Biologics and airway remodeling in severe asthma

Gleditsiae Sinensis Fructus ingredients and mechanism in anti-asthmatic bronchitis research

BACKGROUND

Gleditsiae Sinensis Fructus (GSF) is commonly used in traditional medicine to treat respiratory diseases such as bronchial asthma. However, there is a lack of research on the chemical composition of GSF and the pharmacological substance and mechanism of action for GSF in treating bronchial asthma.

PURPOSE

The chemical constituents of GSF were analyzed using ultrahigh-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). In this study, we combined network pharmacology, molecular docking techniques, and experimental validation to explore the therapeutic efficacy and underlying mechanism of GSF in the treatment of bronchial asthma.

METHODS

Characterization of the chemical constituents of GSF was conducted using UHPLC-Q-Orbitrap HRMS. The identified chemical components were subjected to screening for active ingredients in the Swiss Absorption, Distribution, Metabolism, and Excretion (ADME) database. Relevant databases were utilized to retrieve target proteins for the active ingredients and targets associated with bronchial asthma disease, and the common targets between the two were selected. Subsequently, the protein-protein interaction (PPI) network was constructed using the String database and Cytoscape software to identify key targets. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the Metascape database. The "component-common target" network was constructed using Cytoscape to identify the primary active ingredients. Molecular docking validation was conducted using AutoDock software. The bronchial asthma mouse model was established using ovalbumin (OVA), and the lung organ index of the mice was measured. Lung tissue pathological changes were observed using hematoxylin and eosin (HE), Periodic Acid-Schiff (PAS), and Masson staining. The respiratory resistance (Penh) of the mice was assessed using a pulmonary function test instrument. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of IgE, IL-4, IL-5, and IL-13 in the mouse serum. Immunofluorescence staining was performed to detect the protein expression levels of AKT and PI3K in the lung tissues. An in vitro experiment was performed to observe the effects of echinocystic acid (EA) on IL-4 stimulated Human ASMCs (hASMCs). Cell viability was measured using a CCK-8 assay to calculate the IC50 value of the EA. A wound healing test was conducted to observe the effect of EA on degree of healing. RT-qPCR was performed to detect the influence of EA on the mRNA expression levels of ALB, SRC, TNF-α, AKT1, and IL6 in the cells.

RESULTS

A total of 95 chemical constituents were identified from the GSF. Of these, 37 were identified as active ingredients. There were 169 overlapping targets between the active ingredients and the disease targets. A topological analysis of the protein-protein interaction (PPI) network identified the core targets as IL6, TNF, ALB, AKT1, and SRC. An enrichment analysis revealed that the treatment of bronchial asthma with GSF primarily involved the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway, among others. The primary active ingredients included 13(s)-HOTRE, linolenic acid, and acacetin. The molecular docking results demonstrated a favorable binding activity between the critical components of GSF and the core targets. Animal experimental studies indicated that GSF effectively improved symptoms, lung function, and lung tissue pathological changes in the OVA-induced asthmatic mice, while alleviating inflammatory responses. GSF decreased the fluorescent intensity of the AKT and PI3K proteins. The IC50 value of EA was 30.02μg/ml. EA (30) significantly promoted the proliferation of IL4-stimulated hASMCs cells. EA (30) significantly increased the expression of ALB and SRC mRNA and decreased the expressions of TNF-α, AKT, and IL6 mRNA.

CONCLUSION

The multiple active ingredients found in GSF exerted their anti-inflammatory effects through multiple targets and pathways. This preliminary study revealed the core target and the mechanism of action underlying its treatment of bronchial asthma. These findings provided valuable insights for further research on the pharmacological substances and quality control of GSF.

Therapeutic relevance of eosinophilic inflammation and airway viral interactions in severe asthma

The role of eosinophils in airway inflammation and asthma pathogenesis is well established, with raised eosinophil counts in blood and sputum associated with increased disease severity and risk of asthma exacerbation. Conversely, there is also preliminary evidence suggesting antiviral properties of eosinophils in the airways. These dual roles for eosinophils are particularly pertinent as respiratory virus infections contribute to asthma exacerbations. Biologic therapies targeting key molecules implicated in eosinophil-associated pathologies have been approved in patients with severe asthma and, therefore, the effects of depleting eosinophils in a clinical setting are of considerable interest. This review discusses the pathological and antiviral roles of eosinophils in asthma and exacerbations. We also highlight the significant reduction in asthma exacerbations seen with biologic therapies, even at the height of the respiratory virus season. Furthermore, we discuss the implications of these findings in relation to the role of eosinophils in inflammation and antiviral responses to respiratory virus infection in asthma.

[Highlights 57th SEPAR Congress]

The Spanish Society of Pneumology and Thoracic Surgery (SEPAR) has held its 57th Congress in Valencia from 6 to 8 of June 2024. The SEPAR Congress is the leading meeting for the entire respiratory scientific community, which allows learning about the main scientific advances in this area and provides the ideal situation to create and strengthen ties. This year, under the title "Respiratory Health for everybody", the SEPAR Congress stressed the importance of raising awareness about the importance of caring for and protecting our respiratory system. In this review, we offer a summary of some notable issues addressed in six selected areas of interest: chronic obstructive pulmonary disease (COPD), asthma, interstitial lung diseases (ILDs), pulmonary vascular diseases, sleep and breathing disorders and respiratory physiotherapy.

Lipidomic profiling of amniotic fluid reveals aberrant fetal lung development and fetal growth disrupted by lipid disorders during gestational asthma

This study aimed to investigate how maternal asthma during pregnancy disrupts fetal lung development by altering lipid metabolism in the amniotic fluid, which is crucial for fetal development. A pregnancy-induced asthma model was established in female rats using house dust mite (HDM) as a common allergen. The fetuses were divided into four groups based on whether the mother and fetus were exposed to the allergen: PBS+PBS, PBS+HDM, HDM+PBS, and HDM+HDM. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was employed to analyze changes in the lipid profile of the amniotic fluid and bronchoalveolar lavage fluid (BALF). Principal component analysis (PCA) and ChemRICH methods were used to explore the potential relationship between lipid metabolism abnormalities and impaired fetal lung development. The results indicate that maternal asthma exacerbates asthma-related inflammatory markers in fetuses, leading to pathological changes in the lungs and elevated levels of cytokines IL-5, IL-13, and IgE. Additionally, 18 differential lipids, primarily oxygenated lipids, were identified in the amniotic fluid after modeling, suggesting an enhanced oxidative stress environment for the fetus. This environment causes metabolic disturbances in various lipid groups in fetal lungs, with the HDM+HDM group showing significant abnormalities in lipids critical for lung development, including phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and fatty acids (FA). In conclusion, gestational asthma can reshape the lipid profile in the amniotic fluid and BALF, significantly disrupting fetal growth and lung development. Restoring normal lipid metabolism in the amniotic fluid and fetal lungs may offer a potential therapeutic approach to managing aberrant fetal lung development in asthmatic mothers.

Correlation analysis of serum Rac1 level with asthma control, airway inflammatory response and lung function in asthmatic children

OBJECTIVE

To investigate the correlation between serum Rac1 enzyme (Rac1) level with asthma control, airway inflammatory response and lung function in asthmatic children.

METHODS

A retrospective analysis was performed on 79 children with asthma who were diagnosed and treated in our hospital from June 2020 to January 2023. According to the severity of the disease, the children were divided into mild group (25 cases), moderate group (30 cases) and severe group (24 cases). 36 healthy children who underwent physical examination at the same period in our hospital were selected as the control group. The state of an illness, control level, serum mRNA Rac1, inflammatory factors, and lung function of the children in two groups were compared between the control group and the observation group.

RESULTS

The Rac1 mRNA levels, forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), peak expiratory flow (PEF), and maximum mid-expiratory flow (MMEF) in the observation group were significantly lower than these in the control group (P < 0.05). The tumor necrosis factor-alpha (TNF-α), interleukin-5 (IL-5), IL-6, and IL-33 in the observation group were markedly higher than these in the control group (P < 0.05). As the state of an illness worsened, the Rac1 mRNA levels, FVC, FEV1/FVC, PEF, and MMEF gradually reduced (P < 0.05), while the levels of TNF-α, IL-5, IL-6, and IL-33 increased (P < 0.05). As the degree of disease control improved, the Rac1 mRNA levels, FVC, FEV1/FVC, PEF, and MMEF gradually elevated (P < 0.05), and the levels of TNF- α, IL-5, IL-6, and IL-33 showed the opposite trend (P < 0.05). Rac1 was negatively related to the levels of TNF-α, IL-5, IL-6 and IL-33 (P < 0.05), and positively to the levels of FVC, FEV1/FVC, PEF and MMEF (P < 0.001). Rac1 mRNA levels, FVC, FEV1/FVC, PEF and MMEF were protective factors, while TNF-α, IL-5, IL-6 and IL-33 were risk factors for the prognosis of children with asthma (P < 0.05).

CONCLUSION

Children with asthma have obviously lower serum Rac1 mRNA levels, higher inflammatory factor levels and lower lung function. Serum Rac1 mRNA level may be associated with better asthma control, lower airway inflammatory response, better lung function and lower disease severity. It has important reference value for the evaluation of the state of an illness, efficacy and prognosis of children with bronchial asthma.

Atomized inhalation of Icaritin reduces airway inflammation and remodeling in asthmatic mice

BACKGROUND

Asthma is a disease characterized by airway hyperresponsiveness and airway inflammation. Icaritin (ICT) is a plant hormone with various pharmacological activities such as anti-inflammatory, immune regulation, and anti-tumor. This study mainly explored the effects of nebulized inhalation of ICT on airway inflammation and airway remodeling in asthmatic mice.

METHOD

Different groups of ovalbumin (OVA)-induced asthma mice with acute and chronic airway inflammation received ICT. Asthmatic mice received budesonide (BDND) aerosol inhalation as a positive control, while normal control and asthma model mice received the same volume of saline. Following finishing of the study, analyses were conducted on behavioral tests, biochemical indices, and histological structures of lung tissues.

RESULTS

Aerosol inhalation of ICT can notably reduce inflammatory cells infiltration around the airways and pulmonary vessels, and suppressed goblet cell hyperplasia in asthmatic mice. Long-term inhalation of ICT can decrease airway collagen deposition and airway smooth muscle hyperplasia, and alleviate airway hyperresponsiveness, mirroring the effects observed with hormone employed in clinical practice.

CONCLUSION

Nebulized inhalation of ICT can effectively inhibit airway inflammation in asthmatic mice, improve airway remodeling, and reduce airway hyperresponsiveness, with effects similar to those of hormones. It may serve as a potential candidate used as a hormone replacement asthma treatment.

Toll-like receptor 4 mediated autophagy regulates airway smooth muscle cells behavior

OBJECTIVES

Airway remodeling, a prominent feature of asthma, involves aberrant proliferation, apoptosis, and migration of airway smooth muscle cells (ASMCs). Toll-like receptors (TLRs) are implicated in the regulation of the autophagy pathway. In this study, we aimed to investigate the influence of Toll-like receptor 4 (TLR4) on autophagy and its underlying mechanism in ASMC proliferation, apoptosis, and migration.

METHODS

Histopathological changes in the lungs of asthmatic mice assessed by Hematoxylin-Eosin (HE) and Masson staining. Cell proliferation, apoptosis and migration were evaluated utilizing CCK8, Edu, Flow cytometry and wound heading assays. The effectiveness of siRNA transfection and the expression of TLR4, autophagy, and proliferation-related proteins after siRNA treatment were examined through RT-PCR and Western blot (WB).

CONCLUSION

We observed an increase in TLR4 expression and autophagy in a mouse model of OVA-induced asthma. In vitro experiments showed that siRNA-mediated inhibition of TLR4 suppressed autophagy, proliferation, and migration of ASMCs, whereas TLR4 activation by lipopolysaccharide (LPS) had the opposite effect. Furthermore, the autophagy inhibitor 3-Methyladenine (3MA) inhibited ASMCs proliferation and migration while promoting apoptosis. Significantly, our study demonstrated that autophagy inhibition reversed the promotion effect of LPS on ASMC proliferation and migration. These findings suggest that TLR4 may modulate ASMC behavior through the regulation of autophagy.

Crosstalk between ROS-inflammatory gene expression axis in the progression of lung disorders

A significant number of deaths and disabilities worldwide are brought on by inflammatory lung diseases. Many inflammatory lung disorders, including chronic respiratory emphysema, resistant asthma, resistance to steroids, and coronavirus-infected lung infections, have severe variants for which there are no viable treatments; as a result, new treatment alternatives are needed. Here, we emphasize how oxidative imbalance contributes to the emergence of provocative lung problems that are challenging to treat. Endogenic antioxidant systems are not enough to avert free radical-mediated damage due to the induced overproduction of ROS. Pro-inflammatory mediators are then produced due to intracellular signaling events, which can harm the tissue and worsen the inflammatory response. Overproduction of ROS causes oxidative stress, which causes lung damage and various disease conditions. Invasive microorganisms or hazardous substances that are inhaled repeatedly can cause an excessive amount of ROS to be produced. By starting signal transduction pathways, increased ROS generation during inflammation may cause recurrent DNA damage and apoptosis and activate proto-oncogenes. This review provides information about new targets for conducting research in related domains or target factors to prevent, control, or treat such inflammatory oxidative stress-induced inflammatory lung disorders.

The JAK1/JAK2 inhibitor ruxolitinib inhibits mediator release from human basophils and mast cells

Introduction

The Janus kinase (JAK) family includes four cytoplasmic tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) constitutively bound to several cytokine receptors. JAKs phosphorylate downstream signal transducers and activators of transcription (STAT). JAK-STAT5 pathways play a critical role in basophil and mast cell activation. Previous studies have demonstrated that inhibitors of JAK-STAT pathway blocked the activation of mast cells and basophils.

Methods

In this study, we investigated the in vitro effects of ruxolitinib, a JAK1/2 inhibitor, on IgE- and IL-3-mediated release of mediators from human basophils, as well as substance P-induced mediator release from skin mast cells (HSMCs).

Results

Ruxolitinib concentration-dependently inhibited IgE-mediated release of preformed (histamine) and de novo synthesized mediators (leukotriene C4) from human basophils. Ruxolitinib also inhibited anti-IgE- and IL-3-mediated cytokine (IL-4 and IL-13) release from basophils, as well as the secretion of preformed mediators (histamine, tryptase, and chymase) from substance P-activated HSMCs.

Discussion

These results indicate that ruxolitinib, inhibiting the release of several mediators from human basophils and mast cells, is a potential candidate for the treatment of inflammatory disorders.

Reshaping respiratory care: potential advances in inhaled pharmacotherapy in asthma

INTRODUCTION

Asthma is a common disease with a global burden of 358 million patients. Despite improvements in pharmacological and non-pharmacological treatments, many patients still do not achieve complete asthma control. Therefore, innovative pharmacotherapy is important.

AREAS COVERED

Following a semi-structured search in Pubmed, an overview of advances in inhaled asthma therapy is provided, looking at innovations in digital inhalers, eco-friendly inhalers and novel inhaled biologic therapies, antibiotics and vaccines, as well as other potential novel asthma therapy targets.

EXPERT OPINION

Digital inhalers, sending reminders and monitoring inhalation technique electronically, can support medication adherence and improve asthma control. To reduce the global warming potential of traditional aerosols used in pressurized metered-dose inhalers (HFA-134a, HFA-227ea), greener alternatives are under development (HFA-152a, HFO-1234ze) that are expected to be available by 2025. Current pharmacological advances in asthma therapy are mainly achieved by novel biologicals (anti-IgE, anti-IL5, anti-IL4/13, and anti-TSLP) targeting specific severe asthma phenotypes. While injection is the usual administration route for biologics and vaccines used in asthma, inhalation is an option being explored, although several (mainly formulation) challenges need to be overcome. Other potential novel future inhaled asthma therapies include anti-IL-33/ST2 biologicals and JAK inhibitors, all still requiring more clinical evidence.

Molecular Pathways and Potential Therapeutic Targets of Refractory Asthma

Asthma is a chronic inflammatory lung disease. Refractory asthma poses a significant challenge in management due to its resistance to standard therapies. Key molecular pathways of refractory asthma include T2 inflammation mediated by Th2 and ILC2 cells, eosinophils, and cytokines including IL-4, IL-5, and IL-13. Additionally, non-T2 mechanisms involving neutrophils, macrophages, IL-1, IL-6, and IL-17 mediate a corticosteroid resistant phenotype. Mediators including alarmins (IL-25, IL-33, TSLP) and OX40L have overlap between T2 and non-T2 inflammation and may signify unique pathways of asthma inflammation. Therapies that target these pathways and mediators have proven to be effective in reducing exacerbations and improving lung function in subsets of severe asthma patients. However, there are patients with severe asthma who do not respond to approved therapies. Small molecule inhibitors, such as JAK-inhibitors, and monoclonal antibodies targeting mast cells, IL-1, IL-6, IL-33, TNFα, and OX40L are under investigation for their potential to modulate inflammation involved in refractory asthma. Understanding refractory asthma heterogeneity and identifying mediators involved are essential in developing therapeutic interventions for patients unresponsive to currently approved biologics. Further investigation is needed to develop personalized treatments based on these molecular insights to potentially offer more effective treatments for this complex disease.

Efficacy of Biologics in Patients with Allergic Bronchopulmonary Aspergillosis: A Systematic Review and Meta-Analysis

BACKGROUND

Treatment of allergic bronchopulmonary aspergillosis (ABPA) is challenging. Biological therapies have been reported as adjunctive treatments for ABPA, primarily in case series or case reports. This study aimed to analyze the efficacy of biologics for managing ABPA both qualitatively and quantitatively.

METHODS

All articles on APBA published in October 2023 were searched in PubMed, Web of Science, ClinicalTrials.gov, and Embase databases. The effects of interest were the mean changes from baseline for outcomes, including exacerbation rates, oral corticosteroids usage (OCS), and total immunoglobulin E (IgE) levels. Reported outcomes were quantitatively synthesized by usual or individual patient data (IPD) meta-analyses. PROSPERO registration number: CRD42022373396.

RESULTS

A total of 86 studies were included in the systematic review including 346 patients. Sixteen studies on omalizumab were pooled for the usual meta-analysis. Omalizumab therapy significantly reduced exacerbation rates (- 2.29 [95%CI - 3.32, - 1.26]), OCS dosage (- 10.91 mg [95%CI - 18.98, - 2.85]), and total IgE levels (- 273.07 IU/mL [95%CI - 379.30, - 166.84]), meanwhile improving FEV1% predicted (10.09% [95%CI 6.62, 13.55]). Thirty-one studies on dupilumab, mepolizumab, or benralizumab were pooled to perform an IPD meta-analysis, retrospectively. Both dupilumab and mepolizumab significantly reduced exacerbation rates, OCS, and total IgE levels. Benralizumab showed a similar trend, but it was not statistically significant. Tezepelumab showed weak evidence of its effects on ABPA. All five biologics led to milder clinical symptoms (e.g., cough, wheezing) with serious adverse effects that happened once in omalizumab treatment.

CONCLUSION

These results indicate the clinical benefit of omalizumab, dupilumab, and mepolizumab in patients with ABPA. Further randomized, controlled studies with a larger sample size and longer follow-up are needed to confirm these findings.

Role of STIM1 in stretch-induced signaling in human airway smooth muscle

Alteration in the normal mechanical forces of breathing can contribute to changes in contractility and remodeling characteristic of airway diseases, but the mechanisms that mediate these effects in airway cells are still under investigation. Airway smooth muscle (ASM) cells contribute to both contractility and extracellular matrix (ECM) remodeling. In this study, we explored ASM mechanisms activated by mechanical stretch, focusing on mechanosensitive piezo channels and the key Ca2+ regulatory protein stromal interaction molecule 1 (STIM1). Expression of Ca2+ regulatory proteins, including STIM1, Orai1, and caveolin-1, mechanosensitive ion channels Piezo-1 and Piezo-2, and NLRP3 inflammasomes were upregulated by 10% static stretch superimposed on 5% cyclic stretch. These effects were blunted by STIM1 siRNA. Histamine-induced [Ca2+]i responses and inflammasome activation were similarly blunted by STIM1 knockdown. These data show that the effects of mechanical stretch in human ASM cells are mediated through STIM1, which activates multiple pathways, including Piezo channels and the inflammasome, leading to potential downstream changes in contractility and ECM remodeling.NEW & NOTEWORTHY Mechanical forces on the airway can contribute to altered contractility and remodeling in airway diseases, but the mechanisms are not clearly understood. Using human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic breathing and static pressure, we found that the effects of stretch are mediated through STIM1, resulting in the activation of multiple pathways, including Piezo channels and the inflammasome, with potential downstream influences on contractility and remodeling.

Research progress of airway inflammation in asthma: A bibliometric analysis

BACKGROUND

In recent years, the prevalence of asthma has gradually increased and the number of asthmatics worldwide has reached 358 million, which has caused huge economic loss. Airway inflammation is an important feature of asthma, and international research in this field has a high degree of heat. Therefore, this paper uses the bibliometric method to systematically review and visualize the literature in this field, aiming to provide some reference value for follow-up related research.

METHODS

To retrieve the research literature on airway inflammation in asthma from 2003 to 2022 in the Web of Science Core Collection database. The bibliometric method was used to systematically analyze the included literature data by using visualization analysis software such as CiteSpace (6.2. R4) and VOSviewer (1.6.19).

RESULTS

A total of 1892 articles published in 423 journals were included in this study, from 1912 institutions in 62 countries/regions. The number of articles published between 2003 and 2022 showed a trend of fluctuating growth. The country with the largest number of articles published was China (558,29.49 %), followed by the United States (371,19.61 %) and Korea (212,11.21 %). Gibson, Peter G is the author with the highest number of publications, and Journal of Allergy and Clinical Immunology is the most published journal.

CONCLUSION SUBSECTIONS

This study systematically reveals the state of the literature in the field of airway inflammation in asthma over the past 20 years. The exploration of inflammatory cell components, pathway molecules and biological agents are research hotspots in this field and should be further studied.

Towards precision medicine in COPD: Targeting type 2 cytokines and alarmins

Chronic obstructive pulmonary disease (COPD) is a main global epidemic increasing as population age and affecting approximately 10% of subjects over 45 years. COPD is a heterogeneous inflammatory disease with several endo-phenotypes and clinical presentations. Although neutrophilic inflammation is canonically considered a hallmark of COPD, eosinophilic inflammation can also be present in a subgroup of patients. Several other immune cells and cytokines play a key role in orchestrating and perpetuating the inflammatory pathways in COPD, making them attractive targets for treating this disorder. Recent studies have started to evaluate the possible role of type 2 (T2) inflammation and epithelial-derived alarmins (TSLP and IL-33) in COPD. Two phase III randomized clinical trials (RCTs) showed a modest reduction in exacerbations in COPD patients with eosinophilic phenotype treated with mepolizumab (anti-IL-5) or benralizumab (anti-IL-5Rα). A phase III RCT showed a 30% reduction in exacerbations in COPD patients with ≥ 300 eosinophils/μL treated with dupilumab (anti-IL-4Rα). These results suggest that blocking a single cytokine (e.g., IL-5) or its main target (i.e., IL-5Rα) is less promising than blocking a wider spectrum of cytokines (i.e., IL-4 and IL-13) in COPD. TSLP and IL-33 are upstream regulators of T2-high and T2-low immune responses in airway inflammation. Several ongoing RCTs are evaluating the efficacy and safety of anti-TSLP (tezepelumab), anti-IL-33 (itepekimab, tozorakimab), and anti-ST2 (astegolimab) in patients with COPD, who experience exacerbations. In conclusion, targeting T2 inflammation or epithelial-derived alarmins might represent a step forward in precision medicine for the treatment of a subset of COPD.

Efficacy of dupilumab for airway hypersecretion and airway wall thickening in patients with moderate-to-severe asthma: A prospective, observational study

BACKGROUND

Dupilumab has clinical effects in patients with moderate-to-severe asthma. When considering interleukin (IL)-4 and IL-13 signaling, effects of dupilumab on airway mucus hypersecretion and airway remodeling are expected, but they have been reported in only a few short-term studies. Its efficacy for airway hyperresponsiveness (AHR) remains unknown. We comprehensively assessed the efficacy of dupilumab, especially for subjective and objective measures of airway mucus hypersecretion and airway dimensions in moderate-to-severe asthmatic patients.

METHODS

In 28 adult patients with moderate-to-severe uncontrolled asthma, the comprehensive efficacy of 48-week dupilumab treatment, including the Cough and Sputum Assessment Questionnaire (CASA-Q), radiological mucus scores and airway dimensions on computed tomography (CT), was assessed prospectively. Treatment responsiveness to dupilumab was analyzed.

RESULTS

With 48-week dupilumab treatment, all four cough and sputum domain scores of CASA-Q improved significantly. Radiological mucus scores and airway wall thickening on CT were significantly decreased. The decreases in mucus scores were significantly associated with improvements in Asthma Control Questionnaire scores, Asthma Quality of Life Questionnaire (AQLQ) overall scores, airway obstruction, and airway type 2 inflammation. When defined by > 0.5 improvement in AQLQ overall scores, 18 patients (64%) were identified as responders.

CONCLUSIONS

Dupilumab reversed subjective and objective measures of airway mucus hypersecretion and some aspects of airway remodeling in patients with moderate-to-severe uncontrolled asthma.

Rosuvastatin attenuates airway inflammation and remodeling in a chronic allergic asthma model through modulation of the AMPKα signaling pathway

The efficacy of rosuvastatin in reducing allergic inflammation has been established. However, its potential to reduce airway remodeling has yet to be explored. This study aimed to evaluate the efficacy of rosuvastatin in reducing airway inflammation and remodeling in a mouse model of chronic allergic asthma induced by sensitization and challenge with OVA. Histology of the lung tissue and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) showed a marked decrease in airway inflammation and remodeling in mice treated with rosuvastatin, as evidenced by a decrease in goblet cell hyperplasia, collagen deposition, and smooth muscle hypertrophy. Furthermore, levels of inflammatory cytokines, angiogenesis-related factors, and OVA-specific IgE in BALF, plasma, and serum were all reduced upon treatment with rosuvastatin. Western blotting was employed to detect AMPK expression, while immunohistochemistry staining was used to observe the expression of remodeling signaling proteins such as α-SMA, TGF-β, MMP-9, and p-AMPKα in the lungs. It was found that the activity of 5'-adenosine monophosphate-activated protein kinase alpha (AMPKα) was significantly lower in the lungs of OVA-induced asthmatic mice compared to Control mice. However, the administration of rosuvastatin increased the ratio of phosphorylated AMPK to total AMPKα, thus inhibiting the formation of new blood vessels, as indicated by CD31-positive staining mainly in the sub-epithelial region. These results indicate that rosuvastatin can effectively reduce airway inflammation and remodeling in mice with chronic allergic asthma caused by OVA, likely due to the reactivation of AMPKα and a decrease in angiogenesis.

Deciphering the Interplay between the Epithelial Barrier, Immune Cells, and Metabolic Mediators in Allergic Disease

Chronic exposure to harmful pollutants, chemicals, and pathogens from the environment can lead to pathological changes in the epithelial barrier, which increase the risk of developing an allergy. During allergic inflammation, epithelial cells send proinflammatory signals to group 2 innate lymphoid cell (ILC2s) and eosinophils, which require energy and resources to mediate their activation, cytokine/chemokine secretion, and mobilization of other cells. This review aims to provide an overview of the metabolic regulation in allergic asthma, atopic dermatitis (AD), and allergic rhinitis (AR), highlighting its underlying mechanisms and phenotypes, and the potential metabolic regulatory roles of eosinophils and ILC2s. Eosinophils and ILC2s regulate allergic inflammation through lipid mediators, particularly cysteinyl leukotrienes (CysLTs) and prostaglandins (PGs). Arachidonic acid (AA)-derived metabolites and Sphinosine-1-phosphate (S1P) are significant metabolic markers that indicate immune dysfunction and epithelial barrier dysfunction in allergy. Notably, eosinophils are promoters of allergic symptoms and exhibit greater metabolic plasticity compared to ILC2s, directly involved in promoting allergic symptoms. Our findings suggest that metabolomic analysis provides insights into the complex interactions between immune cells, epithelial cells, and environmental factors. Potential therapeutic targets have been highlighted to further understand the metabolic regulation of eosinophils and ILC2s in allergy. Future research in metabolomics can facilitate the development of novel diagnostics and therapeutics for future application.

Targeting lysyl oxidase like 2 attenuates OVA-induced airway remodeling partly via the AKT signaling pathway

BACKGROUND

Airway epithelium is an important component of airway structure and the initiator of airway remodeling in asthma. The changes of extracellular matrix (ECM), such as collagen deposition and structural disturbance, are typical pathological features of airway remodeling. Thus, identifying key mediators that derived from airway epithelium and capable of modulating ECM may provide valuable insights for targeted therapy of asthma.

METHODS

The datasets from Gene Expression Omnibus database were analyzed to screen differentially expressed genes in airway epithelium of asthma. We collected bronchoscopic biopsies and serum samples from asthmatic and healthy subjects to assess lysyl oxidase like 2 (LOXL2) expression. RNA sequencing and various experiments were performed to determine the influences of LOXL2 knockdown in ovalbumin (OVA)-induced mouse models. The roles and mechanisms of LOXL2 in bronchial epithelial cells were explored using LOXL2 small interfering RNA, overexpression plasmid and AKT inhibitor.

RESULTS

Both bioinformatics analysis and further experiments revealed that LOXL2 is highly expressed in airway epithelium of asthmatics. In vivo, LOXL2 knockdown significantly inhibited OVA-induced ECM deposition and epithelial-mesenchymal transition (EMT) in mice. In vitro, the transfection experiments on 16HBE cells demonstrated that LOXL2 overexpression increases the expression of N-cadherin and fibronectin and reduces the expression of E-cadherin. Conversely, after silencing LOXL2, the expression of E-cadherin is up-regulated. In addition, the remodeling and EMT process that induced by transforming growth factor-β1 could be enhanced and weakened after LOXL2 overexpression and silencing in 16HBE cells. Combining the RNA sequencing of mouse lung tissues and experiments in vitro, LOXL2 was involved in the regulation of AKT signaling pathway. Moreover, the treatment with AKT inhibitor in vitro partially alleviated the consequences associated with LOXL2 overexpression.

CONCLUSIONS

Taken together, the results demonstrated that epithelial LOXL2 plays a role in asthmatic airway remodeling partly via the AKT signaling pathway and highlighted the potential of LOXL2 as a therapeutic target for airway remodeling in asthma.

CAR-NKT Cells in Asthma: Use of NKT as a Promising Cell for CAR Therapy

NKT cells, unique lymphocytes bridging innate and adaptive immunity, offer significant potential for managing inflammatory disorders like asthma. Activating iNKT induces increasing IFN-γ, TGF-β, IL-2, and IL-10 potentially suppressing allergic asthma. However, their immunomodulatory effects, including granzyme-perforin-mediated cytotoxicity, and expression of TIM-3 and TRAIL warrant careful consideration and targeted approaches. Although CAR-T cell therapy has achieved remarkable success in treating certain cancers, its limitations necessitate exploring alternative approaches. In this context, CAR-NKT cells emerge as a promising approach for overcoming these challenges, potentially achieving safer and more effective immunotherapies. Strategies involve targeting distinct IgE-receptors and their interactions with CAR-NKT cells, potentially disrupting allergen-mast cell/basophil interactions and preventing inflammatory cytokine release. Additionally, targeting immune checkpoints like PDL-2, inducible ICOS, FASL, CTLA-4, and CD137 or dectin-1 for fungal asthma could further modulate immune responses. Furthermore, artificial intelligence and machine learning hold immense promise for revolutionizing NKT cell-based asthma therapy. AI can optimize CAR-NKT cell functionalities, design personalized treatment strategies, and unlock a future of precise and effective care. This review discusses various approaches to enhancing CAR-NKT cell efficacy and longevity, along with the challenges and opportunities they present in the treatment of allergic asthma.

Succinate coenzyme A ligase β-like protein from Trichinella spiralis is a potential therapeutic molecule for allergic asthma

BACKGROUND

For decades, studies have demonstrated the anti-inflammatory potential of proteins secreted by helminths in allergies and asthma. Previous studies have demonstrated the immunomodulatory capabilities of Succinate Coenzyme A ligase beta-like protein (SUCLA-β) derived from Trichinella spiralis, a crucial excretory product of this parasite.

OBJECTIVE

To explore the therapeutic potential of SUCLA-β in alleviating and controlling ovalbumin (OVA)-induced allergic asthma, as well as its influence on host immune modulation.

METHODS

In this research, we utilized the rTs-SUCLA-β protein derived from T. spiralis to investigate its potential in mitigating airway inflammation in a murine model of asthma induced by OVA sensitization/stimulation, both pre- and post-challenge. The treatment's efficacy was assessed by quantifying the extent of inflammation in the lungs.

RESULTS

Treatment with rTs-SUCLA-β demonstrated efficacy in ameliorating OVA-induced airway inflammation, as evidenced by a reduction in eosinophil infiltration, levels of OVA-specific Immunoglobulin E, interferon-γ, interleukin (IL)-9, and IL-17A, along with an elevation in IL-10. The equilibrium between Th17 and Treg cells plays a pivotal role in modulating the abundance of inflammatory cells within the organism, thereby ameliorating inflammation and alleviating symptoms associated with allergic asthma.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data revealed that T. spiralis-derived Ts-SUCLA-β protein may inhibit the allergic airway inflammation by regulating host immune responses.

The role of radiological imaging in the management of severe and difficult-to-treat asthma

Radiological imaging has proven to be a useful tool in the assessment of asthma, its comorbidities and potential complications. Characteristic chest radiograph and computed tomography scan findings can be seen in asthma and in other conditions that can coexist with or be misdiagnosed as asthma, including chronic rhinosinusitis, inducible laryngeal obstruction, excessive dynamic airway collapse, tracheobronchomalacia, concomitant COPD, bronchiectasis, allergic bronchopulmonary aspergillosis, eosinophilic granulomatosis with polyangiitis, and eosinophilic pneumonia. The identification of the characteristic radiological findings of these conditions is often essential in making the correct diagnosis and provision of appropriate management and treatment. Furthermore, radiological imaging modalities can be used to monitor response to therapy.

TSLP is localized in and released from human lung macrophages activated by T2-high and T2-low stimuli: relevance in asthma and COPD

BACKGROUND

Macrophages are the predominant immune cells in the human lung and play a central role in airway inflammation, including asthma and chronic obstructive pulmonary disease (COPD). Thymic stromal lymphopoietin (TSLP), a pleiotropic cytokine mainly expressed by bronchial epithelial cells, plays a key role in asthma and COPD pathobiology. TSLP exists in two variants: the long form (lfTSLP) and a shorter TSLP isoform (sfTSLP). We aimed to localize TSLP in human lung macrophages (HLMs) and investigate the mechanisms of its release from these cells. We also evaluated the effects of the two variants of TSLP on the release of angiogenic factor from HLMs.

METHODS

We employed immunofluorescence and Western blot to localize intracellular TSLP in HLMs purified from human lung parenchyma. HLMs were activated by T2-high (IL-4, IL-13) and T2-low (lipopolysaccharide: LPS) immunological stimuli.

RESULTS

TSLP was detected in HLMs and subcellularly localized in the cytoplasm. IL-4 and LPS induced TSLP release from HLMs. Preincubation of macrophages with brefeldin A, known to disrupt the Golgi apparatus, inhibited TSLP release induced by LPS and IL-4. lfTSLP concentration-dependently induced the release of vascular endothelial growth factor-A (VEGF-A), the most potent angiogenic factor, from HLMs. sfTSLP neither activated nor interfered with the activating property of lfTSLP on macrophages.

CONCLUSIONS

Our results highlight a novel immunologic circuit between HLMs and TSLP. Given the central role of macrophages in airway inflammation, this autocrine loop holds potential translational relevance in understanding innovative aspects of the pathobiology of asthma and chronic inflammatory lung disorders.

Tezepelumab in a case of severe asthma exacerbation and influenza-pneumonia on VV-ECMO

We present a case of 43-year-old male patient with broadly by Omalizumab, Mepolizumab and Benralizumab pretreated allergic asthma, who suffered a near fatal exacerbation, triggered by an influenza A infection. Due to massive bronchoconstriction with consecutive hypercapnic ventilatory failure veno-venous ECMO therapy had to be implemented. Hence, guideline directed asthma therapy a substantial bronchodilatation could not be achieved. After administration of a single dose Tezepelumab, a novel TLSP-inhibitor, and otherwise unchanged therapy we documented a significant reduction in intrinsic PEEP measured via a naso-gastric balloon catheter and a narrowing in the expiratory flow curve of the ventilator within 24 hours. The consecutive ventilatory improvement allowed the successful weaning from veno-venous ECMO therapy and invasive ventilation.

Mast cells: a novel therapeutic avenue for cardiovascular diseases?

Mast cells are tissue-resident immune cells strategically located in different compartments of the normal human heart (the myocardium, pericardium, aortic valve, and close to nerves) as well as in atherosclerotic plaques. Cardiac mast cells produce a broad spectrum of vasoactive and proinflammatory mediators, which have potential roles in inflammation, angiogenesis, lymphangiogenesis, tissue remodelling, and fibrosis. Mast cells release preformed mediators (e.g. histamine, tryptase, and chymase) and de novo synthesized mediators (e.g. cysteinyl leukotriene C4 and prostaglandin D2), as well as cytokines and chemokines, which can activate different resident immune cells (e.g. macrophages) and structural cells (e.g. fibroblasts and endothelial cells) in the human heart and aorta. The transcriptional profiles of various mast cell populations highlight their potential heterogeneity and distinct gene and proteome expression. Mast cell plasticity and heterogeneity enable these cells the potential for performing different, even opposite, functions in response to changing tissue contexts. Human cardiac mast cells display significant differences compared with mast cells isolated from other organs. These characteristics make cardiac mast cells intriguing, given their dichotomous potential roles of inducing or protecting against cardiovascular diseases. Identification of cardiac mast cell subpopulations represents a prerequisite for understanding their potential multifaceted roles in health and disease. Several new drugs specifically targeting human mast cell activation are under development or in clinical trials. Mast cells and/or their subpopulations can potentially represent novel therapeutic targets for cardiovascular disorders.

The New Paradigm: The Role of Proteins and Triggers in the Evolution of Allergic Asthma

Epithelial barrier damage plays a central role in the development and maintenance of allergic inflammation. Rises in the epithelial barrier permeability of airways alter tissue homeostasis and allow the penetration of allergens and other external agents. Different factors contribute to barrier impairment, such as eosinophilic infiltration and allergen protease action-eosinophilic cationic proteins' effects and allergens' proteolytic activity both contribute significantly to epithelial damage. In the airways, allergen proteases degrade the epithelial junctional proteins, allowing allergen penetration and its uptake by dendritic cells. This increase in allergen-immune system interaction induces the release of alarmins and the activation of type 2 inflammatory pathways, causing or worsening the main symptoms at the skin, bowel, and respiratory levels. We aim to highlight the molecular mechanisms underlying allergenic protease-induced epithelial barrier damage and the role of immune response in allergic asthma onset, maintenance, and progression. Moreover, we will explore potential clinical and radiological biomarkers of airway remodeling in allergic asthma patients.

Airway hyperresponsiveness in asthma: The role of the epithelium

Airway hyperresponsiveness (AHR) is a key clinical feature of asthma. The presence of AHR in people with asthma provides the substrate for bronchoconstriction in response to numerous diverse stimuli, contributing to airflow limitation and symptoms including breathlessness, wheeze, and chest tightness. Dysfunctional airway smooth muscle significantly contributes to AHR and is displayed as increased sensitivity to direct pharmacologic bronchoconstrictor stimuli, such as inhaled histamine and methacholine (direct AHR), or to endogenous mediators released by activated airway cells such as mast cells (indirect AHR). Research in in vivo human models has shown that the disrupted airway epithelium plays an important role in driving inflammation that mediates indirect AHR in asthma through the release of cytokines such as thymic stromal lymphopoietin and IL-33. These cytokines upregulate type 2 cytokines promoting airway eosinophilia and induce the release of bronchoconstrictor mediators from mast cells such as histamine, prostaglandin D2, and cysteinyl leukotrienes. While bronchoconstriction is largely due to airway smooth muscle contraction, airway structural changes known as remodeling, likely mediated in part by epithelial-derived mediators, also lead to airflow obstruction and may enhance AHR. In this review, we outline the current knowledge of the role of the airway epithelium in AHR in asthma and its implications on the wider disease. Increased understanding of airway epithelial biology may contribute to better treatment options, particularly in precision medicine.

Effect of curcumin nanoparticles on proliferation and migration of mouse airway smooth muscle cells and airway inflammatory infiltration

Curcumin (CUR) possesses the capability to inhibit various inflammatory factors, exert anti-inflammatory effects, and alleviate asthma attacks; however, its hydrophobicity and instability significantly impede its clinical application. In this study, we synthesized CUR-loaded nanoparticles (CUR-NPs) and evaluated their impact on the proliferation, migration, and inflammatory infiltration of mouse airway smooth muscle cells (ASMCs), while investigating their underlying mechanisms. To achieve this objective, ASMCs were isolated from BALB/c mice and subjected to TGF-β1-induced cell proliferation and migration. Our findings demonstrate that CUR-NPs effectively regulate the release of CUR within cells with superior intracellular uptake compared to free CUR. The CCK-8 assay results indicate that the blank carrier does not exhibit any cytotoxic effects on cells, thus rendering the impact of the carrier itself negligible. The TGF-β1 group exhibited a significant increase in cell proliferation, whereas treatment with CUR-NPs significantly suppressed TGF-β1-induced cell proliferation. The findings from both the cell scratch assay and transwell assay demonstrated that TGF-β1 substantially enhanced cell migration, while CUR-NPs treatment effectively attenuated TGF-β1-induced cell migration. The Western blot analysis demonstrated a substantial increase in the expression levels of TGF-β1, p-STAT3, and CTGF in ASMCs following treatment with TGF-β1 when compared to the control group. Nevertheless, this effect was effectively counteracted upon administration of CUR-NPs. Furthermore, an asthma mouse model was successfully established and CUR-NPs were administered through tail vein injection. The serum levels of TGF-β1 and the expression levels of TGF-β1, p-STAT3, and CTGF proteins in the lung tissue of mice in the model group exhibited significant increases compared to those in the control group. However, CUR-NPs treatment effectively attenuated this change. Our research findings suggest that CUR-NPs possess inhibitory effects on ASMC proliferation, migration, and inflammatory infiltration by suppressing activation of the TGF-β1/p-STAT3/CTGF signaling pathway, thereby facilitating inhibition of airway remodeling.

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.

The role of epithelial cells in fibrosis: Mechanisms and treatment

Fibrosis is a pathological process that affects multiple organs and is considered one of the major causes of morbidity and mortality in multiple diseases, resulting in an enormous disease burden. Current studies have focused on fibroblasts and myofibroblasts, which directly lead to imbalance in generation and degradation of extracellular matrix (ECM). In recent years, an increasing number of studies have focused on the role of epithelial cells in fibrosis. In some cases, epithelial cells are first exposed to external physicochemical stimuli that may directly drive collagen accumulation in the mesenchyme. In other cases, the source of stimulation is mainly immune cells and some cytokines, and epithelial cells are similarly altered in the process. In this review, we will focus on the multiple dynamic alterations involved in epithelial cells after injury and during fibrogenesis, discuss the association among them, and summarize some therapies targeting changed epithelial cells. Especially, epithelial mesenchymal transition (EMT) is the key central step, which is closely linked to other biological behaviors. Meanwhile, we think studies on disruption of epithelial barrier, epithelial cell death and altered basal stem cell populations and stemness in fibrosis are not appreciated. We believe that therapies targeted epithelial cells can prevent the progress of fibrosis, but not reverse it. The epithelial cell targeting therapies will provide a wonderful preventive and delaying action.

Targeting Asthma Remission as the Next Therapeutic Step Toward Improving Disease Control

The long-term goal of asthma management is to achieve disease control, comprising the assessment of 2 main domains: (1) symptom control and (2) future risk of adverse outcomes. Decades of progress in asthma management have correlated with increasingly ambitious disease control targets. Moreover, the introduction of precision medicines, such as biologics, has further expanded the limits of what can be achieved in terms of disease control. It is now believed that clinical remission, a term rarely associated with asthma, may be an achievable treatment goal. An expert framework published in 2020 took the first step toward developing a commonly accepted definition of clinical remission in asthma. However, there remains a widespread discussion about the clinical parameters and thresholds that should be included in a standardized definition of clinical remission. This review aims to discuss on-treatment clinical remission as an aspirational outcome in asthma management, drawing on experiences from other chronic diseases where remission has long been a goal. We also highlight the integral role of shared decision-making between patients and health care professionals and the need for a common understanding of the individual patient journey to remission as foundational elements in reducing disease burden and improving outcomes for patients with asthma.

LINC00158 modulates the function of BEAS-2B cells via targeting BCL11B and ameliorates OVA-LPS-induced severe asthma in mice models

Persistent type (T) 2 airway inflammation plays an important role in the development of severe asthma. However, the molecular mechanisms leading to T2 severe asthma have yet to be fully clarified. Human normal lung epithelial cells (BEAS-2B cells) were transfected with LINC00158/BCL11B plasmid/small interfering RNA (siRNA). Levels of epithelial-mesenchymal transition (EMT)-related markers were measured using real-time qPCR (RT-qPCR) and western blot. A dual luciferase reporter assay was used to validate the targeting relationship between LINC00158 and BCL11B. The effects of LINC00158-lentivirus vector-mediated overexpression and dexamethasone on ovalbumin (OVA)/lipopolysaccharide (LPS)-induced severe asthma were investigated in mice in vivo. Our study showed that overexpression of LINC00158/BCL11B inhibited the levels of EMT-related proteins, apoptosis, and promoted the proliferation of BEAS-2B cells. BCL11B was a direct target of LINC00158. And LINC00158 targeted BCL11B to regulate EMT, apoptosis, and cell proliferation of BEAS-2B cells. Compared with severe asthma mice, LINC00158 overexpression alleviated OVA/LPS-induced airway hyperresponsiveness and airway inflammation, including reductions in T helper 2 cells factors in lung tissue and BALF, serum total- and OVA-specific IgE, inflammatory cell infiltration, and goblet cells hyperplasia. In addition, LINC00158 overexpression alleviated airway remodeling, including reduced plasma TGF-β1 and collagen fiber deposition, as well as suppression of EMT. Additionally, overexpression of LINC00158 enhanced the therapeutic effect of dexamethasone in severe asthmatic mice models. LINC00158 regulates BEAS-2B cell biological function by targeting BCL11B. LINC00158 ameliorates T2 severe asthma in vivo and provides new insights into the clinical treatment of severe asthma.

Recent Developments in the Role of Histone Acetylation in Asthma

BACKGROUND

Epigenetic modifications are known to mediate both beneficial and unfavorable effects of environmental exposures on the development and clinical course of asthma. On the molecular level, epigenetic mechanisms participate in multiple aspects of the emerging and ongoing asthma pathology.

SUMMARY

Studies performed in the last several years expand our knowledge on the role of histone acetylation, a classical epigenetic mark, in the regulation of (patho)physiological processes of diverse cells playing a central role in asthma, including those belonging to the immune system (e.g., CD4+ T cells, macrophages) and lung structure (e.g., airway epithelial cells, pulmonary fibroblasts). Those studies demonstrate a number of specific histone acetylation-associated mechanisms and pathways underlying pathological processes characteristic for asthma, as well as report their modification modalities.

KEY MESSAGES

Dietary modulation of histone acetylation levels in the immune system might protect against the development of asthma and other allergies. Interfering with the enzymes controlling the histone acetylation status of structural lung and (local) immune cells might provide future therapeutic options for asthmatics. Despite some methodological obstacles, analysis of the histone acetylation levels might improve asthma diagnostics.

Exosomes From IgE-Stimulated Mast Cells Aggravate Asthma-Mediated Atherosclerosis Through circRNA CDR1as-Mediated Endothelial Cell Dysfunction in Mice

BACKGROUND

IgE has been known for mediating endothelial cell dysfunction and mast cell (MC) activation to fuel asthma-aggravated high-fat diet-induced atherosclerosis. However, it remains unclear for the mechanism of asthma-mediated atherosclerosis, especially the potential involvement of IgE in the exacerbation of asthma-mediated atherosclerosis with a standard laboratory diet, and the cross talk between endothelial cells and MCs.

METHODS

Asthma-mediated atherosclerosis mice models under a standard laboratory diet and FcεR1 knock-out mice were used to determine the role of IgE-FcεR1 signaling in asthma-mediated atherosclerosis, which was assessed by Oil Red O staining and immunohistochemistry. Various in vitro assays including nanoparticle tracking analysis and transmission electron microscopy were used to evaluate exosome characteristics. Immunofluorescence and fluorescent in situ hybridization approaches were used to evaluate the effect and mechanism of MC-secreted exosomes encapsulated circular RNA CDR1as (cerebellar degeneration-related 1 antisense) on endothelial cells in vivo and in vitro. Finally, cohort studies examined the plasma CDR1as levels in patients with atherosclerosis with or without allergies.

RESULTS

Asthma mice with a standard laboratory diet showed increased atherosclerotic lesions and inflammatory infiltration depending on IgE-FcεR1 signal. FcεR1 knockout mice and blockage of IgE-FcεR1 signaling with IgE monoclonal antibody, omalizumab, all significantly alleviated asthma-mediated atherosclerosis and vascular inflammatory remodeling. Anti-inflammation with dexamethasone and stabilization of MC with cromolyn partially alleviated atherosclerotic lesions and mitigated the inflammatory infiltration in arteries. Mechanistically, IgE stimulation upregulates MC CDR1as expression in exosomes and upregulates the endothelial cell adhesive factors VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1) via the CDR1as-FUS (fused in sarcoma)-phos-p65 axis. Knockdown of CDR1as in vivo significantly decreased the endothelial adhesion function and mitigated asthma-mediated atherosclerosis. Furthermore, a cohort study indicated higher plasma CDR1as levels in patients with atherosclerosis with allergies than in patients with atherosclerosis and healthy controls.

CONCLUSIONS

Exosomes from IgE-stimulated MCs aggravated atherosclerosis through circular RNA CDR1as-mediated endothelial dysfunction, providing a novel insight into asthma-mediated atherosclerosis and potential diagnostic and therapeutic targets.

The implication of infection with respiratory syncytial virus in pediatric recurrent wheezing and asthma: knowledge expanded post-COVID-19 era

BACKGROUND

Respiratory syncytial virus (RSV) infection has been identified to serve as the primary cause of acute lower respiratory infectious diseases in children under the age of one and a significant risk factor for the emergence and development of pediatric recurrent wheezing and asthma, though the exact mechanism is still unknown.

METHODS AND RESULTS

In this study, we discuss the key routes that lead to recurrent wheezing and bronchial asthma following RSV infection. It is interesting to note that following the coronavirus disease 2019 (COVID-19) epidemic, the prevalence of RSV changes significantly. This presents us with a rare opportunity to better understand the associated mechanism for RSV infection, its effects on the respiratory system, and the immunological response to RSV following the COVID-19 epidemic. To better understand the associated mechanisms in the occurrence and progression of pediatric asthma, we thoroughly described how the RSV infection directly destroys the physical barrier of airway epithelial tissue, promotes inflammatory responses, enhances airway hyper-responsiveness, and ultimately causes the airway remodeling. More critically, extensive discussion was also conducted regarding the potential impact of RSV infection on host pulmonary immune response.

CONCLUSION

In conclusion, this study offers a comprehensive perspective to better understand how the RSV infection interacts in the control of the host's pulmonary immune system, causing recurrent wheezing and the development of asthma, and it sheds fresh light on potential avenues for pharmaceutical therapy in the future.

The great potential of polysaccharides from natural resources in the treatment of asthma: A review

Despite significant progress in diagnosis and treatment, asthma remains a serious public health challenge. The conventional therapeutic drugs for asthma often have side effects and unsatisfactory clinical efficacy. Therefore, it is very urgent to develop new drugs to overcome the shortcomings of conventional drugs. Natural polysaccharides provide enormous resources for the development of drugs or health products, and they are receiving a lot of attention from scientists around the world due to their safety, effective anti-inflammatory and immune regulatory properties. Increasing evidence shows that polysaccharides have favorable biological activities in the respiratory disease, including asthma. This review provides an overview of primary literature on the recent advances of polysaccharides from natural resources in the treatment of asthma. The mechanisms and practicability of polysaccharides, including polysaccharides from plants, fungus, bacteria, alga, animals and others are reviewed. Finally, the further research of polysaccharides in the treatment of asthma are discussed. This review can provide a basis for further study of polysaccharides in the treatment of asthma and provides guidance for the development and clinical application of novel asthma treatment drugs.

PM2.5 activates IL-17 signaling pathway in human nasal mucosa-derived fibroblasts

Fine particulate matter (PM2.5) represents a prevalent environmental pollutant in the atmosphere, capable of exerting deleterious effects on human health. Numerous studies have indicated a correlation between PM2.5 exposure and the development of chronic upper airway inflammatory diseases. The objective of this study was to investigate the impact of PM2.5 on the transcriptome of fibroblasts derived from nasal mucosa. Initially, nasal mucosa-derived fibroblasts were isolated, cultured, and subsequently stimulated with PM2.5 (100 μg/mL) or an equivalent volume of normal culture medium for a duration of 24 h. Following this, total RNA from these cells was extracted, purified, and subjected to sequencing using next-generation RNA sequencing technology. Differentially expressed genes (DEGs) were then identified and utilized for functional enrichment analysis. A protein-protein interaction (PPI) network of DEGs was constructed, and validation of key genes and proteins was carried out using quantitative real-time PCR and ELISA methods. Results revealed 426 DEGs, comprising 276 up-regulated genes and 150 down-regulated genes in nasal mucosa-derived fibroblasts treated with PM2.5 compared to control cells. Functional enrichment analysis indicated that DEGs were predominantly associated with inflammation-related pathways, including the IL-17 signaling pathway. In alignment with this, PPI analysis highlighted that hub genes were primarily involved in the regulation of the IL-17 signaling pathway. Subsequent validation through quantitative real-time PCR and ELISA confirmed significant alterations in the relative expressions of IL-17 signaling pathway-related genes and concentrations of IL-17 signaling pathway related proteins in nasal mucosa-derived fibroblasts treated with PM2.5 compared to control cells. In conclusion, PM2.5 intervention substantially altered the transcriptome of nasal mucosa-derived fibroblasts. Furthermore, PM2.5 has the potential to exacerbate the inflammatory responses of these fibroblasts by modulating the expression of key genes in the IL-17 signaling pathway.

Research trends on airway remodeling: A bibliometrics analysis

Background

Airway remodeling is an essential pathological basis of respiratory diseases such as asthma and COPD, which is significantly related to pulmonary function and clinical symptoms. And pulmonary disease can be improved by regulating airway remodeling. This study aimed to establish a knowledge map of airway remodeling to clarify current research hotspots and future research trends.

Methods

A comprehensive search was performed to analyze all relevant articles on airway remodeling using the Web of Science Core Collection Database from January 01, 2004 to June 03, 2023.2 reviewers screened the retrieved literature. Besides, the CiteSpace (6.2. R3) and VOSviewer (1.6.19) were utilized to visualize the research focus and trend regarding the effect of airway remodeling.

Results

A total of 4077 articles about airway remodeling were retrieved. The United States is the country with the most published literature, underscoring the country's role in airway remodeling. In recent years, China has been the country with the fastest growth in the number of published literature, suggesting that China will play a more critical role in airway remodeling in the future. From the perspective of co-operation among countries, European co-operation was closer than Asian co-operation. The co-citation analysis showed that 98,313 citations were recorded in 3594 articles, and 25 clusters could be realized. In recent years, Burst detection shows that oxidative stress and epithelial-mesenchymal transition are hot words.

Conclusions

Based on the bibliometric analysis of airway remodeling studies in the past 20 years, a multi-level knowledge structure map was drawn, it mainly includes countries, institutions, research fields, authors, journals, keywords and so on. The research directions represented by obstructive airway disease, PDGF-BB treatment of airway smooth muscle, allergen-induced airway remodeling, extracellular matrix, and non-coding RNA are the research hotspots in the field of airway remodeling. While the risk factors for airway remodeling, the application of new noninvasively assessing tools, biomarkers as well as The molecular mechanism represented by EMT and autophagy had been frontiers in recent years.

IgE in allergy: It takes two

A type 2 memory B cell subset is poised to differentiate into IgE-producing plasma cells in individuals with allergies (Ota et al. and Koenig et al.).

Possible role of HE4 level elevation in the pathogenesis of TH2-high asthma

OBJECTIVES

As a heterogeneous disease, asthma is characterized by airway hyperresponsiveness, airway inflammation, and airway mucus hypersecretion. According to the pathological changes, symptoms, preventive and treatment methods, asthma can be divided into TH2-high and TH2-low asthma. We show that the expression of the tumor biomarker human epididymis protein 4 (HE4) was significantly increased in TH2-high asthma group, while there was no marked difference in its expression between TH2-low asthma and healthy control groups. HE4 levels were significantly increased in plasma, induced sputum, and alveolar lavage fluid (BALF) samples and airway epithelial cells from TH2-high asthma group, showing that HE4 has a possible role in the pathogenesis of TH2-high asthma.

METHODS

Using RT-qPCR, ELISA, Western blot (WB), and immunohistochemistry, we assessed differences in HE4 expression in plasma, induced sputum, BALF, and airway epithelial cells among patients with the TH2-related asthma subtypes and healthy controls. To explore the role of HE4 in TH2-high asthma, we conducted a correlation analysis between HE4 levels in plasma, induced sputum, BALF, and airway epithelial cells and multiple indicators of airway eosinophilic inflammation, airway mucus secretion, and airway remodeling.

CONCLUSION

We found for the first time that HE4 was differentially expressed in the TH2-related asthma subtypes. In TH2-high asthma, HE4 levels were markedly elevated in airway epithelial cells, plasma, induced sputum, and BALF. HE4 may play an important role in various pathogenic mechanisms of asthma, such as airway eosinophilic inflammation, airway mucus secretion, and airway remodeling. HE4 in plasma may be a clinically biomarker for differentiating TH2-related asthma subtypes.

Features of severe asthma response to anti-IL5/IL5r therapies: identikit of clinical remission

Introduction

Clinical remission (CliR) achievement has been recognized as a new potential outcome in severe asthma. Nevertheless, we still lack a detailed profile of what features could better identify patients undergoing clinical remission. In this study, we aim to address this issue, tracing a possible identikit of patients fulfilling remission criteria.

Methods

We enrolled 266 patients with severe eosinophilic asthma (SEA) treated with a 12-month course of anti-IL5/IL5 receptor (IL5r) monoclonal antibodies. Patients with no exacerbation, OCS withdrawal, ACT ≥ 20 and FEV1 ≥ 80% after 1 year of biologic treatment were classified as in clinical remission.

Results

30.5% of the enrolled patients achieved remission after biologic administration. CliR group showed a lower number of baseline asthma exacerbations and better lung function parameters, with a trend for higher ACT scores and a less frequent history of a positive skin prick test. CliR achievement was unlikely in presence of a higher BMI, a positive skin prick test, an increased number of asthma exacerbations before biologic treatment, anti-muscarinic administration, and a previous diagnosis of EGPA, bronchiectasis or osteoporosis. In contrast, a better lung function, an increased blood eosinophilic count, the presence of chronic rhinosinusitis with nasal polyps and a more frequent use of reliever therapy predicts remission development. Changes in exacerbations number, OCS use, ACT scores and FEV1% between remittent and non-remittent patients arise at specific follow up timepoints and are positively associated with CliR achievement.

Discussion

anti-IL5/IL5r biologics can induce CliR in a proportion of patients with SEA. Patients achieving remission demonstrate specific clinical, functional and inflammatory features, as well as a specific moment of improvement in all the CliR items.

Long non-coding RNA (LncRNA) non-coding RNA activated by DNA damage (NORAD) knockdown alleviates airway remodeling in asthma via regulating miR-410-3p/RCC2 and inhibiting Wnt/β-catenin pathway

Background

Asthma is a chronic inflammatory disorder with high prevalence in childhood. Airway remodeling, an important structural change of the airways, is resulted from epithelial-mesenchymal transition. Long non-coding RNA non-coding RNA activated by DNA damage (NORAD) has been found to promote epithelial-mesenchymal transition in multiple cancers. This study aimed to analyze the role of NORAD in asthma, mainly focusing on epithelial-mesenchymal transition-mediated airway remodeling, and further explored the NORAD-miRNA-mRNA network.

Methods

NORAD expression was analyzed in transforming growth factor-β1-induced BEAS-2B human bronchial epithelial cells and ovalbumin-challenged asthmatic mice. The influences of NORAD on the epithelial-mesenchymal transition characteristics and Wnt/β-catenin pathway activation were analyzed in vitro. The interactions between NORAD and miR-410-3p as well as miR-410-3p and regulator of chromosome condensation 2 were detected by dual-luciferase reporter assay and RNA pull-down assay. Rescue experiments using miR-410-3p antagonist and chromosome condensation 2 overexpression were used to confirm the mechanism of NORAD. Additionally, the role and mechanism of NORAD were further evaluated in asthmatic mice.

Results

NORAD expression was elevated in both asthmatic models. Knockdown of NORAD impeded spindle-like morphology changes, elevated E-cadherin expression, decreased N-cadherin expression, suppressed cell migration, and inactivated the Wnt/β-catenin pathway in transforming growth factor-β1-stimulated BEAS-2B cells. NORAD acted as a sponge of miR-410-3p to regulate chromosome condensation 2 expression. Rescue assays demonstrated that silencing of NORAD ameliorated transforming growth factor-β1-induced EMT via miR-410-3p/chromosome condensation 2/Wnt/β-catenin axis. In vivo, knockdown of NORAD led to the reduction of inflammatory cell infiltration and collagen deposition, suppression of IL-4, IL-13, transforming growth factor-β1 and immunoglobulin E production, decreasing of N-cadherin, chromosome condensation 2, β-catenin and c-Myc expression, but increasing of E-cadherin and miR-410-3p expression.

Conclusions

Silencing of NORAD alleviated epithelial-mesenchymal transition-mediated airway remodeling in asthma via mediating miR-410-3p/chromosome condensation 2/Wnt/β-catenin pathway.

CD147 induces asthmatic airway remodeling and activation of circulating fibrocytes in a mouse model of asthma

BACKGROUND

Airway remodeling is a poorly reversible feature of asthma which lacks effective therapeutic interventions. CD147 can regulate extracellular matrix (ECM) remodeling and tissue fibrosis, and participate in the pathogenesis of asthma. In this study, the role of CD147 in airway remodeling and activation of circulating fibrocytes was investigated in asthmatic mice.

METHODS

Asthmatic mouse model was established by sensitizing and challenging mice with ovalbumin (OVA), and treated with anti-CD147 or Isotype antibody. The number of eosinophils in bronchoalveolar lavage fluid (BALF) was examined by microscope, and the levels of interleukin-4 (IL-4), IL-5 and IL-13 in BALF were detected by enzyme-linked immunosorbent assay (ELISA). The number of CD45+ and collagen I (COL-I)+ circulating fibrocytes in BALF was detected by flow cytometry. Lung tissue sections were respectively stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS) or Masson trichrome staining, or used for immunohistochemistry of CD31 and immunohistofluorescence of α-smooth muscle actin (α-SMA), CD45 and COL-I. The protein expression of α-SMA, vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), Fibronectin, and COL-I was determined by western blotting.

RESULTS

Anti-CD147 treatment significantly reduced the number of eosinophils and the levels of IL-4, IL-13, and IL-5 in BALF, and repressed airway inflammatory infiltration and airway wall thickening in asthmatic mice. Anti-CD147 treatment also reduced airway goblet cell metaplasia, collagen deposition, and angiogenesis in asthmatic mice, accompanied by inhibition of VEGF and α-SMA expression. The number of CD45+COL-I+ circulating fibrocytes was increased in BALF and lung tissues of OVA-induced asthmatic mice, but was decreased by anti-CD147 treatment. In addition, anti-CD147 treatment also reduced the protein expression of COL-I, fibronectin, and TGF-β1 in lung tissues of asthmatic mice.

CONCLUSION

OVA-triggered airway inflammation and airway remodeling in asthmatic mice can be repressed by anti-CD147 treatment, along with inhibiting the accumulation and activation of circulating fibrocytes.

"Patient remodeling" as a consequence of uncontrolled and prolonged OCS use in severe asthma: how biologic therapy can reverse a dangerous trend

INTRODUCTION

Asthma is a chronic inflammatory disease that can lead to airways remodeling. Despite their well-known side-effects, oral corticosteroids (OCS) continue to be used to reduce exacerbations and control asthma symptoms in many patients.

CASE STUDY

We describe two cases of uncontrolled severe asthma characterized by systemic clinical consequences of prolonged OCS use, such as diabetes, weight gain, and osteoporosis.

RESULTS

Both patients were treated with Dupilumab. During follow-up both patients showed an improvement in asthma control and were able to gradually taper the OCS dose, thus reducing the clinical burden associated with hypercortisolism.

CONCLUSION

Dupilumab was able to control both the inflammatory-induced "airway remodeling" as well as the OCS-induced "patient remodeling".

Sputum Transcriptomics Reveals FCN1+ Macrophage Activation in Mild Eosinophilic Asthma Compared to Non-Asthmatic Eosinophilic Bronchitis

PURPOSE

Eosinophilic asthma (EA) and non-asthmatic eosinophilic bronchitis (EB) share similar eosinophilic airway inflammation. Unlike EA, EB did not present airway hyperresponsiveness or airflow obstruction. We aimed to compare the mechanism underlying the different manifestations between EA and EB via sputum transcriptomics analysis.

METHODS

Induced-sputum cells from newly physician-diagnosed EA, EB patients, and healthy controls (HCs) were collected for RNA sequencing.

RESULTS

Bulk RNA sequencing was performed using sputum cells from patients with EA (n = 18), EB (n = 15) and HCs (n = 28). Principal component analysis revealed similar gene expression patterns in EA and EB. The most differentially expressed genes in EB compared with HC were also shared by EA, including IL4, IL5 IL13, CLC, CPA3, and DNASE1L3. However, gene set enrichment analysis showed that the signatures regulating macrophage activation were enriched in EA compared to EB. Sputum cells were profiled using single-cell RNA sequencing. FABP4+ macrophages, SPP1+ macrophages, FCN1+ macrophages, dendritic cells, T cells, B cells, mast cells, and epithelial cells were identified based on gene expression profiling. Analysis of cell-cell communication revealed that interactions between FCN1+ macrophages and other cells were higher in EA than in EB. A wealth of transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) interactions between FCN1+ macrophages and other cells have been shown in EA. The gene expression levels of EREG, TGFBI, and VEGFA in FCN1+ macrophages of EA were significantly higher than those of EB. Furthermore, signatures associated with the response to TGF-β, cellular response to VEGF stimulus and developmental cell growth were enriched in FCN1+ macrophages of EA compared to those of EB.

CONCLUSIONS

FCN1+ macrophage activation associated with airway remodeling processes was upregulated in EA compared to that in EB, which may contribute to airway hyperresponsiveness and airflow obstruction.

Comparison of Long-term Response and Remission to Omalizumab and Anti-IL-5/IL-5R Using Different Criteria in a Real-life Cohort of Severe Asthma Patients

BACKGROUND

Evaluation of biologic therapy response is vital to monitor its effectiveness. Authors have proposed various response criteria including good responder, super-responder, non-responder, and clinical remission.

OBJECTIVES

To ascertain the prevalence of response and clinical remission after long-term treatment (>6 months) of anti-IgE and anti-IL-5/IL-5Rα biologics, compare these results with existing criteria, and identify predictors for non-responders and clinical remission.

METHODS

A multicenter, real-life study involving severe asthma patients in Spain. Various outcomes were assessed to gauge response and clinical remission against established criteria.

RESULTS

The study included 429 patients, 209 (48.7%) omalizumab, 112 (26.1%) mepolizumab, 19 (4.4%) reslizumab and 89 (20.7%) benralizumab, with a mean treatment duration of 55.3±38.8 months. In the final year of treatment, 218 (50.8%) were super-responders, 173 (40.3%) responders, 38 (8.9%) non-responders, and clinical remission in 116 (27%), without differences among biologics. The short-term non-responders (<6 months) were 25/545 (4.6%). Substantial variations in response and clinical remission were observed when applying different published criteria. Predictors of non-response included higher BMI (OR:1.14; 95% CI:1.06-1.23; p<0.001), admissions at ICU (2.69; 1.30-5.56; p=0.01), high count of SAE (1.21; 1.03-1.42; p=0.02) before biologic treatment. High FEV1% (0.96; 0.95-0.98; p<0.001), a high ACT score (0.93; 0.88-0.99; p=0.01) before biologic treatment or NSAID-ERD (0.52; 0.29-0.91; p=0.02) showed strong associations with achieving clinical remission.

CONCLUSION

A substantial proportion of severe asthma patients treated long-term with omalizumab or anti-IL5/IL-5Rα achieved a good response. Differences in response criteria highlight the need for harmonization in defining response and clinical remission in biologic therapy to enable meaningful cross-study comparisons.

Cysteine and glycine-rich protein 2 retards platelet-derived growth factor-BB-evoked phenotypic transition of airway smooth muscle cells by decreasing YAP/TAZ activity

Cysteine and glycine-rich protein 2 (Csrp2) has emerged as a key factor in controlling the phenotypic modulation of smooth muscle cells. The phenotypic transition of airway smooth muscle cells (ASMCs) is a pivotal step in developing airway remodeling during the onset of asthma. However, whether Csrp2 mediates the phenotypic transition of ASMCs in airway remodeling during asthma onset is undetermined. This work aimed to address the link between Csrp2 and the phenotypic transition of ASMCs evoked by platelet-derived growth factor (PDGF)-BB in vitro. The overexpression or silencing of Csrp2 in ASMCs was achieved through adenovirus-mediated gene transfer. The expression of mRNA was measured by quantitative real-time-PCR. Protein levels were determined through Western blot analysis. Cell proliferation was detected by EdU assay and Calcein AM assays. Cell cycle distribution was assessed via fluorescence-activated cell sorting assay. Cell migration was evaluated using the scratch-wound assay. The transcriptional activity of Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) was measured using the luciferase reporter assay. A decline in Csrp2 level occurred in PDGF-BB-stimulated ASMCs. Increasing Csrp2 expression repressed the PDGF-BB-evoked proliferation and migration of ASMCs. Moreover, increasing Csrp2 expression impeded the phenotypic change of PDGF-BB-stimulated ASMCs from a contractile phenotype into a synthetic/proliferative phenotype. On the contrary, the opposite effects were observed in Csrp2-silenced ASMCs. The activity of YAP/TAZ was elevated in PDGF-BB-stimulated ASMCs, which was weakened by Csrp2 overexpression or enhanced by Csrp2 silencing. The YAP/TAZ activator could reverse Csrp2-overexpression-mediated suppression of the PDGF-BB-evoked phenotypic switching of ASMCs, while the YAP/TAZ suppressor could dimmish Csrp2-silencing-mediated enhancement on PDGF-BB-evoked phenotypic switching of ASMCs. In summary, Csrp2 serves as a determinant for the phenotypic switching of ASMCs. Increasing Csrp2 is able to impede PDGF-BB-evoked phenotypic change of ASMCs from a synthetic phenotype into a synthetic/proliferative phenotype through the effects on YAP/TAZ. This work implies that Csrp2 may be a key player in airway remodeling during the onset of asthma.