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Respiratory Research May 2023The gut-lung axis is the concept that alterations of gut microbiota communities can influence immune function in the lungs. While studies have explored the relationship...
BACKGROUND
The gut-lung axis is the concept that alterations of gut microbiota communities can influence immune function in the lungs. While studies have explored the relationship between intestinal bacterial dysbiosis and asthma development, less is understood about the impact of commensal intestinal fungi on asthma severity and control and underlying mechanisms by which this occurs.
METHODS
Wild-type mice were treated with Cefoperazone to deplete gut bacteria and administered Candida albicans or water through gavage. Mice were then sensitized to house dust mite (HDM) and their lungs were analyzed for changes in immune response. Humans with asthma were recruited and stool samples were analyzed for Candida abundance and associations with asthma severity and control.
RESULTS
Mice with intestinal Candida dysbiosis had enhanced Th2 response after airway sensitization with HDM, manifesting with greater total white cell and eosinophil counts in the airway, and total IgE concentrations in the serum. Group 2 innate lymphoid cells (ILC2) were more abundant in the lungs of mice with Candida gut dysbiosis, even when not sensitized to HDM, suggesting that ILC2 may be important mediators of the enhanced Th2 response. These effects occurred with no detectable increased Candida in the lung by culture or rtPCR suggesting gut-lung axis interactions were responsible. In humans with asthma, enhanced intestinal Candida burden was associated with the risk of severe asthma exacerbation in the past year, independent of systemic antibiotic and glucocorticoid use.
CONCLUSIONS
Candida gut dysbiosis may worsen asthma control and enhance allergic airway inflammation, potentially mediated by ILC2. Further studies are necessary to examine whether microbial dysbiosis can drive difficult-to-control asthma in humans and to better understand the underlying mechanisms.
Topics: Humans; Mice; Animals; Immunity, Innate; Gastrointestinal Microbiome; Mycobiome; Dysbiosis; Lymphocytes; Lung; Asthma; Pyroglyphidae; Disease Models, Animal
PubMed: 37259076
DOI: 10.1186/s12931-023-02422-5 -
American Journal of Respiratory Cell... Jun 2022
Topics: Animals; Asthma; Cytokines; Epithelium; Inflammation; Pyroglyphidae; Sumoylation; Thymic Stromal Lymphopoietin
PubMed: 35364000
DOI: 10.1165/rcmb.2021-0558ED -
Frontiers in Immunology 2022Metal components of environmental PM2.5 are associated with the exacerbation of allergic diseases like asthma. In our recent hospital-based population study, exposure to...
BACKGROUND
Metal components of environmental PM2.5 are associated with the exacerbation of allergic diseases like asthma. In our recent hospital-based population study, exposure to vanadium is shown to pose a significant risk for current asthma, but the causal relationship and its underlying molecular mechanisms remain unclear.
OBJECTIVE
We sought to determine whether vanadium co-exposure can aggravate house dust mite (HDM)-induced allergic airway inflammation and remodeling, as well as investigate its related mechanisms.
METHODS
Asthma mouse model was generated by using either vanadium pentoxide (VO) or HDM alone or in combination, in which the airway inflammation and remodeling was investigated. The effect of VO co-exposure on HDM-induced epithelial-derived cytokine release and oxidative stress (ROS) generation was also examined by analyses. The role of ROS in VO co-exposure-induced cytokine release and airway inflammation and remodeling was examined by using inhibitors or antioxidant.
RESULTS
Compared to HDM alone, VO co-exposure exacerbated HDM-induced airway inflammation with increased infiltration of inflammatory cells and elevated levels of Th1/Th2/Th17 and epithelial-derived (IL-25, TSLP) cytokines in the bronchoalveolar lavage fluids (BALFs). Intriguingly, VO co-exposure also potentiated HDM-induced airway remodeling. Increased cytokine release was further supported by analysis in human bronchial epithelial cells (HBECs). Mechanistically, ROS, particularly mitochondrial-derived ROS, was significantly enhanced in HBECs after VO co-exposure as compared to HDM challenge alone. Inhibition of ROS with its inhibitor N-acetyl-L-cysteine (NAC) and mitochondrial-targeted antioxidant MitoTEMPO blocked the increased epithelial release caused by VO co-exposure. Furthermore, vitamin D as an antioxidant was found to inhibit VO co-exposure-induced increased airway epithelial cytokine release and airway remodeling.
CONCLUSIONS
Our findings suggest that vanadium co-exposure exacerbates epithelial ROS generation that contribute to increased allergic airway inflammation and remodeling.
Topics: Animals; Mice; Humans; Vanadium; Reactive Oxygen Species; Airway Remodeling; Antioxidants; Asthma; Cytokines; Inflammation; Pyroglyphidae; Dermatophagoides pteronyssinus; Oxidative Stress
PubMed: 36776398
DOI: 10.3389/fimmu.2022.1099509 -
Arhiv Za Higijenu Rada I Toksikologiju 2012Pyroglyphid mites are primarily associated with allergen exposure at home; hence the name house dust mites. However, we have found numerous studies reporting pyroglyhid... (Review)
Review
Pyroglyphid mites are primarily associated with allergen exposure at home; hence the name house dust mites. However, we have found numerous studies reporting pyroglyhid mite levels in public and occupational settings. This review presents the findings of house dust mite allergens (family Pyroglyphidae, species Dermatophagoides) as potential work-related risk factors and proposes occupations at risk of house dust mite-related diseases. Pyroglyphid mites or their allergens are found in various workplaces, but clinically relevant exposures have been observed in hotels, cinemas, schools, day-care centres, libraries, public transportation (buses, trains, taxies, and airplanes), fishing-boats, submarines, poultry farms, and churches. Here we propose a classification of occupational risk as low (occasional exposure to mite allergen levels up to 2 μg g(-1)), moderate (exposure between 2 μg g(-1) and 10 μg g(-1)), and high (exposure >10 μg g(-1)). The classification of risk should include factors relevant for indoor mite population (climate, building characteristics, and cleaning schedule). To avoid development or aggravation of allergies associated with exposure to house dust mites at work, occupational physicians should assess exposure risk at work, propose proper protection, provide vocational guidance to persons at risk and conduct pre-employment and periodic examinations to diagnose new allergy cases. Protection at work should aim to control dust mite levels at work. Measures may include proper interior design and regular cleaning and building maintenance.
Topics: Animals; Antigens, Dermatophagoides; Environmental Exposure; Humans; Hypersensitivity, Immediate; Occupational Diseases; Occupational Exposure; Pyroglyphidae
PubMed: 22548853
DOI: 10.2478/10004-1254-63-2012-2133 -
Scientific Reports Sep 2023Collagen, a major structural protein in mammalian tissues, is effective against skin wounds and osteoarthritis. Although bovine and porcine collagens have mainly been...
Collagen, a major structural protein in mammalian tissues, is effective against skin wounds and osteoarthritis. Although bovine and porcine collagens have mainly been used, several potential risks of mammalian collagen have led to the use of fish collagen (FC) as an alternative. FC and its peptides are used as common cosmeceutical products because of their antihypertensive, anti-bacterial, and antioxidant activities. Despite the effects of FC on wrinkle reduction, UV-protection, and wound healing, the relationship between FC and atopic dermatitis (AD) has not yet been reported. Therefore, we investigated the anti-AD effects of FC against house dust mite (Dermatophagoides farinae, HDM)-induced AD in NC/Nga mice and TNF-α/IFN-γ-stimulated HaCaT keratinocytes. FC alleviated AD apparent symptoms, such as dermatitis score, transepidermal water loss, epidermal thickness, and mast cell infiltration upon declining pro-inflammatory cytokines and mediators, IL-6, IL-5, IL-13, TSLP, and TNF-α. The skin barrier protein, filaggrin, was also recovered by FC administration in vivo and in vitro. Immune response and skin barrier dysfunction are both mitigated by three routes of FC administration: oral, topical, and both routes via the regulation of IκB, MAPKs, and STATs pathways. In summary, FC could be a potential therapeutic agent for AD by regulating immune balance and skin barrier function.
Topics: Swine; Animals; Cattle; Mice; Pyroglyphidae; Tumor Necrosis Factor-alpha; Dermatophagoides pteronyssinus; Keratinocytes; Collagen; Dermatitis, Atopic; Fishes; Mammals
PubMed: 37689763
DOI: 10.1038/s41598-023-41831-w -
The Cochrane Database of Systematic... Jun 2013Humidity control measures in the home environment of patients with asthma have been recommended, since a warm humid environment favours the growth of house dust mites.... (Review)
Review
BACKGROUND
Humidity control measures in the home environment of patients with asthma have been recommended, since a warm humid environment favours the growth of house dust mites. However, there is no consensus about the usefulness of these measures.
OBJECTIVES
To study the effect of dehumidification of the home environment on asthma control.
SEARCH METHODS
The clinical trials registers of the Cochrane Collaboration and Cochrane Airways Group were searched. Searches were current as of March 2013.
SELECTION CRITERIA
Randomised controlled trials on the use of humidity control measures in the home environment of patients with asthma were evaluated for inclusion.
DATA COLLECTION AND ANALYSIS
Data were extracted independently using a pre-designed data extraction form by two review authors.
MAIN RESULTS
A second trial has been added for the 2013 update of this review. The original open-label trial compared an intervention consisting of mechanical ventilation heat recovery system with or without high efficiency vacuum cleaner fitted in 40 homes of patients with asthma who had positive tests for sensitivity to house dust mite. The new double-blind trial also compared a mechanical ventilation heat recovery system with a placebo machine in the homes of 120 adults with allergy to house dust mite. The new trial, which was at low risk of bias, showed no significant difference in morning peak flow (mean difference (MD) 13.59; 95% confidence interval (CI) -2.66 to 29.84), which was the primary outcome of the trial. However, there was a statistically significant improvement in evening peak flow only (MD 24.56; 95% CI 8.97 to 40.15). There was no significant difference in quality of life, rescue medication, requirement for oral corticosteroids, visits to the GP, emergency department (ED) or hospitalisations for asthma. There was no significant difference in the house dust mite count and the antigen levels in the new trial, in contrast to the previous trial.
AUTHORS' CONCLUSIONS
Evidence on clinical benefits of dehumidification using mechanical ventilation with dehumidifiers remains scanty, and the addition of a new double blind trial to this review does not indicate significant benefit in most measure of control of asthma from such environmental interventions.
Topics: Animals; Asthma; Chronic Disease; Environment, Controlled; Humans; Humidity; Pyroglyphidae; Randomized Controlled Trials as Topic; Ventilation
PubMed: 23760885
DOI: 10.1002/14651858.CD003563.pub2 -
The Journal of Allergy and Clinical... Jul 2015The house dust mite (HDM) is a major perennial allergen source and a significant cause of allergic rhinitis and allergic asthma. However, awareness of the condition... (Review)
Review
The house dust mite (HDM) is a major perennial allergen source and a significant cause of allergic rhinitis and allergic asthma. However, awareness of the condition remains generally low. This review assesses the links between exposure to HDM, development of the allergic response, and pathologic consequences in patients with respiratory allergic diseases. We investigate the epidemiology of HDM allergy to explore the interaction between mites and human subjects at the population, individual, and molecular levels. Core and recent publications were identified by using "house dust mite" as a key search term to evaluate the current knowledge of HDM epidemiology and pathophysiology. Prevalence data for HDM allergen sensitization vary from 65 to 130 million persons in the general population worldwide to as many as 50% among asthmatic patients. Heterogeneity of populations, terminology, and end points in the literature confound estimates, indicating the need for greater standardization in epidemiologic research. Exposure to allergens depends on multiple ecological strata, including climate and mite microhabitats within the domestic environment, with the latter providing opportunity for intervention measures to reduce allergen load. Inhaled mite aeroallergens are unusually virulent: they are able to activate both the adaptive and innate immune responses, potentially offering new avenues for intervention. The role of HDM allergens is crucial in the development of allergic rhinitis and asthma, but the translation of silent sensitization into symptomatic disease is still incompletely understood. Improved understanding of HDMs, their allergens, and their microhabitats will enable development of more effective outcomes for patients with HDM allergy.
Topics: Animals; Antigens, Dermatophagoides; Climate; Ecosystem; Europe; Humans; Immunization; Prevalence; Pyroglyphidae; Respiratory Hypersensitivity
PubMed: 25457152
DOI: 10.1016/j.jaci.2014.10.012 -
International Journal of Molecular... May 2023Ceramides are epidermal lipids important for normal skin barrier function. Reduced Ceramide content is associated with atopic dermatitis (AD). House dust mite (HDM) has...
Ceramides are epidermal lipids important for normal skin barrier function. Reduced Ceramide content is associated with atopic dermatitis (AD). House dust mite (HDM) has been localized in AD skin where it plays an exacerbator role. We set to examine the impact of HDM on skin integrity and the effect of three separate Ceramides (AD™, DS, Y30) on HDM-induced cutaneous damage. The effect was tested in vitro on primary human keratinocytes and ex vivo on skin explants. HDM (100 μg/mL) decreased the expression of adhesion protein E-cadherin, supra-basal (K1, K10) and basal (K5, K14) keratins and increased matrix metallopeptidase (MMP)-9 activity. The presence of Ceramide AD™ in topical cream inhibited HDM-induced E-cadherin and keratin destruction and dampened MMP-9 activity ex vivo which was not seen for the control cream or cream containing DS or Y30 Ceramides. The efficacy of Ceramide AD™ was tested in a clinical setting on moderate to very dry skin (as surrogate for environment-induced skin damage). When applied topically for 21 days, Ceramide AD™ significantly reduced transepidermal water loss (TEWL) in patients with very dry skin compared to their TEWL baseline data. Our study demonstrates Ceramide AD™ cream to be effective in restoring skin homeostasis and barrier function in damaged skin and warrants testing in larger clinical trials for possible treatment of AD and xerosis.
Topics: Animals; Humans; Ceramides; Pyroglyphidae; Skin; Dermatitis, Atopic; Epidermis; Dermatophagoides pteronyssinus; Keratins; Emollients
PubMed: 37298186
DOI: 10.3390/ijms24119234 -
Current Allergy and Asthma Reports Jun 2020To critically review the evidence in favor or against the use of house dust mite (HDM) allergen avoidance measures in patients with asthma. (Review)
Review
PURPOSE OF REVIEW
To critically review the evidence in favor or against the use of house dust mite (HDM) allergen avoidance measures in patients with asthma.
RECENT FINDINGS
Systematic reviews and meta-analyses suggested no positive effect of mite allergen avoidance strategies on asthma outcomes, resulting in a lack of consensus regarding the utility of these measures. However, such analyses have a number limitations and might not be the most adequate tool to evaluate current evidence and to derive clinical recommendations regarding mite allergen avoidance in asthmatic patients. We should not disproportionately rely on the results of meta-analyses and systematic reviews to inform clinical practice and asthma guidelines in this area. Recent high-quality evidence from randomized controlled trial in children confirmed that mite allergen-impermeable bed encasings reduce emergency hospital attendance with acute severe asthma exacerbations. Until better evidence is available, we suggest that physicians should adopt a pragmatic approach to mite allergen avoidance and advise sensitized patients to implement a multifaceted set of measures to achieve as great a reduction in exposure as possible. Potential predictors of positive response (e.g., patient's sensitization and exposure status) can pragmatically be evaluated using the size of skin test wheal or the titer of allergen-specific IgE. Finally, the intervention should be started as early as possible.
Topics: Allergens; Animals; Asthma; Humans; Pyroglyphidae; Skin Tests
PubMed: 32561997
DOI: 10.1007/s11882-020-00948-y -
Allergy Nov 2015Allergen immunotherapy is a treatment modality which can be applied using different vaccines. The aim of this study was to quantify and compare the allergen content of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Allergen immunotherapy is a treatment modality which can be applied using different vaccines. The aim of this study was to quantify and compare the allergen content of different house dust mites (HDM)' sublingual treatments and to review the evidence on their efficacy.
METHODS
Five sublingual allergen immunotherapy (SLIT) products were ordered and purchased at an ordinary pharmacy and masked for blinding before the study was started. Detection of Dermatophagoides pteronyssinus and Dermatophagoides farinae allergens Der p 1, Der f 1, Der p 2 and Der f 2 was carried out by immunoblotting and fluorescent multiplex. A literature search for meta-analyses and systematic reviews that included SLIT-HDM products was performed.
RESULTS
Der p 1 concentrations ranged from 0.6 to 14.5 μg/ml; similar figures were found for Der f 1 that ranged from 0.2 to 12.4 μg/ml. Der p 2+ Der f 2 ranged from 0.2 to 1.5 μg/ml. Data on efficacy are scarce for most of the five products.
CONCLUSIONS
Substantial variations regarding allergen content were found among these five SLIT-HDM products. Therefore, it can be necessary to guarantee the quality of the SLIT-HDM products and to demonstrate their effectiveness before they are marketed. It seems necessary, for the moment, to take into account these characteristics of the products before prescribing.
Topics: Allergens; Animals; Antigens, Dermatophagoides; Humans; Hypersensitivity; Pyroglyphidae; Sublingual Immunotherapy; Treatment Outcome; Vaccines
PubMed: 26185961
DOI: 10.1111/all.12694