Allergic asthma: influence of genetic and environmental factors

Association between bronchial asthma and TSLP gene polymorphism: a systematic review and meta-analysis

Aims

This study entails an association between bronchial asthma and common single nucleotide polymorphisms (SNPs) in thymic stromal lymphopoietin (TSLP) gene; rs2289278, rs3806933, rs2289276, and rs1837253.

Methods

The databases of PubMed, Embase, Web of Science, and Google Scholar were searched for studies reporting TSLP polymorphisms and asthma from inception to January 2022. Hardy-Weinberg equilibriums (HWE) for each polymorphism of the control group were checked using the χ 2 test. The association was estimated by means of odds ratio (OR) with 95% CI in both dominant and recessive modes of inheritance, respectively.

Results

Altogether, 11 studies with 3121 asthma cases and 3041 healthy controls were added. Results from six studies showed that the SNP rs2289278 had a protective role in asthma development (OR=0.65, 95% CI: 0.44-0.97, P=0.04). Pooling of four studies showed that the SNP rs3806933 had higher odds of developing asthma (OR=1.32, 95% CI:1.14-1.54, P<0.01). However, the SNP rs2289276 and rs1837253 showed no significant association. From the subgroup analysis, SNPs rs2289278 and rs1837253 were protective against the development of asthma in Asia. However, SNP rs2289276 showed a risk association in Asia and in adults.

Conclusion

This meta-analysis shows that the SNP rs2289278 has a protective effect on the development of asthma; whereas rs3806933 has a risk of asthma. Additionally, this study adds genomic-based support to the recent FDA approval of tezepelumab, an anti-TSLP agent.

High humidity and NO2 co-exposure exacerbates allergic asthma by increasing oxidative stress, inflammatory and TRP protein expressions in lung tissue

Allergic asthma is a chronic inflammatory airway disease with a high mortality rate and a rapidly increasing prevalence in recent decades that is closely linked to environmental change. Previous research found that high humidity (HH) and the traffic-related air pollutant NO2 both aggregated allergic asthma. Their combined effect and mechanisms on asthma exacerbation, however, are unknown. Our study aims to toxicologically clarify the role of HH (90%) and NO2 (5 ppm) on allergic asthma. Ninety male Balb/c mice were randomly assigned to one of six groups (n = 15 in each): saline control, ovalbumin (OVA)-sensitized, OVA + HH, OVA + NO2, OVA + HH + NO2, and OVA + HH + NO2+Capsazepine (CZP). After 38 days of treatment, the airway function, pathological changes in lung tissue, blood inflammatory cells, and oxidative stress and inflammatory biomarkers were comprehensively assessed. Co-exposure to HH and NO2 exacerbated histopathological changes and airway hyperresponsiveness, increased IgE, oxidative stress markers malonaldehyde (MDA) and allergic asthma-related inflammation markers (IL-1β, TNF-α and IL-17), and upregulated the expressions of the transient receptor potential (TRP) ion channels (TRPA1, TRPV1 and TRPV4). Our findings show that co-exposure to HH and NO2 disrupted the Th1/Th2 immune balance, promoting allergic airway inflammation and asthma susceptibility, and increasing TRPV1 expression, whereas CZP reduced TRPV1 expression and alleviated allergic asthma symptoms. Thus, therapeutic treatments that target the TRPV1 ion channel have the potential to effectively manage allergic asthma.

Identification of mitochondria-related biomarkers in childhood allergic asthma

BACKGROUND

The mechanism of mitochondria-related genes (MRGs) in childhood allergic asthma (CAS) was unclear. The aim of this study was to find new biomarkers related to MRGs in CAS.

METHODS

This research utilized two CAS-related datasets (GSE40888 and GSE40732) and extracted 40 MRGs from the MitoCarta3.0 Database. Initially, differential expression analysis was performed on CAS and control samples in the GSE40888 dataset to obtain the differentially expressed genes (DEGs). Differentially expressed MRGs (DE-MRGs) were obtained by overlapping the DEGs and MRGs. Protein protein interactions (PPI) network of DE-MRGs was created and the top 10 genes in the degree ranking of Maximal Clique Centrality (MCC) algorithm were defined as feature genes. Hub genes were obtained from the intersection genes from the Least absolute shrinkage and selection operator (LASSO) and EXtreme Gradient Boosting (XGBoost) algorithms. Additionally, the expression validation was conducted, functional enrichment analysis, immune infiltration analysis were finished, and transcription factors (TFs)-miRNA-mRNA regulatory network was constructed.

RESULTS

A total of 1505 DEGs were obtained from the GSE40888, and 44 DE-MRGs were obtained. A PPI network based on these 44 DE-MRGs was created and revealed strong interactions between ADCK5 and MFN1, BNIP3 and NBR1. Four hub genes (NDUFAF7, MTIF3, MRPS26, and NDUFAF1) were obtained by taking the intersection of genes from the LASSO and XGBoost algorithms based on 10 signature genes which obtained from PPI. In addition, hub genes-based alignment diagram showed good diagnostic performance. The results of Gene Set Enrichment Analysis (GSEA) suggested that hub genes were closely related to mismatch repair. The B cells naive cells were significantly expressed between CAS and control groups, and MTIF3 was most strongly negatively correlated with B cells naive. In addition, the expression of MTIF3 and MRPS26 may have influenced the inflammatory response in CAS patients by affecting mitochondria-related functions. The quantitative real-time polymerase chain reaction (qRT‒PCR) results showed that four hub genes were all down-regulated in the CAS samples.

CONCLUSION

NDUFAF7, MTIF3, MRPS26, and NDUFAF1 were identified as an MRGs-related biomarkers in CAS, which provides some reference for further research on CAS.

Preparation and in vivo evaluation of nano sized cubosomal dispersion loaded with Ruta graveolens extracts as a novel approach to reduce asthma-mediated lung inflammation

Asthma is a chronic disease affecting people of all ages. Asthma medications are associated with adverse effects restricting their long-term usage, demanding newer alternative therapies. This study aimed to investigate the anti-asthmatic properties of Ruta graveolens extract and its prepared nano-cubosomal dispersion (Ruta-ND). Firstly, the R. graveolens methanolic extract exhibited higher anti-inflammatory activity on Lipopolysaccharide (LPS)-activated BEAS-2B cells. To ensure best bioavailability and hence best cellular uptake, R. graveolens extract was loaded in nano-cubosomal dispersion (ND). Then, the anti-asthmatic effects of Ruta extract and ND were simultaneously evaluated in rats' model with ovalbumin-induced allergic asthma. R. graveolens extract and Ruta-ND subsided asthma score and improved lung function by restoring FEV1/FVC ratio to the expected values in control rats. Also, it showed strong antioxidant and anti-inflammatory activities manifested by lowering levels of malondialdehyde (MDA), IL-4, IL-7, TGF-β, and Ig-E, and increasing levels of superoxide dismutase (SOD) and INF-γ in bronchoalveolar lavage fluid. Our research findings also indicate autophagy induction and apoptosis inhibition by Ruta extract and Ruta-ND. Finally, the HPLC MS/MS phytochemical profiling of R. graveolens extract evident production of various alkaloids, flavonoids, coumarins, and other phenolics with reported pharmacological properties corresponding to/emphasize our study findings. In conclusion, R. graveolens exhibited promise in managing Ova-induced allergic asthma and could be developed as an alternative anti-allergic asthma drug.

Public perceptions of genomic studies and hereditary diseases in Aari community, South Omo Zone, Ethiopia

BACKGROUND

Genetic and genomic research is revolutionizing precision medicine; however, addressing ethical and cultural aspects is crucial to ensure ethical conduct and respect for community values and beliefs. This study explored the beliefs, perceptions and concerns of the Aari community in South Ethiopia regarding genetic concepts, hereditary diseases and ethical research practices related to sample collection, storage and sharing.

METHODS

In-depth interviews and focus group discussions were conducted with community elders, health officials, tuberculosis patients and apparently healthy individuals. Data were thematically analysed using MAXQDA software.

RESULTS

Participants identified diseases such as podoconiosis, leprosy, goitre and epilepsy as hereditary and perceived some as 'curses' due to generational impact and social stigma. Disease susceptibility was attributed to divine intervention or factors such as malnutrition and sanitation. Although hereditary diseases were considered unavoidable, in some cases environmental factors were acknowledged. Participants shared personal examples to demonstrate inheritance concepts. Blood held cultural significance, and concerns about its potential misuse resulted in scepticism towards giving samples.

CONCLUSIONS

This study emphasizes the significance of comprehending local beliefs and perceptions and stresses the need to establish effective communication, build trust and address underlying causes of hesitancy to improve recruitment and ensure ethical conduct.

Socioeconomic and environmental determinants of asthma prevalence: a cross-sectional study at the U.S. County level using geographically weighted random forests

BACKGROUND

Some studies have established associations between the prevalence of new-onset asthma and asthma exacerbation and socioeconomic and environmental determinants. However, research remains limited concerning the shape of these associations, the importance of the risk factors, and how these factors vary geographically.

OBJECTIVE

We aimed (1) to examine ecological associations between asthma prevalence and multiple socio-physical determinants in the United States; and (2) to assess geographic variations in their relative importance.

METHODS

Our study design is cross sectional based on county-level data for 2020 across the United States. We obtained self-reported asthma prevalence data of adults aged 18 years or older for each county. We applied conventional and geographically weighted random forest (GWRF) to investigate the associations between asthma prevalence and socioeconomic (e.g., poverty) and environmental determinants (e.g., air pollution and green space). To enhance the interpretability of the GWRF, we (1) assessed the shape of the associations through partial dependence plots, (2) ranked the determinants according to their global importance scores, and (3) mapped the local variable importance spatially.

RESULTS

Of the 3059 counties, the average asthma prevalence was 9.9 (standard deviation ± 0.99). The GWRF outperformed the conventional random forest. We found an indication, for example, that temperature was inversely associated with asthma prevalence, while poverty showed positive associations. The partial dependence plots showed that these associations had a non-linear shape. Ranking the socio-physical environmental factors concerning their global importance showed that smoking prevalence and depression prevalence were most relevant, while green space and limited language were of minor relevance. The local variable importance measures showed striking geographical differences.

CONCLUSION

Our findings strengthen the evidence that socio-physical environments play a role in explaining asthma prevalence, but their relevance seems to vary geographically. The results are vital for implementing future asthma prevention programs that should be tailor-made for specific areas.

Cordyceps militaris polysaccharide alleviates ovalbumin-induced allergic asthma through the Nrf2/HO-1 and NF-κB signaling pathways and regulates the gut microbiota

Polysaccharides, as one of the main types of bioactive components of Cordyceps militaris, have anti-allergic asthma effects. Herein, an ovalbumin-induced allergic asthma mouse model was established to assess the potential mechanisms of the separated and purified Cordyceps militaris polysaccharide (CMP). CMP is an α-pyranose with a molecular weight of 15.94 kDa that consists of Glc, Man, Gal, Xyl, Ara and GlcA in a molar ratio of 81.25:21.96:13.88:3.92:3.58:1.00. CMP improved inflammatory cytokine levels, alleviated the histopathological changes in the lung and intestinal tissues, regulated the expression of mRNA and proteins related to oxidative stress and inflammatory pathways, reversed gut dysbiosis at the phylum and family levels and improved microbiota function in allergic asthma mice. Moreover, it was found that the levels of inflammatory cytokines in lung tissue of mice were significantly correlated with some intestinal microbial communities. Overall, CMP improved oxidative stress and the inflammatory response in allergic asthma mice by regulating the Nrf2/HO-1 and NF-κB signaling pathways, which may be closely correlation with maintaining the stability of the gut microbiota.

A four-part guide to lung immunology: Invasion, inflammation, immunity, and intervention

Lungs are important respiratory organs primarily involved in gas exchange. Lungs interact directly with the environment and their primary function is affected by several inflammatory responses caused by allergens, inflammatory mediators, and pathogens, eventually leading to disease. The immune architecture of the lung consists of an extensive network of innate immune cells, which induce adaptive immune responses based on the nature of the pathogen(s). The balance of immune responses is critical for maintaining immune homeostasis in the lung. Infection by pathogens and physical or genetic dysregulation of immune homeostasis result in inflammatory diseases. These responses culminate in the production of a plethora of cytokines such as TSLP, IL-9, IL-25, and IL-33, which have been implicated in the pathogenesis of several inflammatory and autoimmune diseases. Shifting the balance of Th1, Th2, Th9, and Th17 responses have been the targets of therapeutic interventions in the treatment of these diseases. Here, we have briefly reviewed the innate and adaptive i3mmune responses in the lung. Genetic and environmental factors, and infection are the major causes of dysregulation of various functions of the lung. We have elaborated on the impact of inflammatory and infectious diseases, advances in therapies, and drug delivery devices on this critical organ. Finally, we have provided a comprehensive compilation of different inflammatory and infectious diseases of the lungs and commented on the pros and cons of different inhalation devices for the management of lung diseases. The review is intended to provide a summary of the immunology of the lung, with an emphasis on drug and device development.

Ameliorative Effect of Imperatorin on Dermatophagoides pteronyssinus-Induced Allergic Asthma by Suppressing the Th2 Response in Mice

Imperatorin is a furanocoumarin derivative and an effective ingredient in several Chinese medicinal herbs. It has favorable expectorant, analgesic, and anti-inflammatory effects. In this study, we investigated whether imperatorin has protective effects against Dermatophagoides pteronyssinus (Der p)-induced asthma in mice. Lung and bronchial tissues were histopathologically examined through hematoxylin–eosin staining. The concentrations of immunoglobin E (IgE), IgG1, IgG2a in serum and those of T helper 1 (Th1) and two cytokines and eosinophil-activated chemokines in bronchoalveolar lavage fluid (BALF) were detected using an enzyme immunoassay. Histological examination revealed that imperatorin reduced inflammatory cell infiltration, mucus hypersecretion, and endothelial cell hyperplasia. The examination also indicated that imperatorin could reduce the inflammatory cell count in BALF as well as IgE and IgG1 expression in serum, but IgG2a expression was significantly increased. Imperatorin reduced the production of interleukin (IL)-4, IL-5, and IL-13 by Th2, promoted the production of interferon-γ and IL-12 by Th1, and increased the production of IL-10 in bronchoalveolar lavage fluid. These findings suggest that imperatorin has a considerable anti-inflammatory effect on Der p-induced allergic asthma in mice.

Association of Interleukin 6 and Interleukin 8 genes polymorphisms with house dust mite-induced nasal-bronchial allergy in a sample of Indian patients

Background

Genetic background of nasal-bronchial allergy (NBA) is well documented. House Dust Mites (HDMs) are reported to elicit NBA symptoms. Susceptibility to HDM sensitization varies considerably from person to person. Interleukin 6 (IL 6) and Interleukin 8 (IL 8) are studied previously for genetic association with several diseases. To the best of our knowledge, the genetic association of HDM-induced NBA has not been largely reported from India. The aim of our present study was to evaluate any possible association of IL 6 and IL 8 gene polymorphisms with HDM-induced NBA in an Indian population.

Methods

IL 6 (− 572G/C, − 597G/A) and IL 8 polymorphisms (− 251A/T, + 781C/T) were analyzed in a HDM-sensitized group (N = 372) and a control group (N = 110). Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR–RFLP) based genotyping was done. Chi-square test and Fisher’s exact tests were applied for statistical analysis.

Results

IL 6 − 597G/A and IL 8 + 781C/T were not associated with HDM-sensitization, while IL 6 − 72G/C and IL 8 − 51A/T showed significant associations in terms of both genotype and allele frequencies. For both the SNPs, minor allele frequencies were significantly higher in the patients compared to the control. Moreover, IL 6 -572G/C and IL 8 -251A/T were found to be strongly linked with HDM sensitization and severity.

Conclusion

This is probably the pioneer study to describe the association of IL 6 and IL 8 polymorphisms with HDM sensitization in any Indian population. The results suggested that IL 6 -572G/C and IL 8 -251A/T may exert a risk of HDM sensitization leading to NBA.

Impact of air pollutants on hospital visits for pediatric asthma in Fuzhou city, southeast China

Rapid social development in China has resulted in severe air pollution and adverse impacts on people's health. Although studies have been conducted on the relationship between exposure to air pollutants and asthma exacerbation, most studies were performed in relatively heavily polluted areas, while little is known about the effect of air pollutants in less polluted areas. We assessed the effects of air pollutants on the risk of asthma-related outpatient and emergency visits of infants and children aged from 0 to 13 years during 2018 to 2020 in Fuzhou city, southeast China. Data of six air pollutants: sulfur dioxide (SO₂), nitrogen dioxides (NO₂), carbon monoxide (CO), daily maximum 8-h average ozone (O₃-8 h), particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀), and particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM_2.5), were obtained from the Environmental Protection Administration of Fuzhou. Data of temperature, humidity, and wind speed were provided by the Meteorological Bureau of Fuzhou. Results revealed that on lag day 6, NO₂, SO₂, and CO were positively associated with the number of outpatient and emergency visits. Among the pollutants, SO₂ had the highest effects on both outpatient visits (RR = 1.672, 95%CI 1.545, 1.809) and emergency visits (RR = 1.495, 95%CI 1.241, 1.800), and its effect on outpatient visits was stronger in children aged 0-4 years than in those aged 5-13 years (RR = 2.331 vs. 1.439). In conclusion, SO₂ contributes substantially to the adverse effects of air pollutants on pediatric respiratory health in Fuzhou. Younger children were more affected by air pollution than their older counterparts.

Korean Red Ginseng Ameliorates Allergic Asthma through Reduction of Lung Inflammation and Oxidation

Six-year-old red ginseng, which is processed from the whole ginseng root via steaming and drying, has been shown to have preventive effects such as antioxidative, anti-inflammatory, and immunomodulatory. In this study, we evaluated the therapeutic effects of Korean red ginseng (KRG) against ovalbumin (OVA)-induced allergic asthma and the underlying mechanisms involved. We injected 20 µg of OVA on days 0 and 14, and mice were challenged with aerosolized OVA via a nebulizer for 1 h on days 21, 22, and 23. KRG was administered at 100 and 300 mg/kg from days 18 to 23. The KRG-treated mice showed significant reductions in their airway hyperresponsiveness, production of reactive oxygen species (ROS), and the number of inflammatory cells compared with the OVA-treated mice. The levels of type 2 cytokines in the bronchoalveolar lavage fluid and expression of OVA-specific immunoglobulin E in the serum, which were elevated in the OVA group, were reduced in the KRG-treated groups. The pro-inflammatory factors, inducible nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells, were downregulated by the KRG administration in a dose-dependent manner. KRG effectively suppressed the inflammatory response by inhibiting ROS production. Our results suggest that KRG may have the potential to alleviate asthma.

First Steps of Asthma Management with a Personalized Ontology Model

Asthma is a chronic respiratory disease characterized by severe inflammation of the bronchial mucosa. Allergic asthma is the most common form of this health issue. Asthma is classified into allergic and non-allergic asthma, and it can be triggered by several factors such as indoor and outdoor allergens, air pollution, weather conditions, tobacco smoke, and food allergens, as well as other factors. Asthma symptoms differ in their frequency and severity since each patient reacts differently to these triggers. Formal knowledge is selected as one of the most promising solutions to deal with these challenges. This paper presents a new personalized approach to manage asthma. An ontology-driven model supported by Semantic Web Rule Language (SWRL) medical rules is proposed to provide personalized care for an asthma patient by identifying the risk factors and the development of possible exacerbations.

Nuclear receptor Nr1d1 alleviates asthma by abating GATA3 gene expression and Th2 cell differentiation

Nuclear receptors are a unique family of transcription factors that play cardinal roles in physiology and plethora of human diseases. The adopted orphan nuclear receptor Nr1d1 is a constitutive transcriptional repressor known to modulate several biological processes. In this study, we found that Nr1d1 plays a decisive role in T helper (Th)-cell polarization and transcriptionally impedes the formation of Th2 cells by directly binding to the promoter region of GATA binding protein 3 (GATA3) gene. Nr1d1 interacts with its cellular companion, the nuclear receptor corepressor and histone deacetylase 3 to form a stable repression complex on the GATA3 promoter. The presence of Nr1d1 also imparts protection against associated inflammatory responses in murine model of asthma and its ligand SR9011 eased disease severity by suppressing Th2 responses. Moreover, Chip-seq profiling uncovered Nr1d1 interactions with other gene subsets that impedes Th2-linked pathways and regulates metabolism, immunity and brain functions, therefore, providing empirical evidence regarding the genetic link between asthma and other comorbid conditions. Thus, Nr1d1 emerges as a molecular switch that could be targeted to subdue asthma.

Sex Plays a Multifaceted Role in Asthma Pathogenesis

Sex is considered an important risk factor for asthma onset and exacerbation. The prevalence of asthma is higher in boys than in girls during childhood, which shows a reverse trend after puberty—it becomes higher in adult females than in adult males. In addition, asthma severity, characterized by the rate of hospitalization and relapse after discharge from the emergency department, is higher in female patients. Basic research indicates that female sex hormones enhance type 2 adaptive immune responses, and male sex hormones negatively regulate type 2 innate immune responses. However, whether hormone replacement therapy in postmenopausal women increases the risk of current asthma and asthma onset remains controversial in clinical settings. Recently, sex has also been shown to influence the pathophysiology of asthma in its relationship with genetic or other environmental factors, which modulate asthmatic immune responses in the airway mucosa. In this narrative review, we highlight the role of sex in the continuity of the asthmatic immune response from sensing allergens to Th2 cell activation based on our own data. In addition, we elucidate the interactive role of sex with genetic or environmental factors in asthma exacerbation in women.

Circular RNA circ_0002594 regulates PDGF-BB-induced proliferation and migration of human airway smooth muscle cells via sponging miR-139-5p/TRIM8 in asthma

BACKGROUND

Asthma is a chronic respiratory disease characterised by the contraction of smooth muscle and remodelling of the airway wall, which is correlated with increased airway smooth muscle mass. Circular RNA (circRNA) circ_0002594 has been reported as a pro-inflammatory factor in allergic asthma. Therefore, this study is designed to explore the role and mechanism of circ_0002594 in human airway smooth muscle cells (HASMC) proliferation and metastasis.

METHODS

Cell proliferative ability, invasion, and migration were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and Wound healing assays. The protein levels of E-cadherin, N-cadherin, and tripartite motif 8 (TRIM8) were detected by western blot assay. The levels of interleukin-6 (IL-6) and IL-13 were detected using Enzyme-linked immunosorbent assays (ELISA). Levels of circ_0002594, microRNA-139-5p (miR-139-5p), TRIM8 were determined by real-time quantitative polymerase chain reaction (RT-qPCR). The binding between miR-139-5p and circ_0002594 or TRIM8 was predicted by Circinteractome or Starbase v2.0, and then verified by a dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays.

RESULTS

Platelet-derived growth factor-BB (PDGF-BB) could trigger HASMC proliferation, metastasis, and inflammation. Circ_0002594 and TRIM8 were elevated in asthma patients and PDGF-BB-treated HASMC, and the miR-139-5p level was decreased. Furthermore, circ_0002594 knockdown could suppress PDGF-BB- stimulated HASMC damage. Mechanism analysis exhibited that circ_0002594 could regulate TRIM8 expression through sponging miR-139-5p.

CONCLUSION

Our findings revealed that circ_0002594 could act as a regulator in the airway remodelling during asthma development partly by the miR-139-5p/TRIM8 axis, hinting at an underlying therapeutic strategy for asthma.

Metabolomic Associations of Asthma in the Hispanic Community Health Study/Study of Latinos

Asthma disproportionally affects Hispanic and/or Latino backgrounds; however, the relation between circulating metabolites and asthma remains unclear. We conducted a cross-sectional study associating 640 individual serum metabolites, as well as twelve metabolite modules, with asthma in 3347 Hispanic/Latino background participants (514 asthmatics, 15.36%) from the Hispanic/Latino Community Health Study/Study of Latinos. Using survey logistic regression, per standard deviation (SD) increase in 1-arachidonoyl-GPA (20:4) was significantly associated with 32% high odds of asthma after accounting for clinical risk factors (p = 6.27 × 10−5), and per SD of the green module, constructed using weighted gene co-expression network, was suggestively associated with 25% high odds of asthma (p = 0.006). In the stratified analyses by sex and Hispanic and/or Latino backgrounds, the effect of 1-arachidonoyl-GPA (20:4) and the green module was predominantly observed in women (OR = 1.24 and 1.37, p < 0.001) and people of Cuban and Puerto-Rican backgrounds (OR = 1.25 and 1.27, p < 0.01). Mutations in Fatty Acid Desaturase 2 (FADS2) affected the levels of 1-arachidonoyl-GPA (20:4), and Mendelian Randomization analyses revealed that high genetically regulated 1-arachidonoyl-GPA (20:4) levels were associated with increased odds of asthma (p < 0.001). The findings reinforce a molecular basis for asthma etiology, and the potential causal effect of 1-arachidonoyl-GPA (20:4) on asthma provides an opportunity for future intervention.

The preliminary investigation of potential response biomarkers to PAHs exposure on childhood asthma

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) is a potential risk factor for asthma prevalence. This study aims to explore whether PAHs exposure is associated with childhood asthma by altering microbial diversity and metabolic profiles.

METHODS

Thirty children with asthma and 30 children as control in Nanjing, China were recruited. Urinary 1-hydroxypyrene (1-OHPyr) level was determined by UPLC-Orbitrap-MS as a PAHs exposure biomarker. Logistic regression was conducted to investigate the association between 1-OHPyr and childhood asthma. Microbial diversity was analyzed by 16S rRNA gene sequencing. Metabolic profiles were obtained by UPLC-Orbitrap-MS methods. Differential microbiota and metabolites were screened and selected as response biomarkers or intermediates. Mediation analysis was conducted to assess the association between PAHs and asthma mediated by intermediates.

RESULTS

Participating children with and without asthma aged 6.43 ± 2.23 years. The urinary 1-OHPyr level ranged from 0.10 to 1.51 μmol/mol (creatinine corrected) in the participants. The urinary 1-OHPyr level was associated with childhood asthma (OR = 7.21, 95% CI: 1.03-50.42 per 1 μmol/mol unit). Microbial diversity was decreased in the group with asthma and there was a significant shift in the abundance of Proteobacteria (at the phylum level), Veillonella and Prevotella (at the genus level). The enrichment pathway analysis showed that differentially expressed metabolites were involved in purine metabolism, amino acid metabolism, and lipid and fatty acid metabolism. The urinary 1-OHPyr level was associated with the abundance of Actinomyces sp. oral clone IO076 and 7-methylguanine that showed a mediation effect on the association between urinary 1-OHPyr levels and childhood asthma by mediation analysis.

CONCLUSIONS

Urinary 1-OHPyr exposure was associated with childhood asthma, microbial diversity, and metabolic profiles. Microbial diversity and metabolic profiles may be intermediates as response biomarkers to PAHs exposure in childhood asthma. Further research is needed to confirm these study results and determine the underlying mechanism.

Integrated metabolic and microbial analysis reveals host-microbial interactions in IgE-mediated childhood asthma

A metabolomics-based approach to address the molecular mechanism of childhood asthma with immunoglobulin E (IgE) or allergen sensitization related to microbiome in the airways remains lacking. Fifty-three children with lowly sensitized non-atopic asthma (n = 15), highly sensitized atopic asthma (n = 13), and healthy controls (n = 25) were enrolled. Blood metabolomic analysis with ¹H-nuclear magnetic resonance (NMR) spectroscopy and airway microbiome composition analysis by bacterial 16S rRNA sequencing were performed. An integrative analysis of their associations with allergen-specific IgE levels for lowly and highly sensitized asthma was also assessed. Four metabolites including tyrosine, isovalerate, glycine, and histidine were uniquely associated with lowly sensitized asthma, whereas one metabolite, acetic acid, was strongly associated with highly sensitized asthma. Metabolites associated with highly sensitized asthma (valine, isobutyric acid, and acetic acid) and lowly sensitized asthma (isovalerate, tyrosine, and histidine) were strongly correlated each other (P < 0.01). Highly sensitized asthma associated metabolites were mainly enriched in pyruvate and acetyl-CoA metabolisms. Metabolites associated with highly sensitized atopic asthma were mostly correlated with microbiota in the airways. Acetic acid, a short-chain fatty acid (SCFA), was negatively correlated with the genus Atopobium (P < 0.01), but positively correlated with the genus Fusobacterium (P < 0.05). In conclusion, metabolomics reveals microbes-related metabolic pathways associated with IgE responses to house dust mite allergens in childhood asthma. A strong correlation of metabolites related to highly sensitized atopic asthma with airway microbiota provides linkages between the host-microbial interactions and asthma endotypes.

Dietary Fibers: Effects, Underlying Mechanisms and Possible Role in Allergic Asthma Management

The prevalence of asthma is increasing, but the cause remains under debate. Research currently focuses on environmental and dietary factors that may impact the gut-lung axis. Dietary fibers are considered to play a crucial role in supporting diversity and activity of the microbiome, as well as immune homeostasis in the gut and lung. This review discusses the current state of knowledge on how dietary fibers and their bacterial fermentation products may affect the pathophysiology of allergic asthma. Moreover, the impact of dietary fibers on early type 2 asthma management, as shown in both pre-clinical and clinical studies, is described. Short-chain fatty acids, fiber metabolites, modulate host immunity and might reduce the risk of allergic asthma development. Underlying mechanisms include G protein-coupled receptor activation and histone deacetylase inhibition. These results are supported by studies in mice, children and adults with allergic asthma. Fibers might also exert direct effects on the immune system via yet to be elucidated mechanisms. However, the effects of specific types of fiber, dosages, duration of treatment, and combination with probiotics, need to be explored. There is an urgent need to further valorize the potential of specific dietary fibers in prevention and treatment of allergic asthma by conducting more large-scale dietary intervention trials.

DNA methylation and gene expression profiles to identify childhood atopic asthma associated genes

Background

Asthma is a chronic inflammatory disorder of the airways involving many different factors. This study aimed to screen for the critical genes using DNA methylation/CpGs and miRNAs involved in childhood atopic asthma.

Methods

DNA methylation and gene expression data (Access Numbers GSE40732 and GSE40576) were downloaded from the Gene Expression Omnibus database. Each set contains 194 peripheral blood mononuclear cell (PBMC) samples of 97 children with atopic asthma and 97 control children. Differentially expressed genes (DEGs) with DNA methylation changes were identified. Pearson correlation analysis was used to select genes with an opposite direction of expression and differences in methylation levels, and then Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed. Protein–protein interaction network and miRNA–target gene regulatory networks were then constructed. Finally, important genes related to asthma were screened.

Results

A total of 130 critical DEGs with DNA methylation changes were screened from children with atopic asthma and compared with control samples from healthy children. GO and KEGG pathway enrichment analysis found that critical genes were primarily related to 24 GO terms and 10 KEGG pathways. In the miRNA–target gene regulatory networks, 9 KEGG pathways were identified. Analysis of the miRNA–target gene network noted an overlapping KEGG signaling pathway, hsa04060: cytokine-cytokine receptor interaction, in which the gene CCL2, directly related to asthma, was involved. This gene is targeted by eight asthma related miRNAs (hsa-miR-206, hsa-miR-19a, hsa-miR-9,hsa-miR-22, hsa-miR-33b, hsa-miR-122, hsa-miR-1, and hsa-miR-23b). The genes IL2RG and CCl4 were also involved in this pathway.

Conclusions

The present study provides a novel insight into the underlying molecular mechanism of childhood atopic asthma.

New Insights on the Role of pentraxin-3 in Allergic Asthma

Pentraxins are soluble pattern recognition receptors that play a major role in regulating innate immune responses. Through their interaction with complement components, Fcγ receptors, and different microbial moieties, Pentraxins cause an amplification of the inflammatory response. Pentraxin-3 is of particular interest since it was identified as a biomarker for several immune-pathological diseases. In allergic asthma, pentraxin-3 is produced by immune and structural cells and is up-regulated by pro-asthmatic cytokines such as TNFα and IL-1β. Strikingly, some recent experimental evidence demonstrated a protective role of pentraxin-3 in chronic airway inflammatory diseases such as allergic asthma. Indeed, reduced pentraxin-3 levels have been associated with neutrophilic inflammation, Th17 immune response, insensitivity to standard therapeutics and a severe form of the disease. In this review, we will summarize the current knowledge of the role of pentraxin-3 in innate immune response and discuss the protective role of pentraxin-3 in allergic asthma.

Switching from omalizumab to mepolizumab: real-life experience from Southern Italy

BACKGROUND

Current availability of several biologic treatments for severe asthma makes it possible to choose the most appropriate for each patient. Sometimes a good percentage of patients with severe asthma may be eligible for biologics that target either the allergic phenotype or the eosinophilic one, but not all respond to that selected as first choice. The aim of our real-life study was to assess whether, for patients with severe eosinophilic allergic asthma, not previously controlled by the anti-IgE omalizumab, the shift to another biologic targeting interleukin-5, such as mepolizumab, may represent a good therapeutic choice.

METHODS

A total of 41 consecutive patients with severe, persistent allergic, eosinophilic asthma, uncontrolled despite treatment with omalizumab, were enrolled in seven certified Clinical Respiratory Units of Southern Italy (Catania, Catanzaro, Foggia, Bari, Palermo, and two University Respiratory Units of Naples) and shifted to mepolizumab without a wash-out period. Data at baseline, after at least 12 months of therapy with omalizumab, and after at least 12 months of treatment with mepolizumab were collected.

RESULTS

After at least 12 months of therapy with mepolizumab, patients experienced a significant decrease in the number of exacerbations/year (5.8 ± 1.8 versus 0.7 ± 0.9, p < 0.0001), an increment of asthma control test score (12 ± 2.7 versus 21.9 ± 2.7, p < 0.0001), an increase in pre-bronchodilator forced expiratory volume in 1 s (1.56 ± 0.45 l versus 1.86 ± 0.52 l, p < 0.0001), and a reduction of blood eosinophils (584 ± 196 cells/µl versus 82 ± 56 cells/µl, p < 0.0001). The percentage of patients who were dependent on corticosteroids significantly decreased from 46% at baseline to 5% during treatment with mepolizumab.

CONCLUSION

Results of our real-life multicentric experience confirms that the shift to mepolizumab could be a good therapeutic strategy in severe eosinophilic allergic asthma not previously controlled by omalizumab. The reviews of this paper are available via the supplemental material section.

Association of asthma with low serum vitamin D and its related musculoskeletal and psychological symptoms in adults: a case-control study

There are complex potential inter-relationships between the chronic inflammation of asthma and poor control, vitamin D deficiency, musculoskeletal pain and anxiety and depression. The aim was to investigate associations between vitamin D and these possible co-morbidities. This case-controlled study involved 75 adults with asthma and 75 controls. Serum 25-hydroxyvitamin D (25(OH)D) was measured, levels of anxiety, depression, musculoskeletal pain, and asthma control were assessed. Participants with asthma had lower 25(OH)D and higher anxiety scores and higher measures of musculoskeletal pain compared to controls. Binary logistic regression showed that asthma was associated with decreased 25(OH)D (Odds ratio (OR) = 0.86), general weakness (OR = 13.29), complaint of musculoskeletal pain (OR = 13.73), and increased intensity of musculoskeletal pain (OR = 0.61) and number of painful sites (OR = 2.58). Asthma was not associated with anxiety or depression. Further studies are required to investigate if vitamin D supplementation can improve asthma symptoms and musculoskeletal pain.

Functional abdominal pain disorders and asthma: two disorders, but similar pathophysiology?

INTRODUCTION

Functional abdominal pain disorders (FAPDs) and asthma are common ailments affecting both children and adults worldwide. Multiple studies have demonstrated an association between these two disorders. However, the exact reason for this observed association is not apparent.

AREAS COVERED

The current review has explored available literature and outlined multiple underlying pathophysiological mechanisms, common to both asthma and FAPDs, as possible reasons for this association.

EXPERT OPINION

Smooth muscle dysfunction, hypersensitivity and hyper-responsiveness, mucosal inflammation, and barrier dysfunction involving gastrointestinal and respiratory tracts are the main underlying pathophysiological mechanisms described for the generation of symptoms in FAPDs and asthma. In addition, alterations in neuroendocrine regulatory functions, immunological dysfunction, and microbial dysbiosis have been described in both disorders. We believe that the pathophysiological processes that were explored in this article would be able to expand the mechanisms of the association. The in-depth knowledge is needed to be converted to therapeutic and preventive strategies to improve the quality of care of children suffering from FAPDs and asthma.

High-Density Lipoprotein (HDL) in Allergy and Skin Diseases: Focus on Immunomodulating Functions

From an evolutionary perspective, lipoproteins are not only lipid transporters, but they also have important functions in many aspects of immunity. High-density lipoprotein (HDL) particles are the most abundant lipoproteins and the most heterogeneous in terms of their composition, structure, and biological functions. Despite strong evidence that HDL potently influences the activity of several immune cells, the role of HDL in allergies and skin diseases is poorly understood. Alterations in HDL-cholesterol levels have been observed in allergic asthma, allergic rhinitis, atopic dermatitis (eczema), psoriasis, urticaria, and angioedema. HDL-associated apolipoprotein (apo) A-I, apoA-IV, and apoC-III, and lyso-phosphatidylcholines potently suppress immune cell effector responses. Interestingly, recent studies provided evidence that allergies and skin diseases significantly affect HDL composition, metabolism, and function, which, in turn, could have a significant impact on disease progression, but may also affect the risk of cardiovascular disease and infections. Interestingly, not only a loss in function, but also, sometimes, a gain in function of certain HDL properties is observed. The objective of this review article is to summarize the newly identified changes in the metabolism, composition, and function of HDL in allergies and skin diseases. We aim to highlight the possible pathophysiological consequences with a focus on HDL-mediated immunomodulatory activities.

Protein S protects against allergic bronchial asthma by modulating Th1/Th2 balance

BACKGROUND

Bronchial asthma is a chronic disease characterized by inflammation, obstruction, and hyperresponsiveness of the airways. There is currently no curative therapy for asthma. Type 2 helper T cell response plays a critical role in the pathogenesis of the disease. Protein S is a glycoprotein endowed with anticoagulant, anti-inflammatory, and anti-apoptotic properties. Whether protein S can suppress bronchial asthma and be useful for its therapy is unknown.

METHODS

To address this question here we compared the development of allergen-associated bronchial asthma between wild type and protein S-overexpressing transgenic mice. Mice were sensitized and challenged with ovalbumin. We also evaluated the circulating levels of total and active protein S in patients with bronchial asthma and healthy controls.

RESULTS

The circulating level of total protein S and of its active form was significantly decreased in patients with bronchial asthma compared to controls. Allergic protein S transgenic mice showed a significant reduction of airway hyperresponsiveness, lung tissue inflammatory cell infiltration, lung levels of Th2 cytokines and IgE compared to their wild-type counterparts. Administration of exogenous human protein S also decreased airway hyperresponsiveness and Th2-mediated lung inflammation in allergic wild-type mice compared with their untreated mouse counterparts. Human protein S significantly shifted the Th1/Th2 balance to Th1 and promoted the secretion of Th1 cytokines (IL-12, tumor necrosis factor-α) from dendritic cells.

CONCLUSIONS

These observations suggest the strong protective activity of protein S against the development of allergic bronchial asthma implicating its potential usefulness for the disease treatment.

The roles of B cell activation factor (BAFF) and a proliferation-inducing ligand (APRIL) in allergic asthma

Allergic asthma, which is the most common type of asthma, is mediated by the IgE response, and B cells are key drivers of allergic inflammation in the lungs. B cell activation factor (BAFF) and proliferation inducing ligand (APRIL) are members of the TNF superfamily. BAFF and APRIL interact with three receptors, namely the B cell activation factor receptor (BAFF-r), B cell maturation antigen (BCMA), and transmembrane activator; calcium modulator; and cyclophilin ligand interactor (TACI). The interaction of BAFF and APRIL with their receptors induces B cell activation, differentiation, and antibody production. BAFF and APRIL are produced by airway epithelial cells during the response to allergens or infectious agents, and have shown to induce local IgE production, thus establishing allergic inflammation in the airways. BAFF can maintain in inflamed airways during infection and can inhibit regulatory T cells (Tregs), thereby promoting allergic inflammation in the airways. This review aims to outline current knowledge about BAFF/APRIL systems in humans as well as in murine models of allergic asthma. The precise role of BAFF and APRIL and their receptors in allergic asthma remains unclear. Therefore, further studies are required to identify and elucidate their roles in enhancing IgE production and activating immune cells that drive the Th2 effector response and initiate allergic inflammation in asthma. Targeting BAFF/APRIL or their cognate receptors may offer a novel therapeutic approach in asthma treatment.

Association between blood aluminum and beta-2 receptor gene methylation with childhood asthma control

Previous studies have shown that environmental exposure to heavy metals has been related to epigenetic changes, such as DNA methylation in receptors involved in pathogenesis of asthma. One of these receptors is beta-2 adrenergic receptor (ADRB2). We conducted this study to examine the association between blood aluminum concentration, blood ADRB2 5' untranslated region (5'-UTR) methylation level, and childhood asthma control level. Our results showed a significant positive association between high blood aluminum concentration (odds ratio, 16, 95% confidence interval (CI) [3.57 to 71.76], p < 0.001) and high blood ADRB2 5'-UTR methylation level (odds ratio, 4.75, 95% CI [1.39 to 16.2], p = 0.013), and risk of uncontrolled asthma. Multivariable logistic regression revealed that higher blood aluminum concentration was independently associated with increased risk of uncontrolled bronchial asthma (odds ratio, 9.10, 95% CI [2.38 to 34.85], p = 0.0013], after controlling for age, sex, and blood ADRB2 5'-UTR methylation level. In addition, blood ADRB2 5'-UTR methylation level significantly correlated with whole blood aluminum concentration in asthmatic children (r = 0.480, p < 0.001). We concluded that increasing blood aluminum concentration is an important independent correlate of risk for uncontrolled bronchial asthma as well as increased blood aluminum concentration caused ADRB2 5'-UTR hyper-methylation with increasing risk of uncontrolled bronchial asthma.

Long noncoding RNA atlas of the inflammation caused by asthma in mice

There is little evidence regarding the roles of long noncoding RNAs (lncRNAs) in inflammation caused by asthma. In this study, we successfully generated an asthma mouse model that was induced by ovalbumin (OVA). The effects of dexamethasone (Dex) treatment on lung tissue were investigated using pathological and biochemical methods, including Diff-Quik staining, enzyme-linked immunosorbent assay (ELISA), hematoxylin-eosin (H&E) staining, and western blotting (WB). The inflammation was effectively relieved with Dex treatment. High-throughput sequencing revealed that a total of 1490 lncRNAs were detected in lung tissue samples. Differential expression analysis revealed that the Dex group had 20 upregulated and 15 downregulated lncRNAs compared with those in the Model group. Moreover, nine differentially expressed and inflammation-related lncRNAs were verified by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the regulation networks of these nine lncRNAs, their potential binding microRNA (miRNAs), and the putative target genes showed that these lncRNAs play important roles in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. We further identified the expression levels of three potential binding miRNAs by qRT-PCR. The results of this study contribute to a better understanding of the functions of lncRNAs in inflammation caused by asthma.

Cordyceps polysaccharide ameliorates airway inflammation in an ovalbumin-induced mouse model of asthma via TGF-β1/Smad signaling pathway

Allergic asthma is a chronic inflammatory disease characterized by airflow obstruction, airway hyperresponsiveness (AHR), airway inflammation, and mucus overproduction. Cordyceps polysaccharide (CPS) is one of the main bioactive compounds of Cordyceps militarisis, a traditional Chinese medicine. In this study, we established a mouse model of asthma using ovalbumin (OVA) challenge and evaluated the potential regulatory effect of CPS (25, 50, and 100 mg/kg) on asthmatic mice. These results showed that the asthmatic mice treated with CPS suppressed the secretion of eotaxin, IL-4, IL-5, IL-13, and IFN-γ in the blood and bronchoalveolar lavage fluid (BALF), and decreased serum IgE levels compared to the vehicle-treated mice. CPS also alleviated inflammatory cell infiltration, goblet cell hyperplasia, and the increases of inflammatory cells in the mouse model of asthma. In addition, OVA-induced AHR was inhibited by CPS treatment. Further analyses of protein expression revealed that CPS inhibited the activation of transforming growth factor β1 (TGF-β1)/Smad pathway in mice with asthma. These findings indicated that CPS might serve as a potential therapeutic agent for the management of allergic asthma.

Multi-city study on air pollution and hospital outpatient visits for asthma in China

BACKGROUND

The proportion of asthma patients with mild to moderate exacerbations is far greater than the number who experience episodes that are severe enough to require emergency room visits or hospital admission. However the routinely collected data from hospitals is absent in the past.

OBJECTIVE

To evaluate associations between short-term exposures to air pollutants and hospital outpatient visits for asthma in China.

METHODS

We obtained data for 143,057 asthma outpatient visits from the largest hospitals in 17 Chinese cities, between Jan 01 2013 and Dec 31 2015. We used daily concentrations of air pollutants measured by the China National Environmental Monitoring Centre. We used a time-stratified case-crossover design, and fitted conditional logistic regression models to determine the associations.

RESULTS

Particulate matter ≤10μm in diameter (PM10) and nitrogen dioxide (NO2) were associated with increased risks of hospital outpatient visits for asthma on the same day, while the effects were delayed for particulate matter ≤2.5μm in diameter (PM2.5) and sulphur dioxide (SO2). For the cumulative effect model at lag05 days, 10 μg/m3 increase in air pollutants concentrations were correlated with hospital outpatient visits for asthma with odds ratios (ORs) and 95% confidence intervals 1.004 (1.000-1.008) for PM2.5, 1.005 (1.002-1.008) for PM10, 1.030 (1.021-1.040) for NO2, and 1.015 (1.008-1.021) for SO2. Almost one in nine (10.9%; 7.7, 13.9%) hospital outpatient visits for asthma were attributable to NO2.

CONCLUSION

Short-term exposures to PM2.5, PM10, NO2 and SO2 were associated with hospital outpatient visits for asthma in China.

Arginine metabolic control of airway inflammation

Inducible nitric oxide synthase (iNOS) and arginase-2 (ARG2) share a common substrate, arginine. Higher expression of iNOS and exhaled NO are linked to airway inflammation in patients. iNOS deletion in animal models suggests that eosinophilic inflammation is regulated by arginine metabolism. Moreover, ARG2 is a regulator of Th2 response, as shown by the development of severe eosinophilic inflammation in ARG2-/- mice. However, potential synergistic roles of iNOS and ARG2 in asthma have not been explored. Here, we hypothesized that arginine metabolic fate via iNOS and ARG2 may govern airway inflammation. In an asthma cohort, ARG2 variant genotypes were associated with arginase activity. ARG2 variants with lower arginase activity, combined with levels of exhaled NO, identified a severe asthma phenotype. Airway inflammation was present in WT, ARG2-/-, iNOS-/-, and ARG2-/-/iNOS-/- mice but was greatest in ARG2-/-. Eosinophilic and neutrophilic infiltration in the ARG2-/- mice was abrogated in ARG2-/-/iNOS-/- animals. Similarly, angiogenic airway remodeling was greatest in ARG2-/- mice. Cytokines driving inflammation and remodeling were highest in lungs of asthmatic ARG2-/- mice and lowest in the iNOS-/-. ARG2 metabolism of arginine suppresses inflammation, while iNOS metabolism promotes airway inflammation, supporting a central role for arginine metabolic control of inflammation.

Albiflorin alleviates ovalbumin (OVA)-induced pulmonary inflammation in asthmatic mice

In the present study, the effects of albiflorin (ALB) on the pulmonary inflammation induced by ovalbumin (OVA) in an asthmatic mouse model were investigated. Airway hyperreactivity (AHR) in asthmatic mice was detected using the acetylcholine stimulation test. Eosinophilia cells in the serum of asthmatic mice were counted. Hematoxylin and eosin (H&E) staining was used to observe pathological changes in lung tissue. Inflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were detected in bronchoalveolar lavage fluid (BALF) and lung tissue using enzyme-linked immunosorbent assay (ELISA). Western blotting was used to detect the mitogen-activated protein kinase/nuclear factor kappa B (MAPK/NF-κB) signaling pathway in the lungs of asthmatic mice. The results from the present study indicated that ALB dramatically suppressed the expression of inflammatory cytokines including IL-1β, IL-6, and TNF-α, and inflammatory cells. In addition, ALB significantly decreased malondialdehyde (MDA) content as well as increased superoxide dismutase (SOD) activity. ALB also alleviated AHR in asthmatic mice and improved pathological changes in the lungs. In addition, ALB inhibited the MAPK/NF-κB signaling pathway in the lungs of the asthmatic mice. Thus, ALB appears to inhibit lung inflammation in asthmatic mice via regulation of the MAPK/NF-κB signaling pathway.

Genetic variations in olfactory receptor gene OR2AG2 in a large multigenerational family with asthma

It is estimated from twin studies that heritable factors account for at-least half of asthma-risk, of which genetic variants identified through population studies explain only a small fraction. Multi-generation large families with high asthma prevalence can serve as a model to identify highly penetrant genetic variants in closely related individuals that are missed by population studies. To achieve this, a four-generation Indian family with asthma was identified and recruited for examination and genetic testing. Twenty subjects representing all generations were selected for whole genome genotyping, of which eight were subjected to exome sequencing. Non-synonymous and deleterious variants, segregating with the affected individuals, were identified by exome sequencing. A prioritized deleterious missense common variant in the olfactory receptor gene OR2AG2 that segregated with a risk haplotype in asthma, was validated in an asthma cohort of different ethnicity. Phenotypic tests were conducted to verify expected deficits in terms of reduced ability to sense odors. Pathway-level relevance to asthma biology was tested in model systems and unrelated human lung samples. Our study suggests that OR2AG2 and other olfactory receptors may contribute to asthma pathophysiology. Genetic studies on large families of interest can lead to efficient discovery.

PM2.5 exposure and cold stress exacerbates asthma in mice by increasing histone acetylation in IL-4 gene promoter in CD4+ T cells

Asthma is a common chronic inflammatory disease which severely reduces the quality of life in patients. Studies have demonstrated that both PM_2.5 and cold stress contribute to the development of asthma. However, the combined effects of these two risking factors are unknown. In this study, we investigated the combined effects of PM_2.5 exposure and cold stress (PMCS) on asthma, as well as the underlying mechanisms by using a murine model. After different exposures, the immune-pathological changes and redox states in groups were evaluated. Besides, the balance of T_H1/T_H2 cells and the acetylation levels of H3K9 and H3K14 in IL-4 gene promotor were detected. Our results showed that, compared with other exposures, PMCS led to an increased inflammation and redox levels in mice. It also significantly increased the percentage of T_H2 T cells, which was correlated with hyperacetylation of H3K9 and H3K14 in IL-4 gene promoter in CD4⁺T cells. Furthermore, a significantly increased P300 and decreased HDAC1 were detected in CD4 + T cells in PMCS group. In conclusion, our findings demonstrated that PMCS exacerbated asthma in mice by increasing H3K9 and H3K14 acetylation in IL-4 gene promoter in CD4 + T cells, and P300 and HDAC1 might contribute to their combined effects.

Maternal history of asthma modifies the risk of childhood persistent asthma associated with maternal age at birth: Results from a large prospective cohort in Canada

BACKGROUND

Asthma is a prevalent disease that affects many Canadians. Persistent asthma can affect quality of life, and has multiple health implications. Maternal age at birth has been associated with many adverse health outcomes in children. Conflicting study results exist regarding maternal age at birth and childhood asthma. The association between maternal age at birth and persistent asthma in children is still unknown.

OBJECTIVE

To investigate the relationship between maternal age at birth and persistent asthma in children at ten years of age.

METHODS

This is a prospective cohort study including all children aged 0-2 years who took part in the first cycle of the National Longitudinal Survey of Children and Youths (NLSCY) and were followed every two years until eight to ten years of age in Cycle 5. An interaction term between maternal age at birth and maternal asthma history was introduced in a multivariate model to examine modification effects of maternal asthma history on the association.

RESULTS

Multivariate logistic regression demonstrated that older maternal age at birth was significantly associated with an increased risk of childhood persistent asthma in mothers with a history of asthma (OR = 1.20, 95% CI: 1.04-1.40, p = .016). No relationship was found in mothers without a history of asthma.

CONCLUSION

Maternal history of asthma has an impact on the association between maternal age at birth and childhood persistent asthma in children by age ten. The finding may help explain the inconsistent results in the literature regarding the risk of asthma associated with maternal age at birth.

Hypersensitivity Reactions to Iodinated Contrast Media: A Multicenter Study of 196 081 Patients

Background Multicenter studies may be required for establishing guidelines for safe usage of iodinated contrast media (ICM). Purpose To identify the prevalence, patterns, risk factors, and preventive measures for ICM-related hypersensitivity reactions (HSRs). Materials and Methods Between March 2017 and October 2017, a total of 196 081 patients who underwent ICM administration were enrolled from seven participating institutions. The occurrence of HSRs and baseline patient information were recorded. χ² and Student t test were performed, and logistic regression analyses were used to identify risk factors that predict occurrence and recurrence of HSR. Results Among 196 081 patients (mean age ± standard deviation, 59.1 years ± 16.0; 105 014 men and 91 067 women) who underwent ICM administration, the overall prevalence of HSRs was 0.73% (1433 of 196 081), and severe reactions occurred in 0.01% (17 of 196 081). Conditional logistic regression for patients with HSR (n = 1433) and a control group (1:1 matched group for age, sex, ICM product, and institution) demonstrated that a patient's previous individual history of an ICM-related HSR (adjusted odds ratio [OR], 198.8; P < .001), hyperthyroidism (adjusted OR, 3.6; P = .04), drug allergy (adjusted OR, 3.5; P < .001), and other allergic diseases (adjusted OR, 6.8; P < .001) and a family history of ICM-related HSRs (adjusted OR, 14.0; P = .01) were predictors of HSR occurrence. Logistic regression analysis showed that use of premedication with antihistamine (OR, 0.5; P = .01) and change in the generic profile of ICM (OR, 0.5; P < .001) were preventive against recurrent HSR. Conclusion Family history as well as previous individual history of hypersensitivity reactions (HSRs) to iodinated contrast media (ICM) were risk factors for HSR occurrence, suggesting a potential genetic predisposition. A change in the culprit ICM and premedication with antihistamine are useful for reducing the recurrence of HSRs. © RSNA, 2019 Online supplemental material is available for this article.

Protective Role of Matrix Metalloproteinase-2 in Allergic Bronchial Asthma

Inflammation, reversible obstruction, and hyperresponsiveness of the airways are characteristic findings of bronchial asthma. Several evidence has demonstrated the involvement of matrix metalloproteinase-2 in allergic airway inflammation. Matrix metalloproteinase-2 may promote aberrant tissue remodeling in late stages of allergic airway inflammation. However, whether matrix metalloproteinase-2 is detrimental or protective in early stages of allergic airway inflammation remains unclear. To evaluate this here we compared the severity of allergic bronchial asthma between mice overexpressing human matrix metalloproteinase-2 and wild type mice. After sensitization and challenge with an allergen, mice overexpressing the human matrix metalloproteinase-2 showed a significant reduction in airway hyperresponsiveness and in the expression of Th2 cytokines and IgE compared to their wild type counterparts. An inhibitor of matrix metalloproteinases abolished this beneficial effect of human matrix metalloproteinase-2 overexpression. Allergen-sensitized and challenged human matrix metalloproteinase-2 transgenic mice had enhanced percentage of M1 macrophages with increased expression of inducible nitric oxide synthase and STAT1 activation in the lungs compared to their wild type counterparts. There was no difference in the percentage of regulatory T cells between mouse groups. The results of this study showed that matrix metalloproteinase-2 is protective in allergic bronchial asthma by promoting polarization of macrophages to M1 phenotype.

Immunological Factors Associated with Adult Asthma in the Aseer Region, Southwestern Saudi Arabia

Background: The prevalence of asthma is on the rise in Saudi Arabia. Data regarding the immunological profile of asthma in adults in the Aseer region, in southwestern Saudi Arabia, have not been well studied. Objectives: Our aim was to study the immunological factors associated with sensitization to asthma among adults in the Aseer region. Methods: A cross-sectional study with a nested case control design in a 1:1 ratio was conducted on a sample of adults attending primary health care centers in the Aseer region. The study used a validated Arabic version of the International study of asthma and allergies in childhood (ISAAC) questionnaire. The presence of wheezing in the past 12 months was used as a proxy for bronchial asthma. Matched age and sex controls were selected. Both groups were tested for complete blood count (CBC), total and differential white blood cell (WBC) count including eosinophils, total immunoglobulin E (IgE) measurement, allergen-specific immunoglobulin E (IgE), and cytokine levels. Results: The present study included 110 cases and 157 age- and sex-matched controls. Rye wheat was found to be a significant outdoor sensitizing agent ((odds ratio) OR = 5.23, 95% CI: 1.06–25.69). Indoors, house dust mites Dermatophagoides petronyssinus (OR = 2.04, 95% CI: 1.04–3.99) and Dermatophagoides farinae (OR = 2.50, 95% CI: 1.09–5.75) were significant. Higher total IgE (OR = 1.84, 95% CI: 1.10–3.06) and eosinophil levels (OR = 2.85, 95% CI: 1.14–7.15) were significantly associated with adult bronchial asthma in Aseer. On the other hand, the role of cytokines was not significant. Conclusions: In the present study, certain environmental agents were found to be important with regards to sensitization to bronchial asthma in adults. Knowledge about these sensitization agents should be disseminated to health providers and treating physicians in order to enhance preventive environmental control measures and asthma management. Asthma-treating physicians in the region should be alerted to the use of targeted biological therapies in selected asthmatics with difficult-to-control courses.

The impact of therapy on the risk of asthma in type 2 diabetes

BACKGROUND AND OBJECTIVES

There are limited data about the risk of asthma in people with diabetes. We examined the incidence of asthma in subjects with type 2 diabetes (T2DM) compared to controls, and the association with metformin, sulphonylureas and insulin therapy.

MATERIALS AND METHODS

We conducted a retrospective cohort study using a representative UK primary care database (N = 894 646 adults). We used 1:1 propensity score matching (age, gender, socio-economic deprivation, body mass index and smoking status) to match 29 217 pairs of T2DM cases and controls. We used Cox proportional hazard regression to compare the incidence of asthma in both groups over 8 years of follow-up. In those with T2DM, we used Cox proportional hazard regression to assess for any impact of antidiabetic medications on asthma incidence.

RESULTS

Individuals with T2DM were less likely to develop asthma than matched controls (hazard ratio [HR] 0.85, 95% CI 0.77-0.93). Insulin increased the risk of incident asthma (HR 1.25, 95% CI 1.01-1.56), whilst metformin and sulphonylureas were associated with reduced risk (HR 0.80, 95% CI 0.69-0.93 and HR 0.76, 95% CI 0.60-0.97, respectively). There was no association with diabetes duration, complications or glycaemic control.

CONCLUSIONS

T2DM may have a protective effect against asthma development. Insulin use was associated with an increased risk of asthma, while metformin and sulphonylureas reduced the risk in those with T2DM.

Regulation of IL-17A and implications for TGF-β1 comodulation of airway smooth muscle remodeling in severe asthma

Severe asthma develops as a result of heightened, persistent symptoms that generally coincide with pronounced neutrophilic airway inflammation. In individuals with severe asthma, symptoms are poorly controlled by high-dose inhaled glucocorticoids and often lead to elevated morbidity and mortality rates that underscore the necessity for novel drug target identification that overcomes limitations in disease management. Many incidences of severe asthma are mechanistically associated with T helper 17 (T_H17) cell-derived cytokines and immune factors that mediate neutrophilic influx to the airways. T_H17-secreted interleukin-17A (IL-17A) is an independent risk factor for severe asthma that impacts airway smooth muscle (ASM) remodeling. T_H17-derived cytokines and diverse immune mediators further interact with structural cells of the airway to induce pathophysiological processes that impact ASM functionality. Transforming growth factor-β1 (TGF-β1) is a pivotal mediator involved in airway remodeling that correlates with enhanced T_H17 activity in individuals with severe asthma and is essential to T_H17 differentiation and IL-17A production. IL-17A can also reciprocally enhance activation of TGF-β1 signaling pathways, whereas combined T_H1/T_H17 or T_H2/T_H17 immune responses may additively impact asthma severity. This review seeks to provide a comprehensive summary of cytokine-driven T cell fate determination and T_H17-mediated airway inflammation. It will further review the evidence demonstrating the extent to which IL-17A interacts with various immune factors, specifically TGF-β1, to contribute to ASM remodeling and altered function in T_H17-driven endotypes of severe asthma.

Activation of TLR Signaling in Sensitization-Recruited Inflammatory Monocytes Attenuates OVA-Induced Allergic Asthma

The activation of Toll-like receptor (TLR) signaling is widely reported to be involved in preventing the development of allergic asthma. However, the mechanism of the protective function of TLR signaling remains limited. Here, we studied the mouse model of ovalbumin (OVA)-induced allergic asthma and found that deficiency of TLR signaling or activating TLR signaling with agonist would aggravate or attenuate OVA-induced allergic asthma, respectively, and TLR signaling-mediated protective effect mainly affected the sensitization phase. After OVA/alum sensitization, neutrophils and inflammatory monocytes were recruited into peritoneal cavity and up-regulated TLRs expression. However, adoptive transfer of inflammatory monocytes but not peritoneal macrophages or neutrophils induced allergic symptoms in recipient mice after OVA challenge even without OVA/alum sensitization, and treating the inflammatory monocytes with TLR agonist in vitro before transfer could abolish this effect, indicating that recruited inflammatory monocytes played a determinant role in OVA-induced allergic asthma, and activation of TLR signaling in them could attenuate allergic symptoms. Finally, we found that activation of TLR signaling could increase the expression of T-helper (Th) 1-associated cytokines in inflammatory monocytes. Our results suggest that activation of TLR signaling in sensitization-recruited inflammatory monocytes attenuates OVA-induced allergic asthma by promoting the expression of Th1-associated cytokines.

GAS5 promotes airway smooth muscle cell proliferation in asthma via controlling miR-10a/BDNF signaling pathway

AIMS

To explore the role of long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) in the cell proliferation of airway smooth muscle cells (ASMCs) in asthma.

MATERIALS AND METHODS

An asthma rat model was established by ovalbumin sensitization and challenge. The expression of GAS5, miR-10a and BDNF mRNA and protein was determined with qRT-PCR and western blot, separately. The targeting relationship between GAS5 and miR-10a was examined with RNA immunoprecipitation and RNA pull-down assay; the interaction between miR-10a and BDNF was evaluated by luciferase reporter assay. Cell Proliferation Assay (MTS) was used for ASMC proliferation detection. Knock-down of GAS5 was performed in asthmatic rats to determine the effects of GAS5 in vivo.

KEY FINDINGS

Compared with control group, the inspiratory resistance and expiratory resistance were increased in asthma group; and the expression of GAS5, miR-10a and BDNF was higher, lower and higher, respectively. The expression of GAS5 and miR-10a was elevated and repressed, respectively, by platelet-derived growth factor-BB (PDGF-BB). GAS5 functioned as a bait of miR-10a. GAS5 regulates BDNF expression through miR-10a. PDGF-BB promotes the cell proliferation of ASMCs through miR-10a/BDNF. Knock-down of GAS5 significantly decreased airway hyperresponsiveness in asthmatic rats.

SIGNIFICANCE

The lncRNA GAS5/miR-10a/BDNF regulatory axis played an important role in promoting ASMCs proliferation, thus contributing to asthma.

Nonallergic Asthma and Its Severity: Biomarkers for Its Discrimination in Peripheral Samples

Asthma is a complex and heterogeneous respiratory disorder characterized by chronic airway inflammation. It has generally been associated with allergic mechanisms related to type 2 airway inflammation. Nevertheless, between 10 and 33% of asthmatic individuals have nonallergic asthma (NA). Several targeted treatments are in clinical development for patients with Th2 immune response, but few biomarkers are been defined for low or non-Th2-mediated inflammation asthma. We have recently defined by gene expression a set of genes as potential biomarkers of NA, mainly associated with disease severity: IL10, MSR1, PHLDA1, SERPINB2, CHI3L1, IL8, and PI3. Here, we analyzed their protein expression and specificity using sera and isolated peripheral blood mononuclear cells (PBMCs). First, protein quantification was carried out using ELISA (in sera) or Western blot (proteins extracted from PBMCs by Trizol procedure), depending on the biomarker in 30 healthy controls (C) subjects and 30 NA patients. A receiver operating characteristic curve analysis was performed by using the R program to study the specificity and sensitivity of the candidate biomarkers at a gene- and protein expression level. Four kinds of comparisons were performed: total NA group vs C group, severe NA patients vs C, moderate-mild NA patients vs C, and severe NA patients vs moderate-mild NA patients. We found that all the single genes showed good sensitivity vs specificity for some phenotypic discrimination, with CHI3L1 and PI3 exhibiting the best results for C vs NA: CHI3L1 area under the curve (AUC) (CI 95%): 0.95 (0.84-1.00) and PI3 AUC: 0.99 (0.98-1.00); C vs severe NA: PI3 AUC: 1 (0.99-1.00); and C vs moderate-mild NA: CHI3L1 AUC: 1 (0.99-1.00) and PI3 AUC: 0.99 (0.96-1.00). However, the results for discriminating asthma disease and severity with protein expression were better when two or three biomarkers were combined. In conclusion, individual genes and combinations of proteins have been evaluated as reliable biomarkers for classifying NA subjects and their severity. These new panels could be good diagnostic tests.

Dental follicle mesenchymal stem cells down-regulate Th2-mediated immune response in asthmatic patients mononuclear cells

BACKGROUND

Asthma is a chronic inflammatory disease in which inflammatory responses have the polarisation of CD4⁺ T cells to Th2 cells. Dental follicle mesenchymal stem cells (DFSCs) have strong anti-inflammatory properties comparable to other mesenchymal stem cells.

OBJECTIVE

We investigated the immunomodulatory effects of DFSCs on CD4⁺ T helper cell responses of asthmatic patients and compared the results with those obtained with asthmatic subjects on immunotherapy and with healthy individuals.

METHOD

Peripheral blood mononuclear cells (PBMC) were isolated from immunotherapy naïve asthmatics, asthmatics on subcutaneous Der p1 immunotherapy and from healthy individuals. PBMC were pre-conditioned with anti-CD3/anti-CD28 mAbs, Der p1 or IFN-γ in the presence and absence of DFSCs and analysed for T cell viability and proliferation, CD4⁺ CD25⁺ FOXP3⁺ regulatory T cell frequencies, cytokine expression, and GATA3, T bet and FoxP3 expressions. Neutralisation of TGF-β and blockade of IDO and PGE2 pathways were performed to determine suppressive signalling pathways of DFSCs.

RESULTS

Dental follicle mesenchymal stem cells suppressed proliferative responses of CD4⁺ T lymphocytes and increased the frequency of Treg cells. DFSCs decreased effector and effector memory CD4⁺ T cell phenotypes in favour of naïve T cell markers. DFSCs decreased IL-4 and GATA3 expression and increased IFN-γ, T-bet and IL-10 expression in asthmatics. Costimulatory molecules were suppressed in monocytes with DFSCs in the cocultures. DFSCs down-regulated inflammatory responses via IDO and TGF-β pathways in asthmatic patients.

CONCLUSION

Dental follicle mesenchymal stem cells suppressed allergen-induced Th2-cell polarisation in favour of Th1 responses and attenuated antigen-presenting cell co-stimulatory activities. These studies suggest that DFSC-based cell therapy may provide pro-tolerogenic immunomodulation relevant to allergic diseases such as asthma.

Asthma and poly(ADP-ribose) polymerase inhibition: a new therapeutic approach

Asthma is a chronic lung disease affecting people of all ages worldwide, and it frequently begins in childhood. Because of its chronic nature, it is characterized by pathological manifestations, including airway inflammation, remodeling, and goblet cell hyperplasia. Current therapies for asthma, including corticosteroids and beta-2 adrenergic agonists, are directed toward relieving the symptoms of the asthmatic response, with poor effectiveness against the underlying causes of the disease. Asthma initiation and progression depends on the T helper (Th) 2 type immune response carried out by a complex interplay of cytokines, such as interleukin (IL) 4, IL5, and IL13, and the signal transducer and activator of transcription 6. Much of the data resulting from different laboratories support the role of poly(ADP-ribose) polymerase (PARP) 1 and PARP14 activation in asthma. Indeed, PARP enzymes play key roles in the regulation and progression of the inflammatory asthma process because they affect the expression of genes and chemokines involved in the immune response. Consistently, PARP inhibition achievable either upon genetic ablation or by using pharmacological agents has shown a range of therapeutic effects against the disease. Indeed, in the last two decades, several preclinical studies highlighted the protective effects of PARP inhibition in various animal models of asthma. PARP inhibitors showed the ability to reduce the overall lung inflammation acting with a specific effect on immune cell recruitment and through the modulation of asthma-associated cytokines production. PARP inhibition has been shown to affect the Th1–Th2 balance and, at least in some aspects, the airway remodeling. In this review, we summarize and discuss the steps that led PARP inhibition to become a possible future therapeutic strategy against allergic asthma.