Pathogenesis Of Asthma Research Articles

Gasdermin D silencing alleviates airway inflammation and remodeling in an ovalbumin-induced asthmatic mouse model

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. Gasdermin D (GSDMD) is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. Immunofluorescence staining was conducted on airway epithelial tissues obtained from both asthma patients and healthy controls (HCs) to evaluate the expression level of N-GSDMD. ELISA was used to measure concentrations of cytokines (IL-1β, IL-18, IL-17A, and IL-10) in serum samples collected from asthma patients and healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1β were significantly increased in samples with mild asthma compared with those from the controls. Then, wild type and Gsdmd-knockout (Gsdmd−/−) mice were used to establish asthma model. We performed histopathological staining, ELISA, and flow cytometry to explore the function of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the expression of N-GSDMD, IL-18, and IL-1β was enhanced in OVA-induced asthma mouse model. Gsdmd knockout resulted in attenuated IL-18, and IL-1β production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd−/− mice exhibit a significant reduction in airway inflammation and remodeling, which might be associated with reduced Th17 inflammatory response and M2 polarization of macrophages. Further, we found that GSDMD knockout may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion, migration, and macrophage M2 polarization by targeting Notch signaling pathway. These findings demonstrate that GSDMD deficiency profoundly alleviates allergic inflammation and tissue remodeling. Therefore, GSDMD may serve as a potential therapeutic target against asthma.

Selonsertib, an ASK1 Inhibitor, Ameliorates Ovalbumin-Induced Allergic Asthma during Challenge and Sensitization Periods.

Apoptosis signal-regulating kinase 1 (ASK1) is an upstream signaling molecule in oxidative stress-induced responses. Because oxidative stress is involved in asthma pathogenesis, ASK1 gene deficiency was investigated in animal models of allergic asthma. However, there is no study to investigate whether ASK1 inhibitors could be applied for asthma to date. Selonsertib, a potent and selective ASK1 inhibitor, was applied to BALB/c mice of an ovalbumin (OVA)-induced allergic asthma model. Selonsertib suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of selonsertib both before OVA sensitization and OVA challenge significantly reduced airway hyperresponsiveness, and suppressed eosinophil numbers and inflammatory cytokine levels in the bronchoalveolar lavage fluid. Histopathologic examination elucidated less inflammatory responses and reduced mucin-producing cells around the peribronchial regions of the lungs. Selonsertib also suppressed the IgE levels in serum and the protein levels of IL-13 in the bronchoalveolar lavage fluid. These results suggest that selonsertib may ameliorate allergic asthma by suppressing immune responses and be applicable to allergic asthma.

Exosomes in asthma: Underappreciated contributors to the pathogenesis and novel therapeutic tools.

Asthma, a chronic inflammatory disease with diverse pathomechanisms, presents challenges in developing personalized diagnostic and therapeutic approaches. This review aims to provide a comprehensive overview of the role of exosomes, small extracellular vesicles, in asthma pathophysiology and explores their potential as diagnostic biomarkers and therapeutic tools. A literature search was conducted to identify recent studies investigating the involvement of exosomes in asthma. The retrieved articles were analyzed to extract relevant information on the role of exosomes in maintaining lung microenvironment homeostasis, regulating inflammatory responses, and their diagnostic and therapeutic potential for asthma. Exosomes secreted by various cell types, have emerged as crucial mediators of intercellular communication in healthy and diseased conditions. Evidence suggest that exosomes play a significant role in maintaining lung microenvironment homeostasis and contribute to asthma pathogenesis by regulating inflammatory responses. Differential exosomal content between healthy individuals and asthmatics holds promise for the development of novel asthma biomarkers. Furthermore, exosomes secreted by immune and nonimmune cells, as well as those detected in biofluids, demonstrate potential in promoting or regulating immune responses, making them attractive candidates for designing new treatment strategies for inflammatory conditions such as asthma. Exosomes, with their ability to modulate immune responses and deliver therapeutic cargo, offer potential as targeted therapeutic tools in asthma management. Further research and clinical trials are required to fully understand the mechanisms underlying exosome-mediated effects and translate these findings into effective diagnostic and therapeutic strategies for asthma patients.

Chinese expert consensus on the diagnosis and management of severe asthma (2024 edition)

Severe asthma is the main cause of disability and death in patients with asthma, with a high risk of future disease, but also caused serious social and economic burden. The pathophysiological mechanisms such as obvious heterogeneity of airway inflammation, severe airway remodeling, influence of genetic factors, decreased glucocorticoid responsiveness, and many factors affecting asthma control make the treatment of severe asthma particularly difficult. In recent years, with the deepening of the understanding of the pathogenesis of asthma, especially the development of biologics targeting type 2 inflammation, a new approach has been opened up for the treatment of patients with severe asthma. How to correctly diagnose and evaluate severe asthma patients and how to choose treatment are still the perplexity and challenge in clinical practice. This expert consensus is based on the "Chinese Expert Consensus on the Diagnosis and Management of Severe Asthma" published in 2017 and combined with the latest research progress at home and abroad, and is updated on the definition, pathogenesis, diagnosis and evaluation, and treatment of severe asthma, especially the treatment recommendation for type 2 inflammatory biologics, so as to provide reference for the individualized diagnosis and treatment of severe asthma.

The investigation of the role of oral-originated Prevotella-induced inflammation in childhood asthma.

The oral and gut microbiota play significant roles in childhood asthma pathogenesis. However, the communication dynamics and pathogenic mechanisms by which oral microbiota influence gut microbiota and disease development remain incompletely understood. This study investigated potential mechanisms by which oral-originated gut microbiota, specifically Prevotella genus, may contribute to childhood asthma etiology. Oral swab and fecal samples from 30 asthmatic children and 30 healthy controls were collected. Microbiome composition was characterized using 16S rRNA gene sequencing and metagenomics. Genetic distances identified potential oral-originated bacteria in asthmatic children. Functional validation assessed pro-inflammatory properties of in silico predicted microbial mimicry peptides from enriched asthma-associated species. Fecal metabolome profiling combined with metagenomic correlations explored links between gut microbiota and metabolism. HBE cells treated with Prevotella bivia culture supernatant were analyzed for lipid pathway impacts using UPLC-MS/MS. Children with asthma exhibited distinct oral and gut microbiota structures. Prevotella bivia, P. disiens, P. oris and Bacteroides fragilis were enriched orally and intestinally in asthmatics, while Streptococcus thermophilus decreased. P. bivia, P. disiens and P. oris in asthmatic gut likely originated orally. Microbial peptides induced inflammatory cytokines from immune cells. Aberrant lipid pathways characterized asthmatic children. P. bivia increased pro-inflammatory and decreased anti-inflammatory lipid metabolites in HBE cells. This study provides evidence of Prevotella transfer from oral to gut microbiota in childhood asthma. Prevotella's microbial mimicry peptides and effects on lipid metabolism contribute to disease pathogenesis by eliciting immune responses. Findings offer mechanistic insights into oral-gut connections in childhood asthma etiology.

MicroRNA-mediated Krüppel-like factor 4 upregulation induces alternatively activated macrophage-associated marker and chemokine transcription in 4,4’-methylene diphenyl diisocyanate exposed macrophages

1. Occupational exposure to 4,4’-methylene diphenyl diisocyanate (MDI) is associated with occupational asthma (OA) development. Alveolar macrophage-induced recruitment of immune cells to the lung microenvironment plays an important role during asthma pathogenesis. Previous studies identified that MDI/MDI-glutathione (GSH)-exposure downregulates endogenous hsa-miR-206-3p/hsa-miR-381-3p. Our prior report shows that alternatively activated (M2) macrophage-associated markers/chemokines are induced by MDI/MDI-GSH-mediated Krüppel-Like Factor 4 (KLF4) upregulation in macrophages and stimulates immune cell chemotaxis. However, the underlying molecular mechanism(s) by which MDI/MDI-GSH upregulates KLF4 remain unclear. 2. Following MDI-GSH exposure, microRNA(miR)-inhibitors/mimics or plasmid transfection, endogenous hsa-miR-206-3p/hsa-miR-381-3p, KLF4, or M2 macrophage-associated markers (CD206, TGM2), and chemokines (CCL17, CCL22, CCL24) were measured by either RT-qPCR, western blot, or luciferase assay. 3. MDI-GSH exposure downregulates hsa-miR-206-3p/hsa-miR-381-3p by 1.46- to 9.75-fold whereas upregulates KLF4 by 1.68- to 1.99-fold, respectively. In silico analysis predicts binding between hsa-miR-206-3p/hsa-miR-381-3p and KLF4. Gain- and loss-of-function, luciferase reporter assays and RNA-induced silencing complex-immunoprecipitation (RISC-IP) studies confirm the posttranscriptional regulatory roles of hsa-miR-206-3p/hsa-miR-381-3p and KLF4 in macrophages. Furthermore, hsa-miR-206-3p/hsa-miR-381-3p regulate the expression of M2 macrophage-associated markers and chemokines via KLF4. 4. In conclusion, hsa-miR-206-3p/hsa-miR-381-3p play a major role in regulation of MDI/MDI-GSH-induced M2 macrophage-associated markers and chemokines by targeting the KLF4 transcript, and KLF4-mediated regulation in macrophages.

Asthma: a New Approach to the Bronchial Epithelium

The bronchial epithelium serves as a critical defense line against environmental insults, acting not merely as a barrier but as a complex, dynamic system enriched with diverse cell types such as ciliated cells, goblet cells, and basal cells. Recent advancements in single-cell ribonucleic acid (RNA) sequencing have further unveiled the complexity of this layer by identifying additional cell types like ionocytes, neuroendocrine cells, tuft cells, deuterosomal cells, club cells and mucus ciliated cells. These cells collectively maintain respiratory health through various mechanisms including the mucociliary escalator, mucus production, airway repair, and immune modulation. Disruptions in the epithelial barrier can lead to respiratory diseases like asthma, highlighting the importance of understanding these intricate cellular relationships for developing targeted therapies. This epithelial complexity is crucial for pulmonary homeostasis and the pathogenesis of asthma, where abnormal epithelial remodeling and dysfunction are central. The identification of a novel mucous ciliated cell state in asthma, co-expressing genes associated with both ciliated and goblet cells, offers new insights into the disease’s pathogenesis and therapeutic targets. The epithelial barrier’s integrity, maintained by tight junctions and adherents’ junctions, is essential for protecting the underlying tissue from environmental threats. However, in asthma, this barrier is compromised, leading to increased allergen permeability, airway hyperresponsiveness, inflammation, and remodeling. Despite advances, the need for novel concepts in asthma pathogenesis remains, particularly to address the limitations of the current T helper 2-dominant paradigm in explaining the connection between airway inflammation and remodeling. Understanding the molecular mechanisms underlying epithelial barrier dysfunction could pave the way for novel asthma treatments focused on enhancing barrier integrity, ultimately improving patient outcomes.

TOLL-LIKE RECEPTORS AND BRONCHIAL ASTHMA: PART 1

Bronchial asthma is a chronic disease of the respiratory tract, which is formed by the action of endogenous factors and environmental influences. At the same time, T-helpers of the second type play a major role in the development of bronchial asthma, causing hyperreactivity and inflammation of the respiratory tract. However, the data that bronchial asthma in most cases is an allergic, eosinophilic, T-helper-mediated disease of the second type is insufficient to establish complete control over the course of disease. This is probably due to the fact that endogenous factors play an important role in the pathogenesis of asthma, knowledge of which is currently limited. Toll-like receptors are an established element of the development of bronchial asthma. Their insufficient function or, conversely, the launch of an excessive immune response is associated with the initiation of the disease or its exacerbations. Expanding the understanding of Toll-like receptors leads not only to a more detailed understanding of the pathogenesis of bronchial asthma, but also to the application of this knowledge in practice.

Interrelation between gut microbiota and bronchial asthma

Bronchial asthma is a chronic disease of the respiratory tract, and its etiology and pathogenesis have not been studied adequately. Many authors suggest that intestinal microbiota significantly contributed to its etiology. The existence of a gut–lung connection, through which bacterial metabolites influence airway sensibilization, has been proven. Certainly, the formation of this connection in childhood is important. This study provides a review of indigenous and foreign studies concerning the influence of the quantitative and qualitative compositions of intestinal microbiota and certain metabolites of commensals on the manifestation of bronchial asthma. This topic is relevant because of the widespread overuse of antibiotic therapy and the availability of possible ways to prevent the development of bronchial asthma if the influence of the microbiota on its pathogenesis is detected. This study also tried to examine the influence of antibiotic therapy on pregnant women and young children at risk of bronchial asthma, a relationship confirmed in many studies. Despite the large number of studies, the use of probiotics for the treatment and prevention of this disease is still debatable.

Biological treatment options for severe asthma in Poland

Intruduction and purpose: Patients with severe asthma account for approximately 3% to 10% of all asthma patients. They have higher hospital utilization rates and treatment costs than patients with non-severe asthma. Previously, treatment options for these patients were limited due to unacceptable side effects. However, the advent of biologic therapies has provided promising targeted therapy for these patients. State of knowledge: Biologic therapies target inflammatory modulators that play a key role in the pathogenesis of asthma, particularly in patients with high T2 cells. These therapies have shown promising results in reducing asthma symptoms, improving lung function, decreasing the use of oral corticosteroids, and enhancing patients' quality of life. Conclusions: This article reviews the mechanism of action, efficacy, and indications of currently approved biologic drugs available in Poland, as well as potential therapeutic targets for the future.

Selective production of IL-33-neutralizing autoantibody ameliorates asthma responses and severity

BackgroundNatural anti-cytokine autoantibodies can regulate homeostasis of infectious and inflammatory diseases. The anti-cytokine autoantibody profile and relevance to the pathogenesis of asthma are unknown. We aim to identify key anti-cytokine autoantibodies in asthma patients, and reveal their immunological function and clinical significance. MethodsA Luciferase Immunoprecipitation System was used to screen serum autoantibodies against 11 key cytokines in patients with allergic asthma and healthy donors. The antigen-specificity, immunomodulatory functions and clinical significance of anti-cytokine autoantibodies were determined by ELISA, qPCR, neutralization assays and statistical analysis, respectively. Potential conditions for autoantibody induction were revealed by in vitro immunization. ResultsOf 11 cytokines tested, only anti-IL-33 autoantibody was significantly increased in asthma, compare to healthy controls, and the proportion positive was higher in patients with mild-to-moderate than severe allergic asthma. In allergic asthma patients, the anti-IL-33 autoantibody level correlated negatively with serum concentration of pathogenic cytokines (e.g., IL-4, IL-13, IL-25 and IL-33), IgE, and blood eosinophil count, but positively with mid-expiratory flow FEF25–75%. The autoantibodies were predominantly IgG isotype, polyclonal and could neutralize IL-33-induced pathogenic responses in vitro and in vivo. The induction of the anti-IL-33 autoantibody in blood B-cells in vitro required peptide IL-33 antigen along with a stimulation cocktail of TLR9 agonist and cytokines IL-2, IL-4 or IL-21. ConclusionsSerum natural anti-IL-33 autoantibodies are selectively induced in some asthma patients. They ameliorate key asthma inflammatory responses, and may improve lung function of allergic asthma.

Iron controls the development of airway hyperreactivity by regulating ILC2 metabolism and effector function.

Group 2 innate lymphoid cells (ILC2s) rapidly induce a type 2 inflammation in the lungs in response to allergens. Here, we focused on the role of iron, a critical nutritional trace element, on ILC2 function and asthma pathogenesis. We found that transferrin receptor 1 (TfR1) is rapidly up-regulated and functional during ILC2 activation in the lungs, and blocking transferrin uptake reduces ILC2 expansion and activation. Iron deprivation reprogrammed ILC2 metabolism, inducing a HIF-1α-driven up-regulation of glycolysis and inhibition of oxidative mitochondrial activity. Consequently, we observed that in vivo iron chelation or induction of hypoferremia reduced the development of airway hyperreactivity in experimental models of ILC2-driven allergic asthma. Human circulating ILC2s rapidly induced TfR1 during activation, whereas inhibition of iron uptake or iron deprivation reduced effector functions. Last, we found a negative relationship between circulating ILC2 TfR1 expression and airway function in cohorts of patients with asthma. Collectively, our studies define cellular iron as a critical regulator of ILC2 function.

Iron-related Genes and Proteins Involved in Iron Homeostasis in Animal Models of Allergic Asthma: A Systematic Review.

The involvement of the immune oxidative stress response in the pathophysiology and pathogenesis of allergic asthma is well documented. However, reports on the role of iron homeostasis in allergic asthma is scarce. Therefore, this study aims to identify iron-related genes and proteins in mouse models of allergic asthma. Related articles were identified from SCOPUS and Web of Science databases. The article search was limited to publications in English, within a 10-year period (2014 - 2023, up to 16 August 2023) and original/research papers. All identified articles were screened for eligibility using the inclusion and exclusion criteria. All eligible articles were quality appraised prior to data extraction. Five studies were selected for data extraction. Based on the extracted data, three themes and seven subthemes related to iron homeostasis were identified. The type of samples and analytical methods used were also identified. In conclusion, our study elucidates that iron-related proteins are regulated in animal models of allergic asthma. However, the currently available data do not allow us to conclude whether the disease model resulted in iron accumulation or depletion. Therefore, further studies with other related markers should be conducted.

Airway and Systemic Immunoglobulin Profiling and Immune Response in Adult Asthma

IntroductionImmunoglobulins play a vital role in host immune response and in the pathogenesis of conditions like asthma. Therapeutic agents such as monoclonal antibodies target specific elements of the asthmatic inflammatory cascade. Decisions to utilize these medications are often based on systemic inflammatory profiling without direct insight into the airway inflammatory profile. We sought to investigate the relationship between immunoglobulin and cytokine profiles in the airway and systemic immune compartments of adult asthmatics.MethodsBlood sampling and bronchoscopy with bronchoalveolar lavage (BAL) were performed in 76 well-defined adult asthmatics. Antibody and cytokine profiles were measured in both BAL and serum using ELISA and quantibody arrays.ResultsThere was no relationship between BAL and serum levels of IgE. This is of significance in an asthma population. For some analytes, correlation analysis was significant (P < 0.05) indicating representativeness of our cohort and experimental setup in those cases. Nevertheless, the predictive power (r2) of the BAL-to-serum comparisons was mostly low except for TNF-α (r2 = 0.73) when assuming a simple (linear) relationship.ConclusionThis study highlights the importance of sample site when investigating the roles of immunoglobulins and cytokines in disease pathogenesis and suggests that both localized and systemic immune responses are at play. The prescription of asthma monoclonal therapy is generally based on systemic evaluation of cytokine and immunoglobulin levels. Our research suggests that this approach may not fully reflect the pathophysiology of the disease and may provide insight into why some patients respond to these targeted therapies while others do not.

DUSP8 Promotes IL-9 Transcription by Inactivating Pur-α leading to asthma and atopic dermatitis

Abstract Dual-specificity phosphatase 8 (DUSP8) is a member of the DUSP family. DUSP8 dephosphorylates and inactivates the kinase JNK. DUSP8 protein levels are predominantly expressed in CD4+ T cells and platelets. DUSP8 dephosphorylates and inactivates specifically JNK in Jurkat T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T-cell-specific DUSP8 conditional knockout (T-DUSP8 cKO, DUSP8f/f;CD4-Cre) mice, mass spectrometry, and chromatin-immunoprecipitation sequencing, we found that DUSP8 stimulated IL-9 gene expression and Th9 differentiation. TGF-β stimulated DUSP8 phosphatase activity in T cells. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-β signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, Il-9 mRNA levels in murine T cells were induced in Pur-α knockout. Reduction of IL-9 levels in T cells of T-DUSP8 cKO mice was reversed by Pur-α heterozygous knockout. Consistently, T-DUSP8 cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in allergy, autoimmune responses, and anti-tumor immunity. Remarkably, DUSP8 overexpression and DUSP8-Pur-α interaction indeed occurred in the peripheral blood T cells of patients with asthma or atopic dermatitis, contributing to IL-9 overproduction in patients’ T cells. Thus, DUSP8 plays a critical role in the pathogenesis of asthma and atopic dermatitis, as well as autoimmune disease and cancer.

The barrier-protective effect of β-eudesmol against type 2-inflammatory cytokine-induced tight junction disassembly in airway epithelial cells.

Allergic inflammation, which is the pathogenesis of allergic rhinitis and asthma, is associated with disruption of the airway epithelial barrier due to the effects of type 2 inflammatory cytokines, i.e. interleukin-4 and interleukin-13 (IL-4/13). The anti-allergic inflammatory effect of β-eudesmol (BE) on the tight junction (TJ) of the airway epithelium has not previously been reported. Herein, the barrier protective effect of BE was determined by measurement of transepithelial electrical resistance and by paracellular permeability assay in an IL-4/13-treated 16HBE14o- monolayer. Pre-treatment of BE concentration- and time- dependently inhibited IL-4/13-induced TJ barrier disruption, with the most significant effect observed at 20 μM. Cytotoxicity analyses showed that BE, either alone or in combination with IL-4/13, had no effect on cell viability. Western blot and immunofluorescence analyses showed that BE inhibited IL-4/13-induced mislocalization of TJ components, including occludin and zonula occludens-1 (ZO-1), without affecting the expression of these two proteins. In addition, the mechanism of the TJ-protective effect of BE was mediated by inhibition of IL-4/13-induced STAT6 phosphorylation, in which BE might serve as an antagonist of cytokine receptors. In silico molecular docking analysis demonstrated that BE potentially interacted with the site I pocket of the type 2 IL-4 receptor, likely at Asn-126 and Tyr-127 amino acid residues. It can therefore be concluded that BE is able to prevent IL-4/13-induced TJ disassembly by interfering with cytokine-receptor interaction, leading to suppression of STAT6-induced mislocalization of occludin and ZO-1. BE is a promising candidate for a therapeutic intervention for inflammatory airway epithelial disorders driven by IL-4/13.

Gut-lung axis and asthma: A historical review on mechanism and future perspective.

Gut microbiota are closely related to the development and regulation of the host immune system by regulating the maturation of immune cells and the resistance to pathogens, which affects the host immunity. Early use of antibiotics disrupts the homeostasis of gut microbiota and increases the risk of asthma. Gut microbiota actively interact with the host immune system via the gut-lung axis, a bidirectional communication pathway between the gut and lung. The manipulation of gut microbiota through probiotics, helminth therapy, and fecal microbiota transplantation (FMT) to combat asthma has become a hot research topic. BODY: This review mainly describes the current immune pathogenesis of asthma, gut microbiota and the role of the gut-lung axis in asthma. Moreover, the potential of manipulating the gut microbiota and its metabolites as a treatment strategy for asthma has been discussed. The gut-lung axis has a bidirectional effect on asthma. Gut microecology imbalance contributes to asthma through bacterial structural components and metabolites. Asthma, in turn, can also cause intestinal damage through inflammation throughout the body. The manipulation of gut microbiota through probiotics, helminth therapy, and FMT can inform the treatment strategies for asthma by regulating the maturation of immune cells and the resistance to pathogens.

Role of Reactive Oxygen Species in the Pathogenesis of Bronchial Asthma and Obstructive Pulmonary Diseases: Systematic Review

The article discusses the role of reactive oxygen species (ROS) in the pathogenesis of bronchial asthma and obstructive pulmonary diseases. The review follows a structured approach beginning with a comprehensive search of electronic databases, then findings from the included studies were summarized and used to draw comprehensive conclusions. The authors state that increased activity of oxidative processes and insufficient activity of the antioxidant system lead to the accumulation of ROS in the respiratory tract. This leads to direct damage to epithelial cells, activation of inflammatory cells, and stimulation of inflammatory mediators. ROS also activate transcription factors that increase inflammation and airway obstruction. Thus, maintaining the balance of the oxidant-antioxidant system is an important strategy for the treatment of these diseases.Keywords: Reactive oxygen species; Bronchial asthma; Chronic obstructive pulmonary disease; Oxidative stress; Antioxidant system

Hispidulin Alleviates Mast Cell-Mediated Allergic Airway Inflammation through FcεR1 and Nrf2/HO-1 Signaling Pathway.

Allergic asthma is a type 2 immune-response-mediated chronic respiratory disease. Mast cell activation influences the pathogenesis and exacerbation of allergic asthma. Therefore, the development of mast cell-targeting pharmacotherapy is important for managing allergic airway inflammation. We investigated the efficacy of hispidulin (HPD), natural flavone, in a mast-cell-mediated ovalbumin (OVA)-induced allergic airway inflammation model. HPD alleviated symptoms of allergic asthma and decreased the levels of immunoglobulin (Ig) E, type 2 inflammation, immune cell infiltration, and mast cell activation in the lung. Furthermore, in vivo analysis confirmed the efficacy of HPD through the evaluation of IgE-mediated allergic responses in a mast cell line. HPD treatment inhibited mast cell degranulation through inhibition of the FcεR1 signaling pathway and suppressed the expression of inflammatory cytokines (TNF-α, IL-4, IL-6, and IL-13) through suppression of the NF-κB signaling pathway. The antioxidant effects of HPD in activated mast cells were identified through modulation of antioxidant enzymes and the Nrf2/HO-1 signaling pathway. In conclusion, HPD may be a potential therapeutic candidate for allergic airway inflammation of asthma and acts by suppressing mast cell activation and oxidative stress.

Cellular senescence-Related genes define the immune microenvironment and molecular characteristics in severe asthma patients

Recent studies have shown that cellular senescence is involved in the pathogenesis of severe asthma (SA). The objective of this study was to investigate the role of cellular senescence-related genes (CSGs) in the pathogenesis of SA. Here, 54 differentially expressed CSGs were identified in SA patients compared to healthy control individuals. Among the 54 differentially expressed CSGs, 3 CSGs (ETS2, ETS1 and AURKA) were screened using the LASSO regression analysis and logistic regression analysis to establish the CSG-based prediction model to predict severe asthma. Moreover, we found that the protein expression levels of ETS2, ETS1 and AURKA were increased in the severe asthma mouse model. Then, two distinct senescence subtypes of SA with distinct immune microenvironments and molecular biological characteristics were identified. Cluster 1 was characterized by increased infiltration of immature dendritic cells, regulatory T cells, and other cells. Cluster 2 was characterized by increased infiltration levels of eosinophils, neutrophils, and other cells. The molecular biological characteristics of Cluster 1 included aerobic respiration and oxidative phosphorylation, whereas the molecular biological characteristics of Cluster 2 included activation of the immune response and immune receptor activity. Then, we established an Random Forest model to predict the senescence subtypes of SA to guide treatment. Finally, potential drugs were searched for each senescence subgroup of SA patients via the Connectivity Map database. A peroxisome proliferator-activated receptor agonist may be a potential therapeutic drug for patients in Cluster 1, whereas a tachykinin antagonist may be a potential therapeutic drug for patients in Cluster 2. In summary, CSGs are likely involved in the pathogenesis of SA, which may lead to new therapeutic options for SA patients.