elusive quest, which remains to be clarified in the current scenario. Sex steroids are an integral part of human development and evolution while also playing a critical role in the conditioning of the immune system and thereby influencing the function of peripheral organs. Classical perspectives suggest a pre-defined effect of sex steroids, generalizing estrogens popularly under the “estrogen paradox” due to conflicting reports associating estrogen with a pro- and anti-inflammatory role. On the other hand, androgens are classified as “anti-inflammatory,” serving a protective role in mitigating inflammation. Although considered mainstream and simplistic, this observation remains valid for numerous reasons, as elaborated in the current review. Women appear immune-favored with stronger and more responsive immune elements than men. However, the remarkable female predominance of diverse autoimmune and allergic diseases contradicts this observation suggesting that hormonal differences between the sexes might modulate the normal and dysfunctional regulation of the immune system. This review illustrates the potential relationship between key elements of the immune cell system and their interplay with sex steroids, relevant to structural cells in the pathophysiology of asthma and many other lung diseases. Here, we discuss established and emerging paradigms in the clarification of observed sex differences in asthma in the context of the immune system, which will deepen our understanding of asthma etiopathology.

Real-life effectiveness of dupilumab in patients with mild to moderate bronchial asthma comorbid with CRSwNP

BACKGROUND

Dupilumab, an anti-IL-4α receptor antibody, is a new treatment for severe or refractory asthma. However, real-world evidence on the efficacy of dupilumab in patients with mild to moderate bronchial asthma is lacking.

METHODS

We retrospectively evaluated the effects of dupilumab in 62 patients who received dupilumab for eosinophilic sinusitis comorbid with asthma at a single centre in Japan. Type 2 inflammatory markers, ACT, respiratory function tests, and forced oscillation technique (FOT) were analysed before, three months after, and one year after dupilumab administration, mainly in patients with mild to moderate asthma.

RESULTS

FEV1, %FEV1, %FVC, treatment steps for asthma and ACT improved significantly after three months of dupilumab treatment. FeNO was markedly decreased, whereas IgE and eosinophil counts showed no significant changes. Pre- and post-treatment respiratory resistance (Rrs) and respiratory reactance (Xrs) correlated significantly with FEV1. Improvement in %FEV1 was associated with higher FeNO and higher serum IgE before dupilumab treatment.

CONCLUSION

Dupilumab treatment for sinusitis may improve respiratory functions, asthma symptoms, and asthma treatment reduction, even if the associated bronchial asthma is not severe.

Molecular and Immunomodulatory Actions of New Antiasthmatic Agents: Exploring the Diversity of Biologics in Th2 Endotype Asthma

Asthma is a major respiratory disorder characterised by chronic inflammation and airway remodelling. It affects about 1-8% of the global population and is responsible for over 461,000 deaths annually. Until recently, the pharmacotherapy of severe asthma involved high doses of inhaled corticosteroids in combination with β-agonist for prolonged action, including theophylline, leukotriene antagonist or anticholinergic yielding limited benefit. Although the use of newer agents to target Th2 asthma endotypes has improved therapeutic outcomes in severe asthmatic conditions, there seems to be a paucity of understanding the diverse mechanisms through which these classes of drugs act. This article delineates the molecular and immunomodulatory mechanisms of action of new antiasthmatic agents currently being trialled in preclinical and clinical studies to remit asthmatic conditions. The ultimate goal in developing antiasthmatic agents is based on two types of approaches: either anti-inflammatory or bronchodilators. Biologic and most small molecules have been shown to modulate specific asthma endotypes, targeting thymic stromal lymphopoietin, tryptase, spleen tyrosine kinase (Syk), Janus kinase, PD-L1/PD-L2, GATA-3, and CD38 for the treatment and management of Th2 endotype asthma.

Characteristics, phenotypes, mechanisms and management of severe asthma

ABSTRACT

Severe asthma is "asthma which requires treatment with high dose inhaled corticosteroids (ICS) plus a second controller (and/or systemic corticosteroids) to prevent it from becoming 'uncontrolled' or which remains 'uncontrolled' despite this therapy." The state of control was defined by symptoms, exacerbations and the degree of airflow obstruction. Therefore, for the diagnosis of severe asthma, it is important to have evidence for a diagnosis of asthma with an assessment of its severity, followed by a review of comorbidities, risk factors, triggers and an assessment of whether treatment is commensurate with severity, whether the prescribed treatments have been adhered to and whether inhaled therapy has been properly administered. Phenotyping of severe asthma has been introduced with the definition of a severe eosinophilic asthma phenotype characterized by recurrent exacerbations despite being on high dose ICS and sometimes oral corticosteroids, with a high blood eosinophil count and a raised level of nitric oxide in exhaled breath. This phenotype has been associated with a Type-2 (T2) inflammatory profile with expression of interleukin (IL)-4, IL-5, and IL-13. Molecular phenotyping has also revealed non-T2 inflammatory phenotypes such as Type-1 or Type-17 driven phenotypes. Antibody treatments targeted at the T2 targets such as anti-IL5, anti-IL5Rα, and anti-IL4Rα antibodies are now available for treating severe eosinophilic asthma, in addition to anti-immunoglobulin E antibody for severe allergic asthma. No targeted treatments are currently available for non-T2 inflammatory phenotypes. Long-term azithromycin and bronchial thermoplasty may be considered. The future lies with molecular phenotyping of the airway inflammatory process to refine asthma endotypes for precision medicine.

Astegolimab, an anti-ST2, in chronic obstructive pulmonary disease (COPD-ST2OP): a phase 2a, placebo-controlled trial

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous inflammatory airway disease. The epithelial-derived IL-33 and its receptor ST2 have been implicated in airway inflammation and infection. We aimed to determine whether astegolimab, a selective ST2 IgG2 monoclonal antibody, reduces exacerbations in COPD.

METHODS

COPD-ST2OP was a single-centre, randomised, double-blinded, placebo-controlled phase 2a trial in moderate-to-very severe COPD. Participants were randomly assigned (1:1) with a web-based system to received 490 mg subcutaneous astegolimab or subcutaneous placebo, every 4 weeks for 44 weeks. The primary endpoint was exacerbation rate assessed for 48 weeks assessed with a negative binomial count model in the intention-to-treat population, with prespecified subgroup analysis by baseline blood eosinophil count. The model was the number of exacerbations over the 48-week treatment period, with treatment group as a covariate. Safety was assessed in the whole study population until week 60. Secondary endpoints included Saint George's Respiratory Questionnaire for COPD (SGRQ-C), FEV₁, and blood and sputum cell counts. The trial was registered with ClinicalTrials.gov, NCT03615040.

FINDINGS

The exacerbation rate at 48 weeks in the intention-to-treat analysis was not significantly different between the astegolimab group (2·18 [95% CI 1·59 to 2·78]) and the placebo group (2·81 [2·05 to 3·58]; rate ratio 0·78 [95% CI 0·53 to 1·14]; p=0·19]). In the prespecified analysis stratifying patients by blood eosinophil count, patients with 170 or fewer cells per μL had 0·69 exacerbations (0·39 to 1·21), whereas those with more than 170 cells per μL had 0·83 exacerbations (0·49 to 1·40). For the secondary outcomes, the mean difference between the SGRQ-C in the astegolimab group versus placebo group was -3·3 (95% CI -6·4 to -0·2; p=0·039), and mean difference in FEV₁ between the two groups was 40 mL (-10 to 90; p=0·094). The difference in geometric mean ratios between the two groups for blood eosinophil counts was 0·59 (95% CI 0·51 to 0·69; p<0·001) and 0·25 (0·19 to 0·33; p<0·001) for sputum eosinophil counts. Incidence of treatment-emergent adverse events was similar between groups.

INTERPRETATION

In patients with moderate-to-very severe COPD, astegolimab did not significantly reduce exacerbation rate, but did improve health status compared with placebo.

FUNDING

Funded by Genentech and National Institute for Health Research Biomedical Research Centres.

Gender dimorphism in IgA subclasses in T2-high asthma

Immunoglobulin A (Chan in J Allergy Clin Immunol 134:1394-14014e4, 2014), the second most abundant immunoglobulin in serum, plays an important role in mucosal homeostasis. In human serum, there are two subclasses of IgA, IgA1 (≅ 90%) and IgA2 (≅ 10%), transcribed from two distinct heavy chain constant regions. This study evaluated the serum concentrations of total IgA, IgA1, and IgA2, and total IgG, IgG1, IgG2, IgG3, and IgG4 in T2-high asthmatics compared to healthy controls and the presence of gender-related variations of immunoglobulins. Total IgA levels were increased in asthmatics compared to controls. Even more marked was the increase in total IgA in male asthmatics compared to healthy male donors. IgA1 were increased only in male, but not in female asthmatics, compared to controls. Concentrations of IgG2, but not IgG1, IgG3, and IgG4, were reduced in asthmatics compared to controls. IgG4 levels were reduced in female compared to male asthmatics. In female asthmatics, IgA and IgA1 levels were increased in postmenopause compared to premenopause. IgA concentrations were augmented in mild, but not severe asthmatics. A positive correlation was found between IgA levels and the age of patients and an inverse correlation between serum concentrations of IgA2 and IgE in asthmatics. A positive correlation between total IgA or IgA2 and IgG2 was found in asthmatics. These results highlight a gender dimorphism in IgA subclasses in male and female T2-high asthmatics. More adequate consideration of immunological gender disparity in asthma may open new opportunities in personalized medicine by optimizing diagnosis and targeted therapy.