IgE and eosinophils as therapeutic targets in asthma

Increased Hippocampal Glucocorticoid Receptor Expression and Reduced Anxiety-Like Behavior Following Tuina in a Rat Model With Allergic Airway Inflammation

OBJECTIVE

This study aimed to explore the influence mechanism of Tuina on anxiety-like behavior in immature rats with allergic airway inflammation (AAI).

METHODS

A total of 27 Sprague-Dawley male rats (aged ∼5 weeks) were divided randomly into control, AAI, and AAI with Tuina groups (9 rats per group). The anxiety-like behavior was assessed by an open field test and elevated plus-maze test. Allergic airway inflammation was assessed based on the pathological score of the lung, plasma ovalbumin-specific immunoglobulin E, interleukin 4, interleukin 5, and tumor necrosis factor-alpha levels. Glucocorticoid receptor (GR) messenger RNA and protein expression in the hippocampus and lung were detected by polymerase chain reaction and immunohistochemistry, respectively. Meanwhile, corticotropin-releasing hormone (CRH) messenger RNA in the hypothalamus, the plasma levels of adrenocorticotropic hormone and corticosterone were also determined respectively by polymerase chain reaction and enzyme-linked immunosorbent assay for hypothalamic-pituitary-adrenal axis (HPA) function.

RESULTS

The AAI group had obvious anxiety-like behavior and hyperactive HPA axis, along with decreased GR expression in the hippocampus and lung. Following Tuina, AAI and the anxiety-like behavior were efficiently reduced, and the hyperactivity of HPA axis was efficiently inhibited, along with enhanced GR expression in the hippocampus and lung.

CONCLUSION

Glucocorticoid receptor expression in the hippocampus and lung was enhanced, and anxiety-like behavior was reduced following Tuina in rats with AAI.

A typical presentation of moxifloxacin-induced DRESS syndrome with pulmonary involvement: a case report and review of the literature

Background

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a kind of hypersensitivity drug reaction involving the skin and multiple internal organ systems. Moxifloxacin has rarely been reported to be a drug that is associated with DRESS syndrome. Lungs are less frequently involved in DRESS syndrome, but their involvements may herald more serious clinical processes. We present a rare typical case of moxifloxacin-induced DRESS syndrome with lungs involved. Valuable clinical data such as changes in the pulmonary imaging and pulmonary function tests was recorded. This case is important for the differential diagnosis of DRESS syndrome with lungs involved by providing clinical manifestations, CT imaging, pulmonary function tests, and biopsy pathological characteristics. The changes in pulmonary imaging and pulmonary function tests may help us understand the mechanism of DRESS syndrome further.

Case presentation

We report a case of a 47-year-old woman who was treated with oral moxifloxacin for community-acquired pneumonia. The patient subsequently developed a cough, fever, liver injury, skin rash, hematologic abnormalities, and shortness of breath (SOB) followed by pharyngeal herpes and peripheral neuritis. These symptoms, clinical lab index, and CT scan of the lungs improved after the withdrawal of moxifloxacin. The probability of moxifloxacin-induced DRESS syndrome was rated as “Definite”, with 7 scores graded by RegiSCAR. A literature search was also performed with “fluoroquinolones,” “moxifloxacin,” “ciprofloxacin,” “levofloxacin,” “delafloxacin,” and “DRESS” or “drug-induced hypersensitivity syndrome (DIHS)” as the keywords that were put into PubMed. The overall pulmonary involvement was approximately 9.1% (1/11). It is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. We summarized detailed clinical data, including pulmonary imaging and pulmonary function changes.

Conclusion

This is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. Prompt recognition and correct diagnosis can promote appropriate treatment and accelerate recovery. This case is important for us as a reference in the differential diagnosis of DRESS syndrome and helps us further understand the mechanism of DRESS syndrome.

Documento de consenso de asma grave en adultos. Actualización 2022

Severe asthma is a heterogeneous syndrome with several clinical variants and often represents a complex disease requiring a specialized and multidisciplinary approach, as well as the use of multiple drugs. The prevalence of severe asthma varies from one country to another, and it is estimated that 50% of these patients present a poor control of their disease. For the best management of the patient, it is necessary a correct diagnosis, an adequate follow-up and undoubtedly to offer the best available treatment, including biologic treatments with monoclonal antibodies. With this objective, this consensus process was born, which began in its first version in 2018, whose goal is to offer the patient the best possible management of their disease in order to minimize their symptomatology. For this 2020 consensus update, a literature review was conducted by the authors. Subsequently, through a two-round interactive Delphi process, a broad panel of asthma experts from SEPAR and the regional pulmonology societies proposed the recommendations and conclusions contained in this document.

Ethanolic Extract of Tridax procumbens Mitigates Pulmonary Inflammation via Inhibition of NF-κB/p65/ERK Mediated Signalling in an Allergic Asthma Model

BACKGROUND

Tridax procumbens is a traditionally used medicinal plant with high content of active phytoconstituents having anti-inflammatory activity. Accumulating evidences have shown that Tridax procumbens efficaciously diminished oxidative stress and inflammation. However the anti-inflammatory role of Tridax procumbens is not obscured in allergic asthma.

PURPOSE

Aim of this study was to decipher the anti-inflammatory role of Tridax procumbens in allergic asthma and its underlying mechanism.

METHODS

Ethanolic extract of Tridax procumbens (TP) was prepared and major phytoconstituents (flavonoids) were characterized by biochemical and UPLC/MS analysis. Rats were sensitized and challenged with environmental allergen ovalbumin (OVA) and lipopolysaccharide (LPS) to establish an allergic asthma model. Persuasive anti-inflammatory role of TP was demonstrated in vivo (100, 200 and 400 mg/kg) and in vitro (250, 125, 75 and 25 µg/ml) experiments.

RESULTS

Characterization by UPLC/MS analysis showed the presence of various bioactive flavonoids. In in vitro study, significant reduction in ROS production, apoptosis and mitochondrial dysfunction were observed in alveolar type II cells upon pre-treatment with TP (250, 125, 75 and 25 µg/ml) in a concentration-dependant manner. In vivo, TP (200 mg/kg) oral administration showed robust anti-oxidative activity. TP treatment abrogated bronchial wall thickening, immune cell infiltration and bronchial wall fibre deposition. Immunohistochemical analysis showed the diminished expression of IL-1β, IL-6 in bronchial epithelium and vascular endothelium. TP abrogated inflammation by reducing the level of inflammatory cytokines including IL-2, IFN-γ, IL-6 and MCP-1, as well as inflammatory markers including TWEAK, TNF-α, TNF-R1 and its downstream transcription factor NF-ҡB/p65 activation and its nuclear translocation. Western blot analysis of TP treated lung tissue and alveolar type II cells showed reduced phosphorylation of ERK1/2 significantly.

CONCLUSION

TP exhibited anti-inflammatory activity by inhibition of ROS production and down-regulation of NF-ҡB/ERK signalling in vitro and in vivo asthma model. Thus, TP can be envisaged as an effective anti-inflammatory agent for OVA-induced allergic asthma.

Therapeutic Potential of Combining IL-6 and TNF Blockade in a Mouse Model of Allergic Asthma

Combined anti-cytokine therapy is a promising therapeutic approach for uncontrolled steroid-resistant asthma. In this regard, simultaneous blockade of IL-4 and IL-13 signaling by Dupilumab (anti-IL-4Ra monoclonal antibody) was recently approved for severe eosinophilic asthma. However, no therapeutic options for neutrophilic asthma are currently available. Recent advances in our understanding of asthma pathogenesis suggest that both IL-6 and TNF may represent potential targets for treatment of severe neutrophilic asthma. Nevertheless, the efficacy of simultaneous pharmacological inhibition of TNF and IL-6 in asthma was not yet studied. To evaluate the potency of combined cytokine inhibition, we simultaneously administrated IL-6 and TNF inhibitors to BALB/c mice with HDM-induced asthma. Combined IL-6/TNF inhibition, but not individual blockade of these two cytokines, led to complex anti-inflammatory effects including reduced Th2-induced eosinophilia and less prominent Th17/Th1-mediated neutrophilic infiltrate in the airways. Taken together, our results provide evidence for therapeutic potential of combined IL-6/TNF inhibition in severe steroid-resistant asthma.

Dupilumab: An emerging therapy in allergic fungal rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is a highly resistant disease and is challenging to treat. Patients with recurrent attacks of the disease despite surgical management can benefit from biologics as adjunct therapies. Dupilumab has shown promising endpoints in patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). This case series reports 4 patients with resistant AFRS concomitant with asthma, for which dupilumab therapy was administered. Long-term follow-ups showed that dupilumab improved the symptoms and improved the results of objective tools such as imaging and pulmonary function test.

Oral administration of Lactobacillus plantarum CQPC11 attenuated the airway inflammation in an ovalbumin (OVA)-induced Balb/c mouse model of asthma

This study investigated the antiasthmatic and anti-inflammatory effects of Lactobacillus plantarum-CQPC11 (LP-CQPC11) on ovalbumin (OVA)-induced asthmatic Balb/c mice. Administration of different doses of LP-CQPC11 (10⁵ , 10⁷ , and 10⁹ colony-forming unit [CFU]/mouse) effectively reduced airway hyperresponsiveness (AHR) and the lung W/D ratio in asthmatic mice. LP-CQPC11 treatment reduced the accumulation of inflammatory cells in the BALF and attenuated histologic edema in asthmatic mice. Administration of LP-CQPC11 decreased the serum levels of OVA-specific IgE, IgE, and OVA-specific IgG1. LP-CQPC11 treatment decreased the levels of inflammatory cytokines (TNF-α, IL-4, IL-13, IL-5, and IL-6) in the BALF of asthmatic mice. In addition, LP-CQPC11 also elevated the mRNA levels of Foxp3 and T-bet and decreased the mRNA levels of Gata3 and RORγt in asthmatic mice lungs. Administration of LP-CQPC11 also reduced OVA-induced oxidative stress by improving the activities of GSH-Px, SOD, and catalase in the lungs. Finally, LP-CQPC11 treatment also significantly decreased the activation of the NF-κB pathway to modulate the inflammatory reaction in the lungs of asthmatic mice. The results from this study clearly demonstrated that oral administration of LP-CQPC11 exhibited outstanding activity in attenuating OVA-induced asthma in a mouse model. Furthermore, LP-CQPC11 may be an effective microecologic agent in preventing allergic asthma in the future. PRACTICAL APPLICATIONS: Allergic asthma is a common chronic inflammation-associated respiratory disease. Lactic acid bacteria (LAB) are known as a health product involved in modulating immune tolerance and play important roles in disease prevention and treatment. Many studies have reported that LAB, as probiotics, exhibits great antioxidation, anticancer, and anti-inflammatory activities and have health benefits in gastrointestinal disorders. In fact, human studies have confirmed that Lactobacillus rhamnosus strains have an effective activity to reduce the risk of allergic asthma. LP-CQPC11 was isolated from Sichuan pickled cabbages (a type of LAB-fermented vegetable product, also called Sichuan paocai) and was reported to reduce d-galactose-induced aging in mice in our previous study. However, the antiasthmatic and anti-inflammatory activities of LP-CQPC11 are unclear. The current study investigated the antiasthmatic and anti-inflammatory effects of LP-CQPC11 on OVA-induced asthmatic Balb/c mice.

Pediatric usage of Omalizumab: A promising one

Allergic and related diseases have a substantial epidemiological impact on the pediatric population. Small molecule-based medicines have been traditionally used to manage the diseases. Omalizumab is the first monoclonal antibody-based medicine used in children's allergy and shows great promises. It binds to free IgE and prevents it from binding to IgE receptors, thus interrupting the IgE-dependent allergic inflammatory cascade. Vast amounts of data demonstrate its effectiveness and well tolerance by patients, including the children. However, the drug was only approved to use in allergic asthma and chronic spontaneous urticaria (CSU), though other applications were explored in clinical trials. In this review, we summarized current pediatric applications of omalizumab in allergic diseases, focusing on its usages beyond asthma and CSU, including allergic rhinitis, allergic bronchopulmonary aspergillosis, vernal keratoconjunctivitis, food allergy and atopic dermatitis. In addition, we highlighted the unmet needs and controversial issues of anti-IgE therapy.

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Omalizumab, the first monoclonal antibody-based medicine used in children's allergy, shows great promise.

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Omalizumab is effective in relieving symptoms associated with almost every children's allergic and related diseases beyond asthma and CSU.

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There are unmet needs and controversial issues of anti-IgE therapy in allergic and related diseases.

The Therapeutic Effect of Traditional LiuJunZi Decoction on Ovalbumin-Induced Asthma in Balb/C Mice

Aim

To investigate the therapeutic effect of LiuJunZi decoction (LJZD) in an experimental model of asthma and uncover its potential mechanism.

Materials and Methods

The ovalbumin (OVA) was applied to induce asthma in Balb/C mice, and LJZD was orally administrated to asthmatic mice. The lung function and histological lesion were evaluated by airway hyperresponsiveness assay, lung edema assay, and hematoxylin and eosin staining. The amounts of CD4⁺CD25⁺Foxp3⁺ T_Reg cells were analyzed through combining fluorescent antibody staining with flow cytometry assay. The levels of inflammatory factors and immunoglobulins were detected by enzyme-linked immuno sorbent assay (ELISA). The expression of miR-21 and miR-146a was investigated by real-time PCR. The protein expression of activating protein-1 (AP-1), nuclear factor kappa-B (NF-κB), and NF-κB inhibitor alpha (IκBα) was determined by western blotting.

Results

LJZD improves OVA-induced asthma in Balb/C mice, which is manifested by decreasing lung edema, Penh levels, lung histological lesion, and inflammatory cell infiltration. LJZD increased the number of CD4⁺CD25⁺Foxp3⁺ T_Reg cells in blood mononuclear cells from asthmatic mice. Furthermore, LJZD reduced the levels of tumor necrosis factor-α (TNF-α), interleukin- (IL-) 4, IL-6, IgG1, and IgE, but increased interferon gamma (IFN-γ) expression, in serum of asthmatic mice, and also decreased the expression of IL-17a, IL-23, IL-25, and thymic stromal lymphopoietin (Tslp) in lung tissues. In addition, miR-21 and miR-146a expression and phospho (p)-NF-κB, p-IκBα, and AP-1 protein expression were inhibited by LJZD in lung tissues from asthmatic mice.

Conclusion

LJZD improved OVA-induced asthma in Balb/C mice by inhibiting allergic inflammation and Th2 immunoreaction, which might be associated with the inactivation of the NF-κB signaling pathway.

Reduction/elimination of blood eosinophils in severe asthma: should there be a safety consideration?

INTRODUCTION

Eosinophils play a central role in the inflammation of asthma and are the target of new biologic treatments for patients with severe asthma. Biologics targeting the IL-5 pathway have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life, accompanied by reduced or even eliminated blood eosinophils. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of these long-term therapies that reduce or eliminate them.

AREAS COVERED

In this review, we explore the current safety profile of biologics regarding the impact they may have on blood eosinophils, trying to answer the question about any safety consideration.

EXPERT OPINION

Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that reduce or eliminate these blood cells.

Ginsenoside Rh1 attenuates ovalbumin-induced asthma by regulating Th1/Th2 cytokines balance

Ginsenoside Rh1 (Rh1) has anti-inflammatory effects in asthma mice, but the underlying mechanism remains unclear. BALB/c mice were sensitized and challenged with ovalbumin (OVA) to construct asthma model. Mice received Rh1 or tiotropium bromide 0.5 h before OVA challenge. Airway morphology and airway remodeling were assessed by HE staining and Masson's trichrome staining, respectively. Th1/Th2 cytokines in serum or broncho alveolar lavage fluid (BALF) were measured by ELISA kits. Rh1 significantly alleviated the lung resistance and airway resistance, and reduced the number of total inflammation cells, eosinophils, neutrophils, and lymphocytes in BALF of the asthmatic mice. The morphological changes and collagen deposition of airway were also reduced by Rh1 in asthmatic mice. The increase of Eotaxin, IL-4, IL-5, IL-13, and IL-33 and the decrease of IL-12 and IFN-γ in both BALF and serum of OVA exposed mice were reversed by Rh1. Rh1 attenuates OVA-induced asthma in the mice model by regulating Th1/Th2 cytokines balance.

A review of epigenetic changes in asthma: methylation and acetylation

Several studies show that childhood and adulthood asthma and its symptoms can be modulated through epigenetic modifications. Epigenetic changes are inheritable modifications that can modify the gene expression without changing the DNA sequence. The most common epigenetic alternations consist of DNA methylation and histone modifications. How these changes lead to asthmatic phenotype or promote the asthma features, in particular by immune pathways regulation, is an understudied topic. Since external effects, like exposure to tobacco smoke, air pollution, and drugs, influence both asthma development and the epigenome, elucidating the role of epigenetic changes in asthma is of great importance. This review presents available evidence on the epigenetic process that drives asthma genes and pathways, with a particular focus on DNA methylation, histone methylation, and acetylation. We gathered and assessed studies conducted in this field over the past two decades. Our study examined asthma in different aspects and also shed light on the limitations and the important factors involved in the outcomes of the studies. To date, most of the studies in this area have been carried out on DNA methylation. Therefore, the need for diagnostic and therapeutic applications through this molecular process calls for more research on the histone modifications in this disease.

Spontaneous resolution of atopic dermatitis incidental to participation in benralizumab clinical trial for severe, uncontrolled asthma: a case report

BACKGROUND

T cell-mediated eosinophilia is associated with numerous conditions-including atopic dermatitis, food allergies, and asthma-collectively known as the "atopic march." Benralizumab is a recombinant, humanized, afucosylated monoclonal antibody directed against the ⍺ chain of the eosinophil cell surface receptor IL-5R. Benralizumab treatment causes near-complete depletion of circulating eosinophils and was approved in 2017 for add-on, maintenance treatment of severe asthma with an eosinophilic phenotype, based on the results of the CALIMA and SIROCCO pivotal trials. Benralizumab is not currently approved for the treatment of eosinophilic conditions besides asthma; however, during the CALIMA trial, spontaneous resolution of atopic dermatitis was observed in a patient, concurrent with reduction in her asthma symptoms.

CASE PRESENTATION

In January 2015, a 14-year-old Asian girl with severe, uncontrolled asthma was enrolled in CALIMA. The patient's baseline eosinophil blood count was 1200 cells/μL, her pre-bronchodilator forced expiratory volume in 1 second (FEV₁) was 1.9 L and FEV₁/forced vital capacity (FVC) ratio was 71.4%, and her post-bronchodilator FEV₁ was 3.2 L (FEV₁/FVC of 115.9%). Her overall baseline asthma symptom score was 3.9 and her asthma exacerbation rate in the prior year was 4. She also displayed a pronounced, pruritic, chronic, inflammatory rash consistent with atopic dermatitis across her face. The investigator was blinded to the patient's treatment group during treatment; however, her asthma symptoms diminished over the course of the study (FEV₁ at 56 weeks, 3.01 L/110.5% (pre) and 3.25 L/119.3% (post); overall asthma symptom score 2.1; one influenza-associated exacerbation). Furthermore, her atopic dermatitis symptoms resolved spontaneously within the first 5 months of the study. After unblinding, the patient was confirmed to have been randomized to an active treatment arm, and her blood eosinophil count had dropped below the limit of detection after the first study dose.

CONCLUSIONS

Given the potential shared mechanisms between eosinophilic asthma and atopic dermatitis, it is plausible that benralizumab-induced eosinopenia factored into the resolution of the patient's atopic dermatitis. Further clinical studies are warranted to determine whether benralizumab or other drugs targeted against IL-5/IL-5R may be useful in managing multiple conditions associated with eosinophilia.

Cytokine levels in children and adults with wheezing and asthma show specific patterns of variability over time

Levels of cytokines are used for in-depth characterization of patients with asthma; however, the variability over time might be a critical confounder. To analyze the course of serum cytokines in children, adolescents and adults with asthma and in healthy controls and to propose statistical methods to control for seasonal effects. Of 532 screened subjects, 514 (91·5%) were included in the All Age Asthma Cohort (ALLIANCE). The cohort included 279 children with either recurrent wheezing bronchitis (more than two episodes) or doctor-diagnosed asthma, 75 healthy controls, 150 adult asthmatics and 31 adult healthy controls. Blood samples were collected and 25 μl serum was used for analysis with the Bio-Plex Pr human cytokine 27-Plex assay. Mean age, body mass index and gender in the three groups of wheezers, asthmatic children and adult asthmatics were comparable to healthy controls. Wheezers (34·5%), asthmatic children (78·7%) and adult asthmatics (62·8%) were significantly more often sensitized compared to controls (4·5, 22 and 22·6%, respectively). Considering the entire cohort, interleukin (IL)-1ra, IL-4, IL-9, IL-17, macrophage inflammatory protein (MIP)-1- α and tumor necrosis factor (TNF)- α showed seasonal variability, whereas IL-1β, IL-7, IL-8, IL-13, eotaxin, granulocyte colony-stimulating factor (G-CSF), interferon gamma-induced protein (IP)-10, MIP-1 β and platelet-derived growth factor (PDGF)-BB did not. Significant differences between wheezers/asthmatics and healthy controls were observed for IL-17 and PDGF-BB, which remained stable after adjustment for the seasonality of IL-17. Seasonality has a significant impact on serum cytokine levels in patients with asthma. Because endotyping has achieved clinical importance to guide individualized patient-tailored therapy, it is important to account for seasonal effects.

Carvone Enantiomers Differentially Modulate IgE-Mediated Airway Inflammation in Mice

Carvone is a monoterpene found in nature in the form of enantiomers (S- and R-). While previous research has demonstrated the anti-inflammatory and anti-allergic effects of carvone, the influence of carvone enantiomeric composition on its anti-allergic activity remains to be investigated. This study aimed to evaluate the anti-allergic activity of carvone enantiomers in a murine model of airway allergic inflammation induced by sensitization and challenge with ovalbumin (OVA). The oral treatment with R-carvone or S-carvone 1 h before each challenge inhibited the number of leukocytes and eosinophils in the bronchoalveolar lavage (BAL). R-carvone inhibited leukocyte infiltration and mucus production in the lung, which was correlated with decreased production of OVA-specific IgE in the serum and increased concentrations of IL-10 in the BAL. On the other hand, the administration of S-carvone had little inhibitory effect on inflammatory infiltration and mucus production in the lung, which might be associated with increased production of IFN-γ in the BAL. When administered 1 h before each sensitization, both enantiomers inhibited eosinophil recruitment to the BAL but failed in decreasing the titers of IgE in the serum of allergic mice. Our data indicate that carvone enantiomers differentially modulated IgE-mediated airway inflammation in mice. In conclusion, unlike S-carvone, R-carvone has the potential to be used in anti-allergic drug development.

Chiropractic Therapy Modulated Gut Microbiota and Attenuated Allergic Airway Inflammation in an Immature Rat Model

Background

As a type of traditional Chinese massage, chiropractic therapy is applied to prevent and treat children with asthma in China. However, its mechanism of action is unclear. Allergic airway inflammation plays a key role in the occurrence and development of asthma, in which changes in gut microbiota are involved. The present study investigated the influence of chiropractic therapy on allergic airway inflammation (AAI) and gut microbiota in an immature rat model.

Material/Methods

Three-week-old male Sprague-Dawley rats were divided randomly into control (CN), AAI, and chiropractic (CP) groups. AAI and CP groups were sensitized and challenged with ovalbumin (OVA) to induce AAI. The CP group received chiropractic therapy during AAI modelling. AAI was assessed by cell counts in bronchoalveolar lavage fluid and HE staining of lung tissues. Plasma OVA-sIgE, IFN-γ, IL-4, and IL-10 levels were detected by ELISA. DNA extraction from feces samples was used for 16S rRNA gene sequencing and analyzed for gut microbiota by Quantitative Insights Into Microbial Ecology (QIIME).

Results

AAI group had significantly lower richness and diversity of gut microbiota along with Th2 response and allergic airway inflammation. Moreover, the AAI group had lower abundance of butyrate-producing bacterial taxa with more Lactobacillus. Chiropractic therapy significantly increased the richness and diversity of gut microbiota and increased butyrate-producing bacterial taxa and decreased Lactobacillus, along with attenuating Th2 response and allergic airway inflammation during AAI modelling.

Conclusions

Chiropractic therapy attenuated allergic airway inflammation and optimized gut microbiota in an immature rat model, which might promote the development of adult-like butyrogenic milieu, immunotolerance, and inflammation attenuation.

Pragmatic Markers in the Management of Asthma: A Real-World-Based Approach

Bronchial hyperreactivity, reversible airflow limitation and chronic airway inflammation characterize asthma pathophysiology. Personalized medicine, i.e., a tailored management approach, is appropriate for asthma management and is based on the identification of peculiar phenotypes and endotypes. Biomarkers are necessary for defining phenotypes and endotypes. Several biomarkers have been described in asthma, but most of them are experimental and/or not commonly available. The current paper will, therefore, present pragmatic biomarkers useful for asthma management that are available in daily clinical practice. In this regard, eosinophil assessment and serum allergen-specific IgE assay are the most reliable biomarkers. Lung function, mainly concerning forced expiratory flow at 25-755 of vital capacity (FEF_25-75), and nasal cytology may be envisaged as ancillary biomarkers in asthma management. In conclusion, biomarkers have clinical relevance in asthma concerning both the endotype definition and the personalization of the therapy.

A comparison of biologicals in the treatment of adults with severe asthma - real-life experiences

BACKGROUND

Anti-IgE (omalizumab) and anti-IL5/IL5R (reslizumab, mepolizumab and benralizumab) treatments are available for severe allergic and eosinophilic asthma. In these patients, studies have shown beneficial effects in oral corticosteroid use and exacerbations. The aim of this retrospective single-center study was to evaluate the effect of biological therapy on severe asthma and to compare different therapies.

METHODS

We collected and analysed results of anti-IL5/IL5R and anti-IgE therapies for asthma from January 2009 until October 2019 in specialized care. We compared number of exacerbations, asthma symptoms and use of per oral corticosteroids and antimicrobics because of asthma before and during biological therapy, and in a separate analysis need for per oral corticosteroids, antimicrobics or surgery due to upper respiratory tract diseases in asthmatics receiving biologicals. The analyses were done using the Chi square test, T-test or Mann-Whitney U -test, the Kruskall-Wallis test or the Wilcoxon test.

RESULTS

Of 64 patients, 40 used continuous per oral corticosteroid therapy prior to biological therapy. The mean daily dose of per oral corticosteroid was reduced in those with anti-IL5/IL5R therapy (- 3.0 mg, p = 0.02). The number of annual per oral corticosteroid courses decreased in both the anti-IL5/IL5R (- 2.8 courses, p < 0.05) and anti-IgE groups (- 1.3 courses, p < 0.05). The number of annual antibiotic courses (- 0.7 courses, p = 0.04) and total number of exacerbation events (- 4.4 events/year, p < 0.05) were reduced in the anti-IL5/IL5R group. In the 55 asthma patients analysed for upper respiratory tract findings, the results suggested a reduction in need for chronic rhinosinusitis surgery during biological therapy.

CONCLUSIONS

Results with biological therapies in this real-life clinical setting are comparable to those reported in clinical trials. Biological therapy reduces exacerbations and per oral corticosteroid use.

TRIAL REGISTRATION

NCT04158050, retrospectively registered 6.11.2019.

Bifidobacterium infantis Relieves Allergic Asthma in Mice by Regulating Th1/Th2

Background

Bifidobacteria are among the probiotics used in treating intestinal diseases and are rarely used for allergic asthma treatment. The present study investigated the mechanism of B. infantis in treating allergic asthma in mice.

Material/Methods

A total of 40 male Balb/c mice were randomized into control, ovalbumin (OVA), montelukast (Mon), and B. infantis (B10) groups, and allergic asthma was induced in the OVA, Mon, and B10 groups. Airway reactivity was measured on day 29 by methacholine at various doses. The numbers of total cells and inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted by blood cell counter and Diff-Quik staining. Hematoxylin-eosin (HE) staining was performed to observe inflammatory cell infiltration in lung tissues. Total IgE and OVA-specific IgE in serum were measured by ELISA. Mucin 5AC expression was detected by Western blot to evaluate airway obstruction. The levels of Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5, IL-13) cytokines in BALF and tissues were detected by ELISA and qRT-PCR, respectively.

Results

The mice in the OVA group had airway hyperreactivity, while the symptoms in the B10 group and Mon group were effectively relieved. B10 reduced the number of inflammatory cells in BALF as well as inflammatory cell infiltration in tissues. Moreover, the levels of total serum IgE, OVA-specific IgE, and Mucin 5AC were increased in the OVA group, but were reduced in the Mon group and B10 group. B. infantis increased the levels of Th1 cytokines and decreased those of Th2 cytokines.

Conclusions

B. infantis can reduce the infiltration of inflammatory cells induced by OVA-specific antibodies in mice. B. infantis has therapeutic effects on allergic asthma by promoting Th1 and inhibiting Th2 immune responses.

Descurainia sophia Ameliorates Eosinophil Infiltration and Airway Hyperresponsiveness by Reducing Th2 Cytokine Production in Asthmatic Mice

In Chinese medicine, Descurainia sophia is used to treat cough by removing the phlegm in asthma and inflammatory airway disease, but the mechanism is not clear. In this study, we evaluated whether D. sophia water extract (DSWE) can alleviate airway inflammation and airway hyperresponsiveness (AHR) in the lungs of a murine asthma model. Female BALB/c mice were divided into five groups: normal controls, ovalbumin (OVA)-sensitized asthmatic mice, and OVA-sensitized mice treated with DSWE (2, 4, 8 g/day) by intraperitoneal injection. After sacrificing the mice, serum was collected to detect OVA-specific antibodies by ELISA, as well as bronchoalveolar lavage fluid (BALF) to detect cytokine levels. We also detected gene expression and histopathologically evaluated the lungs of asthmatic mice. DSWE reduced AHR, goblet cell hyperplasia, eosinophil infiltration, and collagen aggregation in the lungs of asthmatic mice. DSWE also suppressed the gene expression of Th2-associated cytokines and chemokines in lung tissue and inhibited serum OVA-IgE and Th2-associated cytokine levels in the BALF of OVA-sensitized mice. Our findings suggest that DSWE is a powerful immunomodulator for ameliorated allergic reactions by suppressing Th2 cytokine expression in asthmatic mice.

Rubusoside alleviates the ovalbumin-induced mice allergic asthma by modulating the NF-κB activation

The anti-inflammatory and anti-asthmatic effects of rubusoside (Rbs) were investigated in the ovalbumin (OVA)-induced asthmatic mice, followed by effective attenuation of Rbs treatment on the airway hyperresponsiveness and reduction of inflammatory cells inside the bronchoalveolar lavage fluid (BALF). The mitigation of inflammatory infiltration as a result of Rbs treatment was histologically observed in these mice lungs. Rbs contributed to the decrease of inflammatory cytokines (TNF-α, IL-13, IL-6, IL-5, and IL-4) inside the BALF of mice with asthma. A decline of OVA-dependent IgE and IgG1 inside the serum was also noticed in these mice. Rbs was proved to enhance the mRNA level of Foxp3 inside the mice lung affected with asthma while decrease that of IL-17A, IL-23, and RORγt. NF-κB pathway activation elicited by OVA was suppressed by Rbs inside the pulmonary tissues. Rbs played significantly in the reduction of airway inflammation induced by OVA which with modulating NF-κB pathway activation. PRACTICAL APPLICATIONS: Simultaneous therapy with medicine and food is strategically significant for disease prevention and treatment in traditional Chinese medicine. Rbs is a diterpene glycoside isolated from Rubus suavissimus. The anti-inflammatory and anti-asthmatic mechanism dependent of Rbs need further study clinically. The goal of current investigation is to explore the anti-inflammatory as well as anti-asthmatic activity of Rbs in mouse models of OVA-induced experimental allergic asthma. Results of the present study are scientifically supportive for the use of Rbs as an adjunctive reagent for clinical treatment of allergic asthma.

The pharmacological management of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS)

Introduction: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a disease phenotype that shares T helper lymphocyte cell Th1/neutrophilic/non-Type-2 Inflammation pathways thought to be key in COPD and Th2/eosinophilic/Type-2 inflammatory pathways of asthma. The pharmacology of treating ACOS is challenging in severe circumstances.Areas covered: This review evaluates the stepwise treatment of ACOS using pharmacological treatments used in both COPD and asthma. The most common medications involve the same inhalers used to treat COPD and asthma patients. Advanced stepwise therapies for ACOS patients are based on patient characteristics and biomarkers. Very few clinical trials exist that focus specifically on ACOS patients.Expert opinion: After inhalers, advanced therapies including phosphodiesterase inhibitors, macrolides, N-acetylcysteine and statin therapy for those ACOS patients with a COPD appearance and exacerbations are available. In atopic ACOS patients with exacerbations, advanced asthma therapies (leukotriene receptor antagonists and synthesis blocking agents.) are used. ACOS patients with elevated blood eosinophil/IgE levels are considered for immunotherapy or therapeutic monoclonal antibodies blocking specific Th2/Type-2 interleukins or IgE. Symptom control, stabilization/improvement in pulmonary function and reduced exacerbations are the metrics of success. More pharmacological trials of ACOS patients are needed to better understand which patients benefit from specific treatments.Abbreviations: 5-LOi: 5-lipoxygenase inhibitor; ACOS: asthma - COPD overlap syndrome; B₂AR: Beta₂ adrenergic receptors; cAMP: cyclic adenosine monophosphate; cGMP: cyclic guanosine monophosphate; CI: confidence interval; COPD: chronic obstructive pulmonary disease; CRS : chronic rhinosinusitis; cys-LT: cysteinyl leukotrienes; DPI: dry powder inhaler; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: fixed-dose combination; FeNO: exhaled nitric oxide; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; GM-CSF: granulocyte-macrophage colony-stimulating factor; ICS : inhaled corticosteroids; IL: interleukin; ILC2: Type 2 innate lymphoid cells; IP₃: Inositol triphosphate; IRR: incidence rate ratio; KOLD: Korean Obstructive Lung Disease; LABA: long-acting B₂ adrenergic receptor agonist; LAMA: long-acting muscarinic receptor antagonist; LRA: leukotriene receptor antagonist; LT: leukotrienes; MDI: metered-dose inhalers; M_N: M-subtype muscarinic receptors; MRA: muscarinic receptor antagonist; NAC: N-acetylcysteine; NEB: nebulization; OR: odds ratio; PDE: phosphodiesterase; PEFR: peak expiratory flow rate; PGD2: prostaglandin D2; PRN: as needed; RR: risk ratio; SABA: short-acting B₂ adrenergic receptor agonist; SAMA: short-acting muscarinic receptor antagonist; SDMI: spring-driven mist inhaler; Th1: T helper cell 1 lymphocyte; Th2: T helper cell 2 lymphocytes; TNF-α: tumor necrosis factor alpha; US : United States.

Refractory asthma phenotyping based on immunoglobulin E levels and eosinophilic counts: A real life study

BACKGROUND

Asthma is an inflammatory heterogeneous disease with variable severity. The serum IgE level and Eosinophilic count have been used as biomarkers to define treatment strategies with biological agents in severe refractory asthma.

OBJECTIVE

The aim of this study is to determine the concurrence of high eosinophil count and elevated serum IgE levels in patients with severe refractory asthma.

METHODS

A retrospective cross-sectional real-life study was conducted on patients attending adult refractory asthma outpatient clinic between 2015 and 2018. Serum total IgE level and blood EOS count on matched dates with spirometry and Asthma Control Test (ACT) scores were collected. All data were obtained while patients were not on biological agents.

RESULTS

A total of 142 patients with severe refractory asthma were included. The mean age was 43 years, mean eosinophilic count 564 cells/μL and mean serum IgE levels of 520 IU/ml. There was a significant correlation between serum IgE level and eosinophilic count. Serum IgE and eosinophilic count were concurrently elevated in 110 patients (78%). The patients were further categorized into four subgroups. Group A: IgE 30-100 IU/mL and EOS 150-300 cells/μL (7.3%), Group B: IgE >100 IU/mL and EOS 150-300 cells/μL (19.1%), Group C: IgE 30-100 IU/mL and EOS >300 cells/μL (14.5%) and Group D: IgE >100 IU/mL, EOS >300 cells/μL (59.1%).

CONCLUSION

The majority of severe refractory asthma patients exhibits both elevated serum IgE level and eosinophilic counts.

Allergen immunotherapy as add-on to biologic agents

PURPOSE OF REVIEW

In this review, we sought to outline many of the recent evidences about the available clinical trials in which biologic agents [i.e. omalizumab (OMA)] were associated as add-on to allergen-specific immunotherapy (AIT).

RECENT FINDINGS

The available literature shows that OMA may be a valuable option as add-on to AIT for respiratory allergy, or food desensitization, especially in the escalation or build-up phases, in which adverse events are more commonly expected. The encouraging data for hymenoptera venom allergy remain limited to case reports, and no structured clinical trial is available.

SUMMARY

Over the past decade, studies of OMA used with AIT have shown promising results. Today, big randomized, double-blind, placebo-controlled trials are needed to better select those patients who would benefit from the addition of OMA (or other biologic agents) to AIT, as well as optimal dosing schedules, optimal duration of treatments and, finally, adequate evaluation about pharmacoeconomic aspects.

Current and future targeted therapies for severe asthma: Managing treatment with biologics based on phenotypes and biomarkers

Asthma is a respiratory disorder with considerable heterogeneity in aetiology, triggers, clinical characteristics and response to therapy. This diversity reflects different inflammatory pathways that can be subdivided into clinically similar categories called phenotypes, or pathogenically comparable groups called endotypes. In recent years, a great amount of research has been dedicated to the investigation and understanding of the heterogeneity of asthma pathophysiology and to the identification of treatable traits, biomarkers, mediators and therapeutic targets. Severe asthma is defined as an uncontrolled disease despite a maximal conventional therapeutic approach. While, to date, some target therapies showing improvements in lung function, asthma symptoms and a reduction of the annual rate of exacerbations in patients with severe asthma have been already approved, other treatments are currently being studied, specifically targeting Type 2 asthma. Further progress however, is still needed to tackle the molecular pathways for non-Type 2 asthma. The aim of the present narrative review is to discuss and examine the indication, mechanisms of action and therapeutic effects of currently available and emerging biologic agents for the treatment of severe asthma.

STAT6 inhibitory peptide reduces dendritic cell migration to the lymph nodes to control Th2 adaptive immunity in the mouse lung

Type 2 immunity in the lung is promoted through the release of innate cytokines, including TSLP, from lung structural cells. These cytokines drive Type 2 immunity in part through upregulation of OX40L on dendritic cells (DCs). DCs expressing OX40L are potent inducers of Th2 differentiation. We have shown previously that STAT6 inhibitory peptide (STAT6-IP), a cell penetrating peptide designed to inhibit the STAT6 transcription factor, reduces the induction of Th2 adaptive immunity in murine models of respiratory syncytial virus infection. Here we show that intranasal administration of STAT6-IP at the time of antigen priming with ovalbumin (OVA), in conjunction with the Nod2 agonist, MDP, reduced frequencies of CD11b⁺ lung DCs expressing OX40L. Consistent with these reductions, fewer activated DCs were localized to the lung draining lymph nodes in STAT6-IP-treated mice. Upon OVA challenge four weeks later, mice treated with STAT6-IP at the time of OVA/MDP priming did not develop airway hyperresponsiveness (AHR) and had reduced influx of eosinophils into the airways, mucus production, and serum OVA-specific IgE levels. Our findings provide evidence that the long-lasting inhibitory effects of STAT6-IP are due in part to inhibition of DC responses that drive maladaptive Th2 adaptive immunity and allergic airways disease.

Overlapping Effects of New Monoclonal Antibodies for Severe Asthma

Among the monoclonal antibodies (mAbs) developed for severe asthma treatment, three have already been marketed. Omalizumab was the first, more than 10 years ago; today, mepolizumab and reslizumab are also available in the European Union and the US. Omalizumab blocks free immunoglobulin E (IgE), mepolizumab and reslizumab block an interleukin (IL-5). In the near future, dupilumab and benralizumab are expected to emerge as two new alternatives. Benralizumab blocks the receptor for IL-5 (IL5-Rα) and has a direct cytotoxic effect on eosinophils, and dupilumab blocks the α-unit of the heterodimeric receptor for IL-4 and IL-13 (IL-4Rα); as a result, dupilumab can block both IL-4 and IL-13. The purpose of this manuscript is to present the pathophysiology of some immunological aspects of severe asthma, describe the adaptive and innate immunity arms as well as their interrelations (stressing the subordination of the adaptive arm to the innate arm), outline the pharmacologic effects of these mAbs, clarify the overlapping effects of the different mAbs, and discuss the differences between mAbs based on their target molecules. Based on the data presented, I propose omalizumab for patients with an allergic phenotype regardless of their peripheral eosinophilic count, and anti-IL-5 as an alternative in allergic patients with blood eosinophilia in which omalizumab has failed; anti-IL5 for patients with an eosinophilic phenotype and omalizumab as an alternative in patients in whom anti-IL5 fails and IgE ≥30 IU/mL (compassionate use). Omalizumab is also proposed for patients with severe chronic asthma allergic to seasonal allergens.

Immunoglobulin E as a Biomarker in Asthma

Asthma is a chronic disease that affects children and adults with significant morbidity and mortality. It is multifactorial, with genetic and environmental factors affecting the overall course of the disease. Both specific and total immunoglobulin (Ig)E can be used in specific phenotypes such as allergic asthma. Using IgE as a biomarker for asthma provides a target for management and treatment. Biotherapeutics continue to emerge as important advances in asthma treatment, and their effect on IgE and its biomarker role continue to be studied.

Role of epigenetics and DNA-damage in asthma

PURPOSE OF REVIEW

Although asthma is a common disease worldwide, its pathogenesis remains to be fully elucidated. There is increasing evidence of the interaction between epigenetics, DNA-damage, and environmental allergens in the development of asthma. In this review, we will focus on the role of epigenetics and DNA-damage in asthma.

RECENT FINDINGS

There is growing evidence of environmental allergens, particularly house dust mite, stimulating oxidative DNA damage in airway epithelial cells. The repair of this DNA damage has been implicated in the secretion of Th2 cytokines and the induction of allergic inflammation.

SUMMARY

Studies of the role of epigenetics, DNA-damage, and environmental allergens have begun to reveal the their complex interactions and their roles in the development of asthma. Further study in these areas may lead to novel prevention and treatment approaches.

Prospects for Monoclonal Antibody Therapy in Pediatric Asthma

PURPOSE OF REVIEW

The profile of biologic therapies for asthma is growing rapidly. We discuss how to match the proper pediatric patient with the most effective therapy.

RECENT FINDINGS

Currently available biologic therapies are most effective in patients with T2 high asthma. Newer drugs are currently being studied which target TSLP and interleukin 33. These newer drugs may provide options for asthmatics who do not respond to the current anti-IgE, anti-IL5, and anti-IL4/13 therapies. Asthma is a heterogeneous disease which can be driven by different inflammatory mediators in different patients. To select the most effective biologic therapy for a pediatric patient, the asthma phenotype must first be determined. The steep cost of biologics limits their use, which makes proper pairing of patient to therapy even more crucial. Presently, several therapies exist for T2 high asthma, but it is hoped in the future that development of drugs effective for T2 low asthmatics will be available as well.

Biological therapies for eosinophilic asthma

INTRODUCTION

Severe uncontrolled asthma is by definition refractory to traditional therapies or can be controlled only with therapies that have intolerable side effects. Monoclonal antibodies that target interleukin (IL)-5/IL-5Rα, IgE, and IL-4Rα have shown favorable results in clinical trials, including reductions in asthma exacerbations and other important clinical outcomes. These biological agents offer treatment alternatives to patients with uncontrolled severe eosinophilic asthma.

AREAS COVERED

This article reviews how the shifting emphasis toward identifying distinct asthma phenotypes has led to the approval of biological therapies that preferentially benefit patients with severe eosinophilic asthma. The clinical trials that led to the approval of these biologic treatments are discussed in detail.

EXPERT OPINION

Biologic therapies targeting the IL-5, IgE, IL-4/IL-13 signaling pathways have been successful in clinical trials in subjects with severe eosinophilic asthma. Some of these agents have also been successful regardless of peripheral blood eosinophil counts. These treatments have shown a relatively favorable safety profile in clinical trials, although long-term safety data for some of these agents are limited. Due to the high costs associated with these medications, they should be reserved for select patients where they yield a therapeutic and pharmacoeconomic advantage.

Protective Effects of Casticin From Vitex trifolia Alleviate Eosinophilic Airway Inflammation and Oxidative Stress in a Murine Asthma Model

Casticin has been isolated from Vitex trifolia and found to have anti-inflammatory and anti-tumor properties. We also previously discovered that casticin can reduce pro-inflammatory cytokines and ICAM-1 expression in inflammatory pulmonary epithelial cells. In the present study, we evaluated whether casticin reduced airway hyper-responsiveness (AHR), airway inflammation, and oxidative stress in the lungs of a murine asthma model and alleviated inflammatory and oxidative responses in tracheal epithelial cells. Female BALB/c mice were randomly divided into five groups: normal controls, ovalbumin (OVA)-induced asthma, and OVA-induced asthma treated with intraperitoneal injection of casticin (5 or 10 mg/kg) or prednisolone (5 mg/kg). Casticin reduced AHR, goblet cell hyperplasia, and oxidative responses in the lungs of mice with asthma. Mechanistic studies revealed that casticin attenuated the levels of Th2 cytokine in bronchoalveolar lavage fluids and regulated the expression of Th2 cytokine and chemokine genes in the lung. Casticin also significantly regulated oxidative stress and reduced inflammation in the lungs of mice with asthma. Consequently, inflammatory tracheal epithelial BEAS-2B cells treated with casticin had significantly suppressed levels of pro-inflammatory cytokines and eotaxin, and reduced THP-1 monocyte cell adherence to BEAS-2B cells via suppressed ICAM-1 expression. Thus, casticin is a powerful immunomodulator, ameliorating pathological changes by suppressing Th2 cytokine expression in mice with asthma.

Dose dependent effects of tadalafil and roflumilast on ovalbumin-induced airway hyperresponsiveness in guinea pigs

INTRODUCTION

Chronic obstructive diseases of airways associated with cough and/or airway smooth muscle hyperresponsiveness are usually treated with bronchodilating and anti-inflammatory drugs. Recently, selective phosphodiesterase (PDE) 4 inhibitors have been introduced into the therapy of chronic obstructive pulmonary disease. Several studies have demonstrated their ability to influence the airway reactivity and eosinophilic inflammation by increasing the intracellular cAMP concentrations also in bronchial asthma. Furthermore, the expression of PDE5 in several immune cells suggests perspectives of PDE5 inhibitors in the therapy of inflammation, as well.

PURPOSE

The aim of this study was to assess the dose-dependent effects of PDE4 and PDE5 inhibitors in allergic inflammation. Therefore, the effects of 7-days administration of PDE4 inhibitor roflumilast and PDE5 inhibitor tadalafil at two different doses in experimentally-induced allergic inflammation were evaluated.

MATERIALS AND METHODS

In the study, male adult guinea pigs were used. Control group was non-sensitized. Other animals were sensitized with ovalbumin over two weeks and thereafter treated intraperitoneally for 7 days with roflumilast or tadalafil (daily dose 0.5 mg/kg or 1.0 mg/kg b.w.), or with vehicle.

RESULTS

Both roflumilast and tadalafil reduced specific airway resistance after nebulization of histamine (marker of in vivo airway reactivity) at both doses used. The in vitro airway reactivity to cumulative doses of acetylcholine was significantly reduced for roflumilast at higher dose, predominantly in the lung tissue strips. Histamine-induced contractile responses were significantly influenced in both lung and tracheal tissue strips, predominantly at the higher doses. Tadalafil led to a decrease in contractile responses induced by both acetylcholine and histamine, with more significant effects in the lung tissue strips. These changes were associated with decreased numbers of circulating leukocytes and eosinophils and concentrations of interleukin (IL)-4, IL-5 and TNF-α in the lung homogenate.

CONCLUSIONS

The selective PDE4 and PDE5 inhibitors alleviated allergic airway inflammation, with more significant effects at the higher doses.

Novel glutathione-containing dry-yeast extracts inhibit eosinophilia and mucus overproduction in a murine model of asthma

BACKGROUND/OBSECTIVE

Airway inflammation by eosinophils, neutrophils and alveolar macrophages is a characteristic feature of asthma that leads to pathological subepithelial thickening and remodeling. Our previous study showed that oxidative stress in airways resulted in eosinophilia and epithelial apoptosis. The current study investigated whether glutathione-containing dry yeast extract (dry-YE) ameliorated eosinophilia, goblet cell hyperplasia and mucus overproduction.

MATERIALS/METHOD

This study employed 2 µg/mL lipopolysaccharide (LPS)- or 20 ng/mL eotaxin-1-exposed human bronchial epithelial cells and ovalbumin (OVA)-challenged mice. Dry-YE employed in this study contained a significant amount of glutathione (140 mg in 100 g dry yeast).

RESULTS

Human bronchial epithelial cell eotaxin-1 and mucin 5AC (MUC5AC) were markedly induced by the endotoxin LPS, which was dose-dependently attenuated by nontoxic dry-YE at 10-50 µg/mL. Moreover, dry-YE inhibited the MUC5AC induction enhanced by eotaxin-1, indicating that eotaxin-1-mediated eosinophilia may prompt the MUC5AC induction. Oral supplementation with 10-100 mg/kg dry-YE inhibited inflammatory cell accumulation in airway subepithelial regions with a reduction of lung tissue level of intracellular adhesion molecule-1. In addition, ≥ 50 mg/kg dry-YE diminished the lung tissue levels of eotaxin-1, eosinophil major basic protein and MUC5AC in OVA-exposed mice. Alcian blue/periodic acid schiff staining revealed that the dry-YE supplementation inhibited goblet cell hyperplasia and mucus overproduction in the trachea and bronchiolar airways of OVA-challenged mice.

CONCLUSIONS

Oxidative stress may be involved in the induction of eotaxin-1 and MUC5AC by endotoxin episode and OVA challenge. Dry-YE effectively ameliorated oxidative stress-responsive epithelial eosinophilia and mucus-secreting goblet cell hyperplasia in cellular and murine models of asthma.