Project description:Asthma is a chronic inflammatory respiratory disease affecting over 300 million people around the world. Some asthma patients remain poorly controlled by conventional therapies and experience more life-threatening exacerbations. While patients with severe, refractory disease represent a heterogeneous group, a feature shared by most includes glucocorticoid insensitivity. We sought to characterize differences in the airway smooth muscle transcriptome response to glucocorticoids in fatal asthma vs. non-asthma donors. RNA-Seq was used to measure airway smooth muscle transcript expression differences between 9 donors with fatal asthma and 8 non-asthma donors. Cells from each donor were treated with budesonide or with vehicle control. Poly(A)-selected RNA-Seq libraries were prepared with the Illumina TruSeq method. An Illumina HiSeq 2500 instrument was used to generate 125 base pair paired-end reads.
Project description:Rationale: Asthma is a chronic inflammatory airway disease. Children with severe asthma have lower levels of vitamin D than children with moderate asthma, and among children with severe asthma, airway smooth muscle (ASM) mass is inversely related to vitamin D levels. Beta2 agonists are a common asthma medication that act partly by targetting the ASM. We used RNA-Seq to characterize the human ASM transcriptome of fatal and asthma vs. contols at baseline and under two treatment conditions. Methods: The Illumina TruSeq assay was used to prepare 75bp paired-end libraries for ASM cells from white donors, 6 with fatal asthma and 12 control donors under three treatment conditions: 1) no treatment; 2) treatment with a β2-agonist (i.e. Albuterol, 1μM for 18h); 3) treatment with vitamin D 100 nM for 18h). Llibraries were sequenced with an Illumina Hi-Seq 2000 instrument. The Tuxedo Suite Tools were used to align reads to the hg19 reference genome, assemble transcripts, and perform differential expression analysis using the protocol described in https://github.com/blancahimes/taffeta
Project description:Selective stimulation of IL-4 receptor on smooth muscle induces airway hyper-responsiveness in mice. Abstract: Production of the cytokines IL-4 and IL-13 is increased in both human asthma and mouse asthma models and Stat6 activation by the common IL-4/IL-13R drives most mouse model pathophysiology, including airway hyperresponsiveness (AHR). However, the precise cellular mechanisms through which IL-4Rα induces AHR remain unclear. Overzealous bronchial smooth muscle constriction is thought to underlie AHR in human asthma, but the smooth muscle contribution to AHR has never been directly assessed. Furthermore, differences in mouse vs. human airway anatomy and observations that selective IL-13 stimulation of Stat6 in airway epithelium induces murine AHR raise questions about the importance of direct IL-4R effects on smooth muscle in murine asthma models and relevance of these models to human asthma. Using transgenic mice in which smooth muscle is the only cell type that expresses or fails to express IL-4Rα, we demonstrate that direct smooth muscle activation by IL-4, IL-13, or allergen is sufficient, but not necessary, to induce AHR and show that 5 genes known to promote smooth muscle migration, proliferation and contractility are activated by IL-13 in smooth muscle in vivo. These observations demonstrate that IL-4Rα promotes AHR through multiple mechanisms and provide a model for testing smooth muscle-directed asthma therapeutics.
Project description:Selective stimulation of IL-4 receptor on smooth muscle induces airway hyper-responsiveness in mice. Abstract: Production of the cytokines IL-4 and IL-13 is increased in both human asthma and mouse asthma models and Stat6 activation by the common IL-4/IL-13R drives most mouse model pathophysiology, including airway hyperresponsiveness (AHR). However, the precise cellular mechanisms through which IL-4Rα induces AHR remain unclear. Overzealous bronchial smooth muscle constriction is thought to underlie AHR in human asthma, but the smooth muscle contribution to AHR has never been directly assessed. Furthermore, differences in mouse vs. human airway anatomy and observations that selective IL-13 stimulation of Stat6 in airway epithelium induces murine AHR raise questions about the importance of direct IL-4R effects on smooth muscle in murine asthma models and relevance of these models to human asthma. Using transgenic mice in which smooth muscle is the only cell type that expresses or fails to express IL-4Rα, we demonstrate that direct smooth muscle activation by IL-4, IL-13, or allergen is sufficient, but not necessary, to induce AHR and show that 5 genes known to promote smooth muscle migration, proliferation and contractility are activated by IL-13 in smooth muscle in vivo. These observations demonstrate that IL-4Rα promotes AHR through multiple mechanisms and provide a model for testing smooth muscle-directed asthma therapeutics. For the microarray aspect of of the study, there were three groups of mice: 1. IL4R gene knockout (KO) mice 2. WT mice 3. IL4R KO mice that were also transgenic for a gene construct that expressed IL4R under the control of the smooth muscle-specific promoter from the SMP8 gene All mice were subjected to intratracheal IL13 exposure for 7 days, and whole lung RNA was prepared for microarray analysis 24 hours after the last instillation. Per treatment and genotype: Two RNA pools were made from four mice each. These were labeled and hybridized to make a total of 6 microarrays. RNA was labeled with the standard Affymetrix 3' labeling protocol to make cDNA that was hybridized to Mouse MOE 430 plus 2.0 GeneChips. Gene transcripts were identified that differed in their relative expression as a function of IL4R expression on the smooth muscle cells.
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: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 Asthmatic airway smooth muscle cells (ASMC) are intrinsically different and have a differential transcriptional response to pro-fibrotic, pro-proliferation and pro-inflammatory stimuli than ASMC from healthy patients. We sought to identify genes that are differentially expressed between asthmatic and healthy ASMC under various stimulations which mimic the asthmatic airways. To this end, we obtained human ASMC from bronchial biopsies and explanted lungs from doctor diagnosed asthmatic patients (n=3) and healthy controls (n=3). The ASMC were then grown in culture and treated with pro-fibrotic (Transforming growth factor beta (TGFβ)), pro-proliferation (Fetal Bovine Serum (FBS)) and pro-inflammatory stimuli (Interleukin-1 beta (IL-1β)) for 8 hours. Gene expression was then evaluated using Affymetrix Human Gene 1.0ST arrays.
Project description:Asthma is a very frequent airway disease that affects 6 to 20% of the population. Severe asthma, represents 3 to 5% of all asthmatic patients and is histologically characterized by an increased bronchial smooth muscle (BSM) mass and clinically by viral exacerbations. Functionally, BSM remodeling had a poor prognostic value in asthma, since higher BSM mass was associated with lower lung function and increased exacerbation rate. However, the role of BSM as a potential actor of asthma exacerbation has only been sparsely suggested. We thus hypothesis that asthmatic BSM cells could act on bronchial epithelium and modified its response to rhinovirus infection.