Systemic inflammation is associated with differential gene expression and airway neutrophilia in asthma
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ABSTRACT: Systemic inflammation is reported to be associated with neutrophilic airway inflammation in asthma, this study aimed to examine the molecular mechanisms of the neutrophilia that is associated with systemic inflammation, and hypothesized that asthma patients with systemic inflammation have a group of genes that are differentially expressed and are assciated with airway inflammation.
Project description:Systemic inflammation is reported to be associated with neutrophilic airway inflammation in asthma, this study aimed to examine the molecular mechanisms of the neutrophilia that is associated with systemic inflammation, and hypothesized that asthma patients with systemic inflammation have a group of genes that are differentially expressed and are assciated with airway inflammation. 50 asthma patients were recruited and grouped as asthmatics with systemic inflammation (n=18) and asthamtics without systemic inflammation (n=16) accroding to the levels of serum CRP and IL-6. RNA was extracted from induced sputum and was reverse-transcribed into cDNA. Gene profiling was performed using Illumina Sentrix HumanRef-8 Version 2 Expression BeadChips, and genes that were differentially expressed between asthmatics with systemic inflammation and asthmatics without systemic inflammation were compared and valided using qPCR.
Project description:Consumption of a high fat meal can increase neutrophilic airway inflammation in asthma. This study investigates the molecular mechanisms driving airway neutrophilia following a high fat meal in asthma.
Project description:Asthma is a complex, chronic respiratory disease with marked clinical and pathophysiological heterogeneity. Distinct inflammatory phenotypes of eosinophilic, mixed, neutrophilic and paucigranulocytic asthma are identified in patients, but most in vivo mouse models, studying asthma mechanisms, mimic only eosinophilic phenotype in humans. The detailed unbiased in vivo studies on molecular responses among different kinds of inflammation in asthma models are lacking. Therefore, we developed mouse models representing three different inflammatory phenotypes of airway inflammation, namely eosinophilic, mixed, and neutrophilic asthma via different methods of house dust mite sensitisation. We used microarrays to determine the global gene expression in the lungs of mice with eosinophilic, mixed and neutrophilic inflammatory phenotypes to uncover underlying differences in clinical presentation and to find novel molecular targets and pathways, which might reflect different molecular mechanisms of the disease. By whole genome transcriptome profiling, we found that airway tight junction (TJ) molecules, mucins and inflammasome-related genes are differentially expressed in distinct phenotypes of allergic airway inflammation. Next, detailed analysis of several molecules from these families by quantitative RT-PCR, western blot and confocal microscopy revealed that (i) Zo-1 and Cldn18 were downregulated in all phenotypes, while Cldn4 upregulation was characteristic for neutrophilic airway inflammation; (ii) mucins Clca1 (Gob5) and Muc5ac were upregulated in eosinophilic and even more in neutrophilic asthma, and (iii) upregulation of inflammasome-related molecules such as Nlrp3, Nlrc4, Casp-1 and IL-1b was characteristic for neutrophilic asthma. Finally, we showed that inflammasome/Th-17/neutrophilic axis cytokines, namely IL-1b and IL-17 impaired epithelial barrier function and increased mucins expressions in primary human bronchial epithelial cells from normal and asthmatic donors. Our findings suggest that differential expression of TJs, mucins and inflammasome-related molecules in distinct asthma phenotypes could be mechanistically linked and might further reflect the differences observed in the clinic.
Project description:Obesity is associated with severe, difficult to control asthma, and increased airway oxidative stress. Mitochondrial reactive oxygen species (mROS) are an important source of oxidative stress leading us to hypothesize that targeting mROS in obese allergic asthma might be an effective treatment strategy. Using a mouse model of house dust mite (HDM) induced allergic airway disease in mice fed a low- (LFD) or high-fat diet (HFD), and the mitochondrial antioxidant MitoQuinone (MitoQ); we investigated the effects of obesity and mROS on airway inflammation, remodelling and airway hyperreactivity (AHR). HDM induces airway inflammation, remodelling and hyperreactivity in both lean and obese mice. Obese allergic mice showed increased lung tissue eotaxin levels, airway tissue eosinophilia and AHR when compared to lean allergic mice. MitoQ reduced markers of airway inflammation, remodelling and hyperreactivity in both lean and obese allergic mice, and tissue eosinophilia in obeseHDM mice. mROS regulates cell signalling by protein oxidation of multiple downstream targets: MitoQ reduced HDM-induced cysteine-sulfenylation of several proteins including those involved in the unfolded protein response (UPR). In summary, mROS mediates the development of allergic airway disease and hence MitoQ might be effective for the treatment for asthma, and specific features of obese asthma.
Project description:Airway epithelial brushings were obtained for microarray analysis by research bronchoscopy in 62 subjects with mild-to-moderate asthma not on inhaled steroids and 43 healthy controls. Asthma subjects were stratified into 2 subgroups, Th2 high and Th2 low asthma, based on their expression of a three-gene signature of Type 2 inflammation: POSTN, SERPINB2, and CLCA1. Gene expression comparisons were made between: 1. asthmatics and healthy controls, and 2. Th2 high asthma and Th2 Low asthma/Healthy controls. The gene expression alterations most associated with asthma were then used in gene set enrichment analyses and gene signature development to compare this asthma dataset to COPD gene expression datasets.
Project description:We performed genome-wide profiling of miRNA expression in the airway epithelial compartment in asthma to identify miRNA pathways associated with epithelial abnormalities using miRNA microarrays and real-time PCR. We also sought to identify the effect of inhaled corticosteroids (ICS) on airway epithelial miRNA expression Samples were obtained from airway epithelial cells by bronchoscopic brushing from three groups of subjects: Healthy Controls ( N=12), Steroid Naïve Asthma (N=16), Steroid-requiring Asthma (N=19).
Project description:Many neutrophilic asthma patients do not respond to current medications, highlighting the need for novel therapeutic targets. Here, we investigated the role of intraflagellar transport (IFT) complex protein IFT20 in neutrophilic asthma. Mice lacking CD4+ T cell-specific IFT20 displayed reduced protease-induced neutrophilic asthma inflammation. Thus, IFT20 may represent a promising therapeutic target for treatment of patients with neutrophilic asthma.
Project description:Airway epithelial brushings were obtained for microarray analysis by research bronchoscopy in 62 subjects with mild-to-moderate asthma not on inhaled steroids and 43 healthy controls. Asthma subjects were stratified into 2 subgroups, Th2 high and Th2 low asthma, based on their expression of a three-gene signature of Type 2 inflammation: POSTN, SERPINB2, and CLCA1.
Project description:Airway remodeling is a main pathological feature of asthma. The current therapy for asthma is mainly targeted for reducing inflammation, not particularly for airway remodeling. Herein, developing alternative and more effective therapy to attenuate remodeling is worthy of further study. Gu-Ben-Fang-Xiao Decoction (GBFXD) has been used to treat asthma for decades effectively and safely. In present study, GBFXD significantly regulated the airway inflammation, collagen deposition and the molecules relevant to airway remodeling such as Vimentin, α-SMA, hydroxyproline (HYP), and E-cadherin in chronic remission asthma (CRA) murine model. Subsequently, we found the overlapping differentially expressed proteins (DEPs) between Model/Control and GBFXD/Model mainly belonged to Collagen and Laminin which were extracellular matrix (ECM) proteins by iTRAQ proteomics. In addition, the KEGG analysis showed GBFXD could regulate pathways related to airway remodeling, such as ECM-receptor interaction, Focal adhesion, and PI3K/AKT signaling pathway which were top three pathways of most DEPs (Model/Control and GBFXD/Model) significantly enriched simultaneously. Further validation research showed GBFXD regulated Reticulon-4 (RTN4), thus suppressing the activation of PI3K/AKT pathway to alleviate the ECM proteins deposition. Thus, our findings indicate GBFXD regulate the PI3K/AKT pathway via RTN4 to improve airway remodeling and provide a new insight into the molecular mechanism of GBFXD for treating CRA.