Research advances in airway remodeling in asthma: a narrative review

Evaluation of the influenza vaccine protection in the house dust mite-induced chronic allergic asthma mice model and the evaluation of squalene oil in water emulsion as an adjuvant candidate

BACKGROUND

Despite the importance of influenza vaccination in asthma patients, the efficacy of this vaccine in asthma has not been well elucidated. We aimed to compare the efficacy of an influenza vaccine of the asthmatic and control mice. We also evaluated the efficacy of AddaVax™ as an adjuvant candidate, which is equivalent to the MF59 influenza vaccine adjuvant in the elderly.

METHOD

House dust mite extracts were intranasally injected into six-week-old female BALB/c mice to induce chronic allergic asthma. Antibody responses after split-inactivated A/Puerto Rico/8/34 H1N1 influenza vaccination with or without AddaVax™ adjuvant were measured using ELISA. Homologous viral protection was determined by measuring the survival rate, lung inflammation level, and lung virus titer after challenge with the human influenza virus strain A/Puerto Rico/8/1934 H1N1. Antigen-specific T cell responses were determined using flow cytometry.

RESULT

The chronic asthma mice immunized with split-inactivated A/Puerto Rico/8/34 H1N1 influenza vaccine showed significant weight loss and higher lung viral load after homologous influenza infection than naïve vaccinated mice. Antigen-specific IgG, IgG1, and IgG2a production did not differ between the naïve and asthma mice. However, serum HI titer was lower in asthma-vaccinated mice after infection. The application of AddaVax™ to a vaccine for mice with asthma enhanced the efficacy of homologous antiviral protection but elicited eosinophil infiltration in the lungs after homologous influenza virus infection.

CONCLUSION

The immune response after split inactivated A/PR8 vaccine differed between asthma and naïve mice, particularly in terms of antibody activity and T cell populations. This study enhances our understanding of how asthma status may influence the effectiveness of influenza vaccine and offers insights into the AddaVax™-induced eosinophilic inflammation, guiding the development of virus vaccine strategies for both healthy individuals and asthma patients.

Store-operated Ca2+ entry contributes to the ASM phenotype transition in asthma

AIM OF THE STUDY

Phenotype modulation of airway smooth muscle cells (ASMC), characterized by a shift toward a more proliferative and synthetic phenotype from contractile cells, plays a crucial role in airway remodeling in asthma. STIM1 and Orai1, key components of store-operated Ca2+ entry (SOCE), have been demonstrated to enhance ASMC proliferation and migration. This study investigated the impact of STIM1/Orai1-mediated SOCE on ASMC phenotype transition and extracellular matrix (ECM) deposition in asthma.

MATERIALS AND METHODS

The ASMCs were treated with PDGF-BB and SOCE inhibitors. Immunocytochemistry staining, enzyme-linked immunosorbent assay, and western blot assay were employed to detect the ASMC's proliferation as well as the expressions of contractile proteins, inflammatory cytokines and ECM. Moreover, the effect of SOCE repression in ECM deposition were evaluated in an asthmatic mouse model.

RESULTS

ASMCs from airways of mice were treated with PDGF-BB to induce the 'proliferative/synthetic' phenotype. We observed elevated expressions of STIM1 and Orai1 in phenotype-switched ASMCs, along with enhanced SOCE. SKF-96365 and RO2959, which target of STIM1/Orai1, could significantly inhibit SOCE activation in ASMCs. Moreover, these SOCE inhibitors mitigated the elevated proliferation rate, decreased the secretion of inflammatory cytokines and restored the reduced levels of contractile proteins in phenotype-switched ASMCs induced by PDGF-BB. Furthermore, we observed that PDGF-BB-induced 'proliferative/synthetic' ASMCs exhibited increased production of ECM components, including collagen I and fibronectin, as well as metalloproteinases (MMPs) such as MMP2 and MMP9, all of which were effectively inhibited by SKF-96365 and RO2959. In vivo experiments also demonstrated that SOCE inhibitors decreased ECM deposition and MMPs production in the asthmatic mouse model.

CONCLUSIONS

These findings underscored the significant role of STIM1/Orai1-mediated SOCE in ASMC phenotype modulation and its impact on the excessive ECM deposition driven by ASMCs. Thus, our findings suggest that STIM1/Orai1-mediated SOCE may contribute to airway remodeling in asthma.

Computed tomography-based measurements associated with rapid lung function decline in severe asthma

BACKGROUND

Patients with severe asthma are susceptible to lung function decline (LFD), but biomarkers that reliably predict an accelerated LFD have not been fully recognized.

OBJECTIVE

To identify variables associated with previous LFD occurrences in patients with severe asthma by exploring the computed tomography (CT) imaging features within predefined LFD groups.

METHODS

We obtained inspiratory and expiratory CT images of 102 patients with severe asthma and derived 2 airway structural parameters (wall thickness [WT] and hydraulic diameter) and 2 parenchymal variables (functional small airway disease and emphysema). We retrospectively calculated the annual changes in forced expiratory volume in 1 second and grouped participants by their values determined. The 4-imaging metrics, along with levels of several biomarkers, were compared among the LFD groups.

RESULTS

Patients with severe asthma with enhanced LFD exhibited significantly lower WT and smaller hydraulic diameter compared with those with minimal change or slight decline in lung function, after an adjustment of smoking status. Conversely, CT-based percentages of emphysema and functional small airway disease did not significantly differ according to LFD. Furthermore, fractional exhaled nitric oxide (FeNO) level and the blood matrix metalloproteinase-9/TIMP metallopeptidase inhibitor 1 ratio were significantly higher in patients with severe asthma with enhanced LFD compared with those in the others.

CONCLUSION

Lower WT on CT scans with increased FeNO that may represent increased airway inflammation significantly correlated with enhanced LFD in patients with severe asthma. Consequently, active management plans may help to attenuate LFD for patients with severe asthma with lower WT and high FeNO.

Airborne fine particulate matter exposure induces transcriptomic alterations resembling asthmatic signatures: insights from integrated omics analysis

Fine particulate matter (PM2.5), an atmospheric pollutant that settles deep in the respiratory tract, is highly harmful to human health. Despite its well-known impact on lung function and its ability to exacerbate asthma, the molecular basis of this effect is not fully understood. This integrated transcriptomic and epigenomic data analysis from publicly available datasets aimed to determine the impact of PM2.5 exposure and its association with asthma in human airway epithelial cells. Differential gene expression and binding analyses identified 349 common differentially expressed genes and genes associated with differentially enriched H3K27ac regions in both conditions. Co-expression network analysis revealed three preserved modules (Protein Folding, Cell Migration, and Hypoxia Response) significantly correlated with PM2.5 exposure and preserved in asthma networks. Pathways dysregulated in both conditions included epithelial function, hypoxia response, interleukin-17 and TNF signaling, and immune/inflammatory processes. Hub genes like TGFB2, EFNA5, and PFKFB3 were implicated in airway remodeling, cell migration, and hypoxia-induced glycolysis. These findings elucidate common altered expression patterns and processes between PM2.5 exposure and asthma, helping to understand their molecular connection. This provides guidance for future research to utilize them as potential biomarkers or therapeutic targets and generates evidence supporting the need for implementing effective air quality management strategies.

Lung stem cells and respiratory epithelial chimerism in transplantation

Stem cells are capable of self-renewal and differentiation into specialised types. They range from totipotent cells to multipotent or somatic stem cells and ultimately to unipotent cells. Some adult multipotent stem cells can have the potential to regenerate and colonise diverse tissues. The respiratory airways and lung mucosa, exposed to ambient air, perform vital roles for all human tissues and organs. They serve as barriers against airborne threats and are essential for tissue oxygenation. Despite low steady-state turnover, lungs are vulnerable to injuries and diseases from environmental exposure. Lung stem cells are crucial due to their regenerative potential and ability to replace damaged cells. Lung repair with extrapulmonary stem cells can occur, leading to the coexistence of respiratory cells with different genetic origins, a phenomenon known as airway epithelial chimerism. The impact of such chimerism in lung repair and disease is actively studied. This review explores different stem cell types, focusing on pulmonary stem cells. It discusses airway epithelium models derived from stem cells for studying lung diseases and examines lung chimerism, particularly in lung transplantation and haematopoietic stem cell transplantation, highlighting its significance in understanding tissue repair and chimerism-mediated repair processes in lung pathology.

Kiss1 receptor knockout exacerbates airway hyperresponsiveness and remodeling in a mouse model of allergic asthma

BACKGROUND

In asthma, sex-steroids signaling is recognized as a critical regulator of disease pathophysiology. However, the paradoxical role of sex-steroids, especially estrogen, suggests that an upstream mechanism or even independent of estrogen plays an important role in regulating asthma pathophysiology. In this context, in our previous studies, we explored kisspeptin (Kp) and its receptor Kiss1R's signaling in regulating human airway smooth muscle cell remodeling in vitro and airway hyperresponsiveness (AHR) in vivo in a mouse (wild-type, WT) model of asthma. In this study, we evaluated the effect of endogenous Kp in regulating AHR and remodeling using Kiss1R knockout (Kiss1R-/-) mice.

METHODS

C57BL/6J WT (Kiss1R+/+) and Kiss1R-/- mice, both male and female, were intranasally challenged with mixed-allergen (MA) and/or phosphate-buffered saline (PBS). We used flexiVent analysis to assess airway resistance (Rrs), elastance (Ers), and compliance (Crs). Following this, broncho-alveolar lavage (BAL) was performed for differential leukocyte count (DLC) and cytokine analysis. Histology staining was performed using hematoxylin and eosin (H&E) for morphological analysis and Masson's Trichrome (MT) for collagen deposition. Additionally, lung sections were processed for immunofluorescence (IF) of Ki-67, α-smooth muscle actin (α-SMA), and tenascin-c.

RESULTS

Interestingly, the loss of Kiss1R exacerbated lung function and airway contractility in mice challenged with MA, with more profound effects in Kiss1R-/- female mice. MA-challenged Kiss1R-/- mice showed a significant increase in immune cell infiltration and proinflammatory cytokine levels. Importantly, the loss of Kiss1R aggravated Th2/Th17 biased cytokines in MA-challenged mice. Furthermore, histology of lung sections from Kiss1R-/- mice showed increased collagen deposition on airway walls and mucin production in airway cells compared to Kiss1R+/+ mice. In addition, immunofluorescence analysis showed loss of Kiss1R significantly aggravated airway remodeling and subsequently AHR.

CONCLUSIONS

These findings demonstrate the importance of inherent Kiss1R signaling in regulating airway inflammation, AHR, and remodeling in the pathophysiology of asthma.

Mitigation of allergic asthma in mice: A compound mixture comprising luteolin, arbutin, and marmesin from Gerbera Piloselloides Herba by suppression of PI3K/Akt pathway

Background

Gerberae Piloselloidis Herba (GPH) exhibits notable efficacy in alleviating allergic asthma. Previous studies in our research have identified a mixture of luteolin, arbutin, and marmesin as effective components of GPH in treating allergic asthma. However, the underlying mechanism remains unclear. This study aims to elucidate the molecular mechanism of these active components.

Method

Using an ovalbumin (OVA)-induced allergic asthma mouse model, various treatment groups were administered, including GPH, the active component mixture (termed "Mixture") containing luteolin, arbutin, and marmesin, and a positive drug (dexamethasone, DEX). Relevant indices were assessed, including behavioral characteristics, inflammatory cell counts, cytokine levels, histopathological examination of lung tissue, apoptosis, and expression of key proteins such as Caspase-3, Bax, Bcl-2, PI3K, p-PI3K, Akt, and p-Akt. The effect of the Mixture on the PI3K/Akt signaling pathway was further verified using the PI3K inhibitor LY294002.

Results

The Mixture significantly alleviated asthma symptoms, decreased IgE levels, cytokine levels (IL-4, IL-5, IL-13 and TNF-α), and the number of inflammatory cells in serum or bronchoalveolar lavage fluid (BALF), leading to the alleviation of lung pathological lesions. Additionally, the Mixture reduced the expression of Bax and Caspase-3 while increasing Bcl-2 expression, resulting in mitigated apoptosis in lung tissue. Furthermore, there appeared a decrease in the levels of PI3K and p-PI3K, as well as the ratio of p-Akt to Akt in the Mixture group, indicating the suppression of PI3K and Akt phosphorylation. Interestingly, the effects of the Mixture were comparable to those of GPH, LY294002, or the combination of LY294002 with the Mixture.

Conclusion

The study confirms that the Mixture containing luteolin, arbutin, and marmesin indeed alleviates allergic asthma induced by OVA in mice by suppressing the PI3K/Akt signaling pathway. These findings highlight the potential of the GPH-derived Mixture as a novel therapeutic for the treatment of allergic asthma.

[Effects of inhibition of Rho/ROCK pathway on proliferation and migration of airway smooth muscle cells and related mechanisms]

OBJECTIVES

To investigate the effects and molecular mechanisms of inhibition of the Ras homolog gene (Rho)/Rho-associated coiled-coil forming protein kinase (ROCK) pathway on the proliferation and migration of airway smooth muscle cells involving myocardin (MYOCD).

METHODS

Human airway smooth muscle cells were infected with the adenoviral vector Ad-ZsGreen-shRNA-hROCK1 in vitro. The cells were randomly divided into four groups: ROCK1 gene silencing control (shNC) group, shNC + arachidonic acid (AA, Rho/ROCK pathway activator) group, ROCK1 gene silencing (shROCK1) group, and shROCK1 + AA group (n=3 each). Quantitative real-time polymerase chain reaction and Western blot were used to detect the expression levels of ROCK1 and MYOCD mRNA and protein. ELISA was employed to measure the levels of globular actin and filamentous actin, while immunofluorescent staining and scratch assays were utilized to assess cell proliferation and migration.

RESULTS

Compared to the shNC + AA group, the shROCK1 + AA group exhibited decreased levels of ROCK1 and MYOCD mRNA and protein expression, reduced expression levels of globular actin and filamentous actin, and diminished cell proliferation and migration capabilities (P<0.05).

CONCLUSIONS

Inhibition of the Rho/ROCK pathway suppresses the proliferation and migration of airway smooth muscle cells, which may be associated with the downregulation of MYOCD.

The Function of RhoA/ROCK Pathway and MYOCD in Airway Remodeling in Asthma

INTRODUCTION

Asthma is a common chronic respiratory disease characterized by chronic airway inflammation and abnormal airway remodeling. The RhoA/ROCK pathway and myocardin-related transcription factor A (MRTF-A) demonstrate significant associations with the proliferation of airway smooth muscle cells (ASCMs), which tightly correlates with the process of airway remodeling. MYOCD, which is homologous to MRTF-A but specifically expressed in smooth muscle cells, potentially regulates RhoA/ROCK activated cell proliferation and subsequent airway remodeling.

METHODS

The RhoA/ROCK overexpression and silencing cell lines were constructed in vitro, as well as MYOCD overexpression/silencing. The cytoskeleton alterations induced by RhoA/ROCK pathway were identified by the measuring of globular actin and filamentous actin.

RESULTS

The comparison between controls for overexpression/silencing and ROCK overexpression/silencing revealed that MYOCD presented consistent change trends with cytoskeleton and RhoA/ROCK pathway. The ROCK1 facilitates the proliferation and migration of ASCMs. The MYOCD enhanced the proliferation and migration of HASMCs.

CONCLUSION

Our study indicates that Rho/ROCK/MYOCD is a key pathway involved in the migration and proliferation of airway smooth muscle cells. Inhibition of Rho/ROCK may be an effective approach to breaking the vicious cycle of asthmatic ASCMs proliferation, providing a novel strategy in treating asthma airway remodeling.

C-Phycocyanin Prevents Oxidative Stress, Inflammation, and Lung Remodeling in an Ovalbumin-Induced Rat Asthma Model

Asthma is a chronic immunological disease related to oxidative stress and chronic inflammation; both processes promote airway remodeling with collagen deposition and matrix thickening, causing pulmonary damage and lost function. This study investigates the immunomodulation of C-phycocyanin (CPC), a natural blue pigment purified from cyanobacteria, as a potential alternative treatment to prevent the remodeling process against asthma. We conducted experiments using ovalbumin (OVA) to induce asthma in Sprague Dawley rats. Animals were divided into five groups: (1) sham + vehicle, (2) sham + CPC, (3) asthma + vehicle, (4) asthma + CPC, and (5) asthma + methylprednisolone (MP). Our findings reveal that asthma promotes hypoxemia, leukocytosis, and pulmonary myeloperoxidase (MPO) activity by increasing lipid peroxidation, reactive oxygen and nitrogen species, inflammation associated with Th2 response, and airway remodeling in the lungs. CPC and MP treatment partially prevented these physiological processes with similar action on the biomarkers evaluated. In conclusion, CPC treatment enhanced the antioxidant defense system, thereby preventing oxidative stress and reducing airway inflammation by regulating pro-inflammatory and anti-inflammatory cytokines, consequently avoiding asthma-induced airway remodeling.

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.

Perimenstrual Asthma and Premenstrual Disorders in Adolescents with Asthma

BACKGROUND

Asthma is a common chronic disease in pediatric patients, and perimenstrual asthma (PMA), refers to the worsening of asthma symptoms during the perimenstrual period, mainly reported in adult women. However, there is limited information regarding the exacerbation of symptoms in the presence of premenstrual disorders (PMDs) in adolescents. The aim of this pilot observational study was to investigate the frequency and potential association of PMA and PMDs in a clinical sample of adolescents with asthma.

PATIENTS AND METHODS

The study included 50 adolescents (aged 12-18 years, mean 16.08 ± 2.35) with asthma and at least 2 years of gynecological age. The participants completed the Asthma Control Test (ACT) to assess asthma control (considered pathological if ACT score < 20) and the modified Premenstrual Symptoms Screening Tool for Adolescents (PSST-A) to evaluate PMDs.

RESULTS

A total of 75.5% of adolescents reported PMA. The prevalence of premenstrual symptoms did not significantly differ between the PMA and no-PMA group. Among the study sample, 38.7% experienced symptoms indicative of moderate/severe premenstrual syndrome, and 8.1% exhibited symptoms of premenstrual dysphoric disorder. Compared with the no-PMA group, patients with PMA showed a significant impairment in daily and home activities (P = .03 and P = .02, respectively) and exhibited a difference in the frequency of asthma symptoms (P < .001) and medication use (P ≤ .01).

CONCLUSION

Perimenstrual worsening of asthma symptoms may be common in adolescents with a severe form of asthma. Prospective data collection through menstrual diaries is necessary to further explore the association between PMA and PMDs. Identifying early risk factors for PMA could facilitate the development of preventive strategies and early interventions for adolescents with asthma.

Equine Asthma Does Not Affect Circulating Myostatin Concentrations in Horses

(1) Background: The number of horses suffering from chronic respiratory diseases, resembling human asthma, is increasing but there is still a lack of reliable and accurate methods to detect these disorders. Numerous studies have found elevated plasma concentrations of one of the myokines, namely, myostatin (MSTN), in people suffering from severe asthma. MSTN normally inhibits myoblast proliferation and differentiation through autocrine or paracrine signals. Therefore, given the pathogenesis of asthma, we hypothesize that MSTN could be a useful biomarker of equine asthma. Thus, this study aimed to compare the concentration of MSTN in the blood plasma of fully healthy and asthmatic horses. (2) Methods: A total of 61 horses were clinically examined to confirm or exclude the occurrence of equine asthma, including bronchoalveolar lavage (BAL) fluid cytology performed on 49 horses. This study included three groups of horses, two of which were clinically healthy, and one of which was asthmatic. (3) Results: The mean circulatory MSTN concentration determined using the ELISA method in asthmatic horses was significantly higher than that in clinically healthy young Thoroughbred racehorses (p < 0.05), but it did not differ as compared to the group of healthy, adult leisure horses. (4) Conclusions: The obtained results did not unambiguously support our original hypothesis that MSTM may be a reliable marker for the early diagnosis of equine asthma. To the best of the authors' knowledge, this is the first study to analyze the plasma MSTN concentration in equine asthma patients, and therefore further studies are needed to confirm our novel findings.

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.

Mechanistic analysis of Th2-type inflammatory factors in asthma

Background

The main pathological features of asthma are widespread chronic inflammation of the airways and restricted ventilation due to airway remodeling, which involves changes in a range of regulatory pathways. While the role of T helper type 2 (Th2)-related inflammatory factors in this process is known, the detailed understanding of how genes affect protein functions during airway remodeling is still lacking. This study aims to fill this knowledge gap by integrating gene expression data and protein function analysis, providing new scientific insights for a deeper understanding of the mechanisms of airway remodeling and for further development of asthma treatment strategies.

Methods

In this study, the mechanism of Th2-related inflammatory factors in tracheal remodeling was studied through differentially expressed gene (DEG) screening, enrichment analysis, protein-protein interaction (PPI) network construction, machine learning, and the construction of a line graph model.

Results

Our study revealed that S100A14, KRT6A, S100A2, ABCA13, UBE2C, RASSF10, PSCA, PLAT, and TIMP1 may be the key genes for airway remodeling; epithelial-mesenchymal transition (EMT)-related genes GEM, TPM4, SLC6A8, and SNTB1 may be involved in airway remodeling due to asthma; IL6 may affect the occurrence of airway remodeling by binding to UBE2C protein or by regulating GEM genes, respectively; IL6 and IL9 may affect the occurrence of airway remodeling by regulating the downstream Toll-like receptor (TLR) signaling pathway and thus IL6 and IL9 may influence the occurrence of tracheal remodeling by regulating downstream TLR signaling pathways.

Conclusions

This study further mined the asthma gene microarray database through bioinformatics analysis and identified key genes and important pathways affecting airway remodeling in asthma patients, providing new ideas to uncover the mechanism of airway remodeling due to asthma and then seek new therapeutic targets.

Nootkatone attenuates airway inflammation in asthmatic mice through repressing ROS-induced NLRP3 inflammasome activation

Nootkatone (NKT) exhibits potential pharmacological activities including anti-oxidation and anti-inflammation. Nevertheless, little is known about the roles of NKT in asthmatic airway inflammation. In the study, mice were sensitized and challenged with ovalbumin (OVA) to establish experimental allergic asthma model. After treatment with NKT, lung tissues, peripheral blood, and bronchoalveolar lavage fluid (BALF) were collected to assess inflammatory cytokines, oxidative stress, and pathological alternations. The effects of NKT on regulating reactive oxygen species (ROS)-induced NLR family pyrin domain containing 3 (NLRP3) inflammasome activation was assessed in IL-13-treated BEAS-2B cell model. We found that NKT treatment decreased the production of Th2 inflammatory cytokines (IL-4, IL-5, and IL-13) in BALF and IgE levels in serum, and alleviated inflammatory cell penetration, goblet cell proliferation, collagen accumulation, and mucus hypersecretion in lung tissues. NKT treatment mitigated oxidative stress and NLRP3 inflammasome activation in asthmatic mice. IL-13 treatment induced oxidative stress and NLRP3-mediated pyroptosis in BEAS-2B bronchial epithelial cells, whereas these effects were blocked by NKT. NKT protected against airway remodeling, as indicated by decreased epithelial-mesenchymal transition. Taken together, these results demonstrate that NKT mitigates asthmatic airway inflammation by inhibiting ROS-triggered NLRP3 activation and may be a potential agent for treating asthma.

Serum biomarkers of remodeling in severe asthma with fixed airway obstruction and the potential role of KL-6

Over 3% of asthmatic patients are affected by a particularly severe form of the disease ("severe asthma", SA) which is often refractory to standard treatment. Airway remodeling (AR), which can be considered a critical characteristic of approximately half of all patients with SA and currently thought to be the main mechanism triggering fixed airway obstruction (FAO), seems to be a key factor affecting a patient's outcome. Despite the collective efforts of internationally renowned experts, to date only a few biomarkers indicative of AR and no recognizable biomarkers of lung parenchymal remodeling have been identified. This work examines the pathogenesis of airway and lung parenchymal remodeling and the serum biomarkers that may be able to identify the severe asthmatic patients who may develop FAO. The study also aims to examine if Krebs von den Lungen-6 (KL-6) could be considered a diagnostic biomarker of lung structural damage in SA.

Fungal Aeroallergens-The Impact of Climate Change

The incidence of allergic diseases worldwide is rapidly increasing, making allergies a modern pandemic. This article intends to review published reports addressing the role of fungi as causative agents in the development of various overreactivity-related diseases, mainly affecting the respiratory tract. After presenting the basic information on the mechanisms of allergic reactions, we describe the impact of fungal allergens on the development of the allergic diseases. Human activity and climate change have an impact on the spread of fungi and their plant hosts. Particular attention should be paid to microfungi, i.e., plant parasites that may be an underestimated source of new allergens.

Mesenchymal Stem/Stromal Cells in Asthma Therapy: Mechanisms and Strategies for Enhancement

Asthma is a complex and heterogeneous disease characterized by chronic airway inflammation, airway hyperresponsiveness, and airway remodeling. Most asthmatic patients are well-established using standard treatment strategies and advanced biologicals. However, a small group of patients who do not respond to biological treatments or are not effectively controlled by available treatment strategies remain a clinical challenge. Therefore, new therapies are urgently needed for poorly controlled asthma. Mesenchymal stem/stromal cells (MSCs) have shown therapeutic potential in relieving airway inflammation and repairing impaired immune balance in preclinical trials owing to their immunomodulatory abilities. Noteworthy, MSCs exerted a therapeutic effect on steroid-resistant asthma with rare side effects in asthmatic models. Nevertheless, adverse factors such as limited obtained number, nutrient and oxygen deprivation in vitro, and cell senescence or apoptosis affected the survival rate and homing efficiency of MSCs, thus limiting the efficacy of MSCs in asthma. In this review, we elaborate on the roles and underlying mechanisms of MSCs in the treatment of asthma from the perspective of their source, immunogenicity, homing, differentiation, and immunomodulatory capacity and summarize strategies to improve their therapeutic effect.