Project description:Management of severe asthma remains a challenge despite treatment with glucocorticosteroid therapy. The majority of studies investigating disease mechanisms in treatment-resistant severe asthma have previously focused on the large central airways, with very few utilizing transcriptomic approaches. The small peripheral airways, which comprise the majority of the airway surface area, remain an unexplored area in severe asthma and were targeted for global epithelial gene expression profiling in this study.
Project description:Ozone is a very common environmental pollutant and has been associated with the exacerbation of cardiopulmonary diseases like asthma. In this study the molecular mechanisms underlying the effect of ozone on airways hyperpermability were investigated. Two strains of mice, HeJ (Tlr4 mutant) and OuJ (wildtype) were exposed continuously to air or 0.3ppm of ozone. Lungs were removed and RNA was collected to generate expression profiles. Keywords: other
Project description:Persistent severe asthma is associated with hyper-contractile airways and structural changes in the airway wall, including an increased airway smooth muscle (ASM) mass. This study used gene expression profiles from asthmatic and healthy airway smooth muscle cells grown in culture to identify novel receptors and pathways that potentially contributed to asthma pathogenesis. We used microarrays to compare the gene expression between asthmatic and healthy airway smooth muscle cells to understand the underlying pathway contributing the differences in cellular phenotypes
Project description:Maternal asthma (MA) is among the most consistent risk factors for asthma in her children. Possible mechanisms for this observation are epigenetic modifications in utero that have lasting effects on developmental programs in children of mothers with asthma. To test this hypothesis, we performed differential DNA methylation analyses of 398,186 individual CpG sites in primary bronchial epithelial cells (BECs) from 42 non-asthma controls and 88 asthma cases, including 56 without MA (NMA) and 32 with MA. We used weighted gene co-expression network analysis (WGCNA) of 69 and 554 differentially methylated CpGs (DMCs) that were specific to NMA or MA cases, respectively, compared to controls. WGCNA grouped 66 NMA-DMCs and 203 MA-DMCs into two and five co-methylation modules, respectively. The eigenvector of one MA-associated module (turquoise) was uniquely correlated with 85 genes expressed in BECs and enriched for 36 pathways, 16 of which discriminated between NMA and MA using machine learning. Genes in all 16 pathways were decreased in MA compared to NMA cases (P=7.1x10-3), a finding that replicated in nasal epithelial cells from an independent cohort (P=0.02). Functional interpretation of these pathways suggested impaired T cell signaling and responses to viral and bacterial pathogens. The MA-associated turquoise module eigenvector was additionally correlated with clinical features of severe asthma and reflective of type 2 (T2)-low asthma (i.e., low total serum IgE, fractional exhaled nitric oxide, and eosinophilia). Overall, these data suggest that maternal asthma alters diverse epigenetically-mediated pathways that lead to distinct subtypes of severe asthma in adults including hard-to-treat T2-low asthma.
Project description:Maternal asthma (MA) is among the most consistent risk factors for asthma in her children. Possible mechanisms for this observation are epigenetic modifications in utero that have lasting effects on developmental programs in children of mothers with asthma. To test this hypothesis, we performed differential DNA methylation analyses of 398,186 individual CpG sites in primary bronchial epithelial cells (BECs) from 42 non-asthma controls and 88 asthma cases, including 56 without MA (NMA) and 32 with MA. We used weighted gene co-expression network analysis (WGCNA) of 69 and 554 differentially methylated CpGs (DMCs) that were specific to NMA or MA cases, respectively, compared to controls. WGCNA grouped 66 NMA-DMCs and 203 MA-DMCs into two and five co-methylation modules, respectively. The eigenvector of one MA-associated module (turquoise) was uniquely correlated with 85 genes expressed in BECs and enriched for 36 pathways, 16 of which discriminated between NMA and MA using machine learning. Genes in all 16 pathways were decreased in MA compared to NMA cases (P=7.1x10-3), a finding that replicated in nasal epithelial cells from an independent cohort (P=0.02). Functional interpretation of these pathways suggested impaired T cell signaling and responses to viral and bacterial pathogens. The MA-associated turquoise module eigenvector was additionally correlated with clinical features of severe asthma and reflective of type 2 (T2)-low asthma (i.e., low total serum IgE, fractional exhaled nitric oxide, and eosinophilia). Overall, these data suggest that maternal asthma alters diverse epigenetically-mediated pathways that lead to distinct subtypes of severe asthma in adults including hard-to-treat T2-low asthma.
Project description:By incompletely understood mechanisms, type 2 (T2) inflammation present in the airways of severe asthmatics drives the formation of pathologic mucus which leads to airway mucus plugging. Here we investigate the molecular role and clinical significance of intelectin-1 (ITLN-1) in the development of pathologic airway mucus in asthma. Through analyses of human airway epithelial cells we find that ITLN1 gene expression is highly induced by interleukin-13 (IL-13) in a subset of metaplastic MUC5AC+ mucus secretory cells, and that ITLN-1 protein is a secreted component of IL-13-induced mucus. Additionally, we find ITLN-1 protein binds the C-terminus of the MUC5AC mucin and that its deletion in airway epithelial cells partially reverses IL-13-induced mucostasis. Through analysis of nasal airway epithelial brushings, we find that ITLN1 is highly expressed in T2-high asthmatics, when compared to T2-low children. Furthermore, we demonstrate that ITLN1 gene expression is significantly reduced and ITLN-1 protein expression is lost through a common genetic variant that is associated with protection from the formation of mucus plugs in T2-high asthma. This work identifies one of the first biomarkers and targetable pathways for the treatment of mucus obstruction in asthma.
Project description:Asthma is multi-factorial disorder, and microbial dysbiosis enhances lung inflammation and asthma-related symptoms. Probiotics has shown anti-inflammatory effect and could regulate the gut-lung axis. Thus, a three-month randomized, double-blind, and placebo-controlled human trial was performed to investigate the adjunctive efficacy of probiotics in managing asthma.
Project description:The exacerbation of disease in asthmatics has been linked to both exposure to environmental agents as well as to the presence of virus in airways, particularly rhinovirus. The hypothesis tested in these experiments is that differences in gene expression profiles in epithelial cells derived from asthmatic and normal airways can be linked to enhanced responsiveness of the epithelium in its pro-inflammatory, immulogic or other activities that may lead to the exacerbation of disease.
Project description:Inhaled corticosteroids (ICS) control airway inflammation in mild to moderate asthma by reducing inflammatory gene expression. However, incomplete understanding of the molecular mechanisms underpinning corticosteroid action hinders development of improved therapies for more severe disease. Microarray analysis was performed on RNA from biopsies taken from healthy individuals after receiving single dose of ICS to characterize corticosteroid-induced modulation of gene expression in the human airways.