miR-34c-5p inhibited fibroblast proliferation, differentiation and epithelial-mesenchymal transition in benign airway stenosis via MDMX/p53 pathway.

Benign airway stenosis (BAS) means airway stenosis or obstruction that results from a variety of non-malignant factors, including tuberculosis, trauma, benign tumors, etc. In consideration of the currently limited research on microRNAs in BAS, this study aimed to explore the role and mechanism of miR-34c-5p in BAS. The expression of miR-34c-5p in BAS granulation tissues showed a significant down-regulation compared with the normal control group. Moreover, miR-34c-5p mimics suppressed the proliferation and differentiation of human bronchial fibroblasts (HBFs) and the epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBE). Conversely, miR-34c-5p inhibitors aggravated those effects. A dual-luciferase reporter assay confirmed that miR-34c-5p can target MDMX rather than Notch1. The over-expression of MDMX can reverse the inhibiting effect of miR-34c-5p on HBFs proliferation, differentiation and EMT. Furthermore, the expressions of tumor protein (p53) and PTEN were down-regulated following the over-expression of MDMX. In addition, the expressions of PI3K and AKT showed an up-regulation. In conclusion, miR-34c-5p was down-regulated in BAS and may inhibit fibroblast proliferation differentiation and EMT in BAS via the MDMX/p53 signaling axis. These findings expand the understanding of the role of miR-34c-5p and will help develop new treatment strategies for BAS.

Robin sequence without cleft palate: Genetic diagnoses and management implications.

Robin sequence (RS), the triad of micrognathia, glossoptosis, and airway obstruction, is a major cause of respiratory distress and feeding difficulties in neonates. Robin sequence can be associated with other medical or developmental comorbidities in ~50% of cases ("syndromic" RS). As well, RS is variably associated with cleft palate (CP). Previous studies have not investigated differences in clinical characteristics of children with RS based on presence or absence of CP. We retrospectively reviewed 175 children with RS and compared genetic diagnoses, medical and developmental comorbidities, severity of airway obstruction, and feeding outcomes between those with and without CP. Strikingly, 45 of 45 (100%) children with RS without CP were classified as syndromic due to presence of comorbidities unrelated to RS, while 83 of 130 (64%) children with RS with CP were classified as syndromic. Among 128 children with syndromic RS, there were no differences in severity of airway obstruction, surgical intervention rate or type, or feeding outcome at 12 months based on CP status. Our findings support the conclusion that the pathogenesis of RS without CP is distinct from RS with CP and more likely to cause additional medical or developmental problems. Alternatively, children with RS without CP and without additional anomalies present may be under recognized.

Genetic Evidence on the Association of Interleukin (IL)-1-Mediated Chronic Inflammation with Airflow Obstruction: A Mendelian Randomization Study.

Preclinical studies suggest interleukin (IL)-1α/ß is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, recent trials of anti-IL-1 therapies showed limited benefit for COPD. To clarify, we primarily examined total and direct effects of IL-1 and its receptors/coreceptors/receptor antagonists (IL-1/IL-1Rs) on airflow obstruction (AO) using Mendelian randomization (MR), and secondarily explored reverse causation using bidirectional MR. We selected independent cis protein quantitative trait loci (cis-pQTLs) as genetic instruments for IL-1/IL-1Rs from two proteomic genome-wide association studies (n = 11,594) of European ancestry (mean age ∼47 years). We applied those cis-pQTLs to the International COPD Genetics Consortium (n = 15,256 cases, 47,936 controls) of ∼81.9% European descent (∼57 years). No IL-1/IL-1Rs were significantly associated with AO after correction for multiple testing. However, a higher genetically predicted IL-1 receptor antagonist (IL-1Ra) was nominally associated with a 20% reduction in AO risk using univariable MR, with a larger direct effect (∼31%, i.e. not via IL-1α/ß) using multivariable MR. Furthermore, higher total IL-18 binding protein (IL-18BP) was nominally associated with lower AO. Nominal total effects were also noted for higher IL-1α with lower AO and higher IL-1R1 with higher AO. Higher IL-1Ra and IL-18BP might have a role in preventing AO, but need to be contextualized.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.1955848 .

The Airway Epithelium-A Central Player in Asthma Pathogenesis.

Asthma is a chronic inflammatory airway disease characterized by variable airflow obstruction in response to a wide range of exogenous stimuli. The airway epithelium is the first line of defense and plays an important role in initiating host defense and controlling immune responses. Indeed, increasing evidence indicates a range of abnormalities in various aspects of epithelial barrier function in asthma. A central part of this impairment is a disruption of the airway epithelial layer, allowing inhaled substances to pass more easily into the submucosa where they may interact with immune cells. Furthermore, many of the identified susceptibility genes for asthma are expressed in the airway epithelium. This review focuses on the biology of the airway epithelium in health and its pathobiology in asthma. We will specifically discuss external triggers such as allergens, viruses and alarmins and the effect of type 2 inflammatory responses on airway epithelial function in asthma. We will also discuss epigenetic mechanisms responding to external stimuli on the level of transcriptional and posttranscriptional regulation of gene expression, as well the airway epithelium as a potential treatment target in asthma.

SOCS3 overexpression in T cells ameliorates chronic airway obstruction in a murine heterotopic tracheal transplantation model.

PURPOSE: Suppressor of cytokine signaling-3 (SOCS3) is a negative feedback inhibitor of cytokine signaling with T-cell-mediated immunosuppressive effects on obliterative bronchiolitis (OB). In this study, we aimed to investigate the impact of T-cell-specific overexpression of SOCS3 using a murine heterotopic tracheal transplantation (HTT) model. METHODS: Tracheal allografts from BALB/c mice were subcutaneously transplanted into wild-type C57BL/6J (B6; WT) mice and SOCS3 transgenic B6 (SOCS3TG) mice. Tracheal allografts were analyzed by immunohistochemistry and quantitative polymerase chain reaction assays at days 7 and 21. RESULTS: At day 21, allografts in SOCS3TG mice showed significant amelioration of airway obstruction and epithelial loss compared with allografts in WT mice. The intragraft expression of IFN-γ and CXCL10 was suppressed, while that of IL-4 was enhanced in SOCS3TG mice at day 7. The T-bet levels were lower in SOCS3TG allografts than in WT allografts at day 7. CONCLUSION: We revealed that the overexpression of SOCS3 in T cells effectively ameliorates OB development in a murine HTT model by inhibiting the Th1 phenotype in the early phase. Our results suggest that the regulation of the T-cell response, through the modulation of SOCS expression, has potential as a new therapeutic strategy for chronic lung allograft dysfunction.

Novel compound heterozygous DPH1 mutations in a patient with the unique clinical features of airway obstruction and external genital abnormalities.

The diphthamide biosynthesis 1 (DPH1) gene encodes one of the essential components of the enzyme catalyzing the first step of diphthamide formation on eukaryotic elongation factor 2 (EEF2). Diphthamide is the posttranslationally modified histidine residue on EEF2 that promotes protein chain elongation in the ribosome. DPH1 defects result in a failure of protein synthesis involving EEF2, leading to growth defects, embryonic lethality, and cell death. In humans, DPH1 mutations cause developmental delay with a short stature, dysmorphic features, and sparse hair, and are inherited in an autosomal recessive manner (MIM#616901). To date, only two homozygous missense mutations in DPH1 (c.17T>A, p.Met6Lys and c.701T>C, p.Leu234Pro) have been reported. We used WES to identify novel compound heterozygous mutations in DPH1 (c.289delG, p.Glu97Lysfs*8 and c.491T>C, p.Leu164Pro) in a patient from a nonconsanguineous family presenting with intellectual disability, a short stature, craniofacial abnormalities, and external genital abnormalities. The clinical phenotype of all patients with DPH1 mutations, including the current patient, revealed core features, although the external genital anomaly was newly recognized in our case.

Integrative pathway genomics of lung function and airflow obstruction.

Chronic respiratory disorders are important contributors to the global burden of disease. Genome-wide association studies (GWASs) of lung function measures have identified several trait-associated loci, but explain only a modest portion of the phenotypic variability. We postulated that integrating pathway-based methods with GWASs of pulmonary function and airflow obstruction would identify a broader repertoire of genes and processes influencing these traits. We performed two independent GWASs of lung function and applied gene set enrichment analysis to one of the studies and validated the results using the second GWAS. We identified 131 significantly enriched gene sets associated with lung function and clustered them into larger biological modules involved in diverse processes including development, immunity, cell signaling, proliferation and arachidonic acid. We found that enrichment of gene sets was not driven by GWAS-significant variants or loci, but instead by those with less stringent association P-values. Next, we applied pathway enrichment analysis to a meta-analyzed GWAS of airflow obstruction. We identified several biologic modules that functionally overlapped with those associated with pulmonary function. However, differences were also noted, including enrichment of extracellular matrix (ECM) processes specifically in the airflow obstruction study. Network analysis of the ECM module implicated a candidate gene, matrix metalloproteinase 10 (MMP10), as a putative disease target. We used a knockout mouse model to functionally validate MMP10's role in influencing lung's susceptibility to cigarette smoke-induced emphysema. By integrating pathway analysis with population-based genomics, we unraveled biologic processes underlying pulmonary function traits and identified a candidate gene for obstructive lung disease.

PAI-1 gain-of-function genotype, factors increasing PAI-1 levels, and airway obstruction: The GALA II Cohort.

BACKGROUND: PAI-1 gain-of-function variants promote airway fibrosis and are associated with asthma and with worse lung function in subjects with asthma. OBJECTIVE: We sought to determine whether the association of a gain-of-function polymorphism in plasminogen activator inhibitor-1 (PAI-1) with airway obstruction is modified by asthma status, and whether any genotype effect persists after accounting for common exposures that increase PAI-1 level. METHODS: We studied 2070 Latino children (8-21y) with genotypic and pulmonary function data from the GALA II cohort. We estimated the relationship of the PAI-1 risk allele with FEV1/FVC by multivariate linear regression, stratified by asthma status. We examined the association of the polymorphism with asthma and airway obstruction within asthmatics via multivariate logistic regression. We replicated associations in the SAPPHIRE cohort of African Americans (n=1056). Secondary analysis included the effect of the at-risk polymorphism on postbronchodilator lung function. RESULTS: There was an interaction between asthma status and the PAI-1 polymorphism on FEV1 /FVC (P=.03). The gain-of-function variants, genotypes (AA/AG), were associated with lower FEV1 /FVC in subjects with asthma (ß=-1.25, CI: -2.14,-0.35, P=.006), but not in controls. Subjects with asthma and the AA/AG genotypes had a 5% decrease in FEV1 /FVC (P<.001). In asthmatics, the risk genotype (AA/AG) was associated with a 39% increase in risk of clinically relevant airway obstruction (OR=1.39, CI: 1.01, 1.92, P=.04). These associations persisted after exclusion of factors that increase PAI-1 including tobacco exposure and obesity. CONCLUSIONS AND CLINICAL RELEVANCE: The decrease in the FEV1 /FVC ratio associated with the risk genotype was modified by asthma status. The genotype increased the odds of airway obstruction by 75% within asthmatics only. As exposures known to increase PAI-1 levels did not mitigate this association, PAI-1 may contribute to airway obstruction in the context of chronic asthmatic airway inflammation.

A genome-wide association study for equine recurrent airway obstruction in European Warmblood horses reveals a suggestive new quantitative trait locus on chromosome 13.

Recurrent airway obstruction (RAO), also known as heaves, is an asthma-like respiratory disease. Its development is strongly influenced by environmental risk factors such as sensitization and exposure to moldy hay, straw bedding and stabling indoors. A hereditary component has been documented in previous studies; however, so far no causative genetic variant that influences the risk of developing RAO has been identified. In this study, we revised an existing dataset and selected 384 horses for genotyping on the Affymetrix high-density equine SNP array. We performed an allelic case-control genome-wide association study, which revealed a suggestively significant association on equine chromosome 13 at 32 843 309 bp. This SNP is located in the protein-coding gene TXNDC11, which is possibly involved in the folding process of the multiprotein complexes DUOX1 and DUOX2. In humans, these proteins are known to take part in regulating the production of H2 O2 in the respiratory tract epithelium as well as in MUC5AC mucin expression. Therefore, TXNDC11 may be considered a functional candidate gene, and further research is needed to explore its potential role in RAO-affected horses.

Exome-wide analysis of rare coding variation identifies novel associations with COPD and airflow limitation in MOCS3, IFIT3 and SERPINA12.

BACKGROUND: Several regions of the genome have shown to be associated with COPD in genome-wide association studies of common variants. OBJECTIVE: To determine rare and potentially functional single nucleotide polymorphisms (SNPs) associated with the risk of COPD and severity of airflow limitation. METHODS: 3226 current or former smokers of European ancestry with lung function measures indicative of Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 COPD or worse were genotyped using an exome array. An analysis of risk of COPD was carried out using ever smoking controls (n=4784). Associations with %predicted FEV1 were tested in cases. We followed-up signals of interest (p<10(-5)) in independent samples from a subset of the UK Biobank population and also undertook a more powerful discovery study by meta-analysing the exome array data and UK Biobank data for variants represented on both arrays. RESULTS: Among the associated variants were two in regions previously unreported for COPD; a low frequency non-synonymous SNP in MOCS3 (rs7269297, pdiscovery=3.08×10(-6), preplication=0.019) and a rare SNP in IFIT3, which emerged in the meta-analysis (rs140549288, pmeta=8.56×10(-6)). In the meta-analysis of % predicted FEV1 in cases, the strongest association was shown for a splice variant in a previously unreported region, SERPINA12 (rs140198372, pmeta=5.72×10(-6)). We also confirmed previously reported associations with COPD risk at MMP12, HHIP, GPR126 and CHRNA5. No associations in novel regions reached a stringent exome-wide significance threshold (p<3.7×10(-7)). CONCLUSIONS: This study identified several associations with the risk of COPD and severity of airflow limitation, including novel regions MOCS3, IFIT3 and SERPINA12, which warrant further study.

Analysis of genomic copy number variation in equine recurrent airway obstruction (heaves).

We explored the involvement of genomic copy number variants (CNVs) in susceptibility to recurrent airway obstruction (RAO), or heaves-an asthmalike inflammatory disease in horses. Analysis of 16 RAO-susceptible (cases) and six RAO-resistant (control) horses on a custom-made whole-genome 400K equine tiling array identified 245 CNV regions (CNVRs), 197 previously known and 48 new, distributed on all horse autosomes and the X chromosome. Among the new CNVRs, 30 were exclusively found in RAO cases and were further analyzed by quantitative PCR, including additional cases and controls. Suggestive association (P = 0.03; corrected P = 0.06) was found between RAO and a loss on chromosome 5 involving NME7, a gene necessary for ciliary functions in lungs and involved in primary ciliary dyskinesia in humans. The CNVR could be a potential marker for RAO susceptibility but needs further study in additional RAO cohorts. Other CNVRs were not associated with RAO, although several involved genes of interest, such as SPI2/SERPINA1 from the serpin gene family, which are associated with chronic obstructive pulmonary disease and asthma in humans. The SPI2/SERPINA1 CNVR showed striking variation among horses, but it was not significantly different between RAO cases and controls. The findings provide baseline information on the relationship between CNVs and RAO susceptibility. Discovery of new CNVs and the use of a larger population of RAO-affected and control horses are needed to shed more light on their significance in modulating this complex and heterogeneous disease.

Lack of neutrophil elastase reduces inflammation, mucus hypersecretion, and emphysema, but not mucus obstruction, in mice with cystic fibrosis-like lung disease.

RATIONALE: Recent evidence from clinical studies suggests that neutrophil elastase (NE) released in neutrophilic airway inflammation is a key risk factor for the onset and progression of lung disease in young children with cystic fibrosis (CF). However, the role of NE in the complex in vivo pathogenesis of CF lung disease remains poorly understood. OBJECTIVES: To elucidate the role of NE in the development of key features of CF lung disease including airway inflammation, mucus hypersecretion, goblet cell metaplasia, bacterial infection, and structural lung damage in vivo. METHODS: We used the Scnn1b-Tg mouse as a model of CF lung disease and determined effects of genetic deletion of NE (NE(-/-)) on the pulmonary phenotype. Furthermore, we used novel Foerster resonance energy transfer (FRET)-based NE reporter assays to assess NE activity in bronchoalveolar lavage from Scnn1b-Tg mice and sputum from patients with CF. MEASUREMENTS AND MAIN RESULTS: Lack of NE significantly reduced airway neutrophilia, elevated mucin expression, goblet cell metaplasia, and distal airspace enlargement, but had no effect on airway mucus plugging, bacterial infection, or pulmonary mortality in Scnn1b-Tg mice. By using FRET reporters, we show that NE activity was elevated on the surface of airway neutrophils from Scnn1b-Tg mice and patients with CF. CONCLUSIONS: Our results suggest that NE plays an important role in the in vivo pathogenesis and may serve as a therapeutic target for inflammation, mucus hypersecretion, and structural lung damage and indicate that additional rehydration strategies may be required for effective treatment of airway mucus obstruction in CF.

[THE VALUE OF RECURRENT BRONCHIAL OBSTRUCTION ASSOCIATED WITH RESPIRATORY INFECTIONS IN INFANTS].

It is shown that recurrent bronchial obstruction with nonallergic genesis is a significant problem for young children. Further researches of this disease are needed in order to develop differentiated therapies.

Effect of antigen sensitization and challenge on oscillatory mechanics of the lung and pulmonary inflammation in obese carboxypeptidase E-deficient mice.

Atopic, obese asthmatics exhibit airway obstruction with variable degrees of eosinophilic airway inflammation. We previously reported that mice obese as a result of a genetic deficiency in either leptin (ob/ob mice) or the long isoform of the leptin receptor (db/db mice) exhibit enhanced airway obstruction in the presence of decreased numbers of bronchoalveolar lavage fluid (BALF) eosinophils compared with lean, wild-type mice following antigen (ovalbumin; OVA) sensitization and challenge. To determine whether the genetic modality of obesity induction influences the development of OVA-induced airway obstruction and OVA-induced pulmonary inflammation, we examined indices of these sequelae in mice obese as a result of a genetic deficiency in carboxypeptidase E, an enzyme that processes prohormones and proneuropeptides involved in satiety and energy expenditure (Cpe(fat) mice). Accordingly, Cpe(fat) and lean, wild-type (C57BL/6) mice were sensitized to OVA and then challenged with either aerosolized PBS or OVA. Compared with genotype-matched, OVA-sensitized and PBS-challenged mice, OVA sensitization and challenge elicited airway obstruction and increased BALF eosinophils, macrophages, neutrophils, IL-4, IL-13, IL-18, and chemerin. However, OVA challenge enhanced airway obstruction and pulmonary inflammation in Cpe(fat) compared with wild-type mice. These results demonstrate that OVA sensitization and challenge enhance airway obstruction in obese mice regardless of the genetic basis of obesity, whereas the degree of OVA-induced pulmonary inflammation is dependent on the genetic modality of obesity induction. These results have important implications for animal models of asthma, as modeling the pulmonary phenotypes for subpopulations of atopic, obese asthmatics critically depends on selecting the appropriate mouse model.

Introduction to asthma and phenotyping.

Asthma is an inflammatory disorder characterized by airway obstruction, airway hyperresponsiveness, and airway inflammation, all of which are variable among patients and variable in time within any specific patient. Understanding the mechanism that underlies this observed variability, and using that understanding to advance the science of asthma and the care of asthmatic patients, is an essential purpose of developing phenotypes. Clinical phenotypes have been used for decades, but overlap each other, and do not map cleanly to either pathophysiologic mechanism or with therapeutic response. Molecular phenotyping, although as yet only partially developed, offers the promise of dissecting the mechanistic underpinnings of the variability of asthma and of providing predictive therapeutics for the benefit of patients with this common and troubling disease.

Introduction to genetics and genomics in asthma: genetics of asthma.

While asthma is a heterogeneous disease, a strong genetic basis has been firmly established. Rather than being a single disease entity, asthma consists of related, overlapping syndromes [Barnes (Proc Am Thor Soc 8:143-148, 2011)] including three general domains: variable airway obstruction, airway hyper-responsiveness, and airway inflammation with a considerable proportion, but not all, of asthma being IgE-mediated further adding to its heterogeneity. This chapter reviews the approaches to the elucidation of genetics of asthma from the early evidence of familial clustering to the current state of knowledge with genome-wide approaches. The conclusion is that research efforts have led to a tremendous repository of genetic determinants of asthma, most of which fall into the above phenotypic domains of the syndrome. We now look to future integrative approaches of genetics, genomics (Chap. 10), and epigenetics (Chap. 11) to better understand the causal mechanism through which, these genetic loci act in manifesting asthma.

Genetic predictors of inflammation in the risk of occupational asthma in young apprentices.

BACKGROUND: The influence of genetic predictors of inflammation and atopy on occupational asthma in apprentices is not known. OBJECTIVES: To assess the influence of genetic polymorphisms of IL4RA, IL13, TNFA, IL1A, and IL5 on the decline of lung function and bronchial hyperresponsiveness in a prospective follow-up study of baker/pastry maker and hairdresser apprentices. METHODS: A total of 351 apprentices were included in the study. We performed skin testing, spirometry, fractional exhaled nitric oxide measurement, and methacholine hyperreactivity testing at the initial visit and during and at the end of the 18-month training period. Gene variants of IL4RA, IL13, TNFA, IL1A, and IL5 were determined in DNA from nasal lavage. RESULTS: IL13 R130Q/IL4RA S478P or IL13 R130Q//IL4RA Q551R were significant predictors of the decrease of forced expiratory volume and forced vital capacity (P ≤ .006). Genotype GG of TNFAG308A was associated with bronchial hyperresponsiveness in the whole population and in nonatopic individuals (90.63% vs 9.38%; odds ratio, 3.78; 95% confidence interval, 1.10-12.83). TNFA GA and IL5 CC and TNFA GA and IL1A CC were 2 epistatic predictors of exhaled nitrogen monoxide decrease during follow-up (P = .02 and P = .004, respectively). The association with TNFA GA and IL1A CC was the most significant in nonatopic bakers (P < .001). CONCLUSION: We evidenced a predicting influence of IL13/IL4RA and TNFA in the early exposure to allergens and irritants that precedes occupational asthma. The significance of the associations in the absence of atopy suggests an influence of the genetics predictors related to inflammatory pathways.

A polymorphism in ORMDL3 is associated not only with asthma without rhinitis but also with chronic obstructive pulmonary disease.

BACKGROUND: Asthma is a heterogeneous disease, and asthmatic patients without rhinitis more commonly have fixed airway obstruction, a feature that is also typical of chronic obstructive pulmonary disease (COPD). The Dutch hypothesis suggests that both COPD and asthma have common genetic risk factors. The purpose of this study was to assess the association between the polymorphism rs4795405 in the known asthma candidate gene ORMDL3 and asthma with and without rhinitis. We also analyzed COPD in order to investigate whether, in addition to a clinical overlap, there might also be a genetic overlap between COPD and asthma. METHODS: The population of this genetic association study comprised 493 Slovenian adults, distributed as follows: 131 patients with asthma (59 had asthma with rhinitis and 72 asthma without rhinitis), 59 patients with rhinitis only, 133 patients with COPD, and 170 controls. Genotypes for rs4795405 were determined using the TaqMan genotyping assay. RESULTS: rs4795405 was specifically associated with asthma without rhinitis. Assuming a recessive genetic model, we found the CC genotype in 26% of healthy controls, in 24% of patients with asthma with rhinitis (P = .862), and in 44% of patients with asthma without rhinitis (P = .006). Polymorphism rs4795405 was also associated with COPD, for which the CC genotype was found in 37% of cases (P = .045). CONCLUSIONS: rs4795405 was strongly associated with asthma without rhinitis, a subtype of asthma for which a higher degree of airway obstruction was found. These results show the importance of analyzing different asthma phenotypes in genetic association studies. We also observed a genetic overlap between COPD and asthma without rhinitis.