Fatal Asthma vs. Control Human Airway Smooth Muscle Transcriptome Changes in Response to Vitamin D or Albuterol
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ABSTRACT: 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:Rationale: Asthma is a chronic inflammatory airway disease. The most common medications used for its treatment are β2-agonists and glucocorticosteroids, and one of the primary tissues that these drugs target in the treatment of asthma is the airway smooth muscle. We used RNA-Seq to characterize the human airway smooth muscle (HASM) transcriptome at baseline and under three asthma treatment conditions. Methods: The Illumina TruSeq assay was used to prepare 75bp paired-end libraries for HASM cells from four white male donors under four treatment conditions: 1) no treatment; 2) treatment with a β2-agonist (i.e. Albuterol, 1μM for 18h); 3) treatment with a glucocorticosteroid (i.e. Dexamethasone (Dex), 1μM for 18h); 4) simultaneous treatment with a β2-agonist and glucocorticoid, and the libraries 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:Rationale: Asthma is a chronic inflammatory airway disease. The most common medications used for its treatment are β2-agonists and glucocorticosteroids, and one of the primary tissues that these drugs target in the treatment of asthma is the airway smooth muscle. We used RNA-Seq to characterize the human airway smooth muscle (HASM) transcriptome at baseline and under three asthma treatment conditions. Methods: The Illumina TruSeq assay was used to prepare 75bp paired-end libraries for HASM cells from four white male donors under four treatment conditions: 1) no treatment; 2) treatment with a β2-agonist (i.e. Albuterol, 1μM for 18h); 3) treatment with a glucocorticosteroid (i.e. Dexamethasone (Dex), 1μM for 18h); 4) simultaneous treatment with a β2-agonist and glucocorticoid, and the libraries 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 mRNA profiles obtained via RNA-Seq for four primary human airway smooth muscle cell lines that were treated with dexamethasone, albuterol, dexamethasone+albuterol or were left untreated.
Project description:Background: Increased proliferation of airway smooth muscle (ASM) cells leading to hyperplasia and increased ASM mass is one of the most characteristic features of airway remodelling in asthma. A bioactive lipid, sphingosine-1-phosphate (S1P), has been suggested to affect airway remodelling by stimulation of human ASM cell proliferation. Objective: To investigate the effect of S1P on signalling and regulation of gene expression in ASM cells from healthy and asthmatic individuals. Methods: ASM cells grown from bronchial biopsies of healthy and asthmatic individuals were exposed to S1P. Gene expression was analysed using microarray, real-time PCR and western blotting. Receptor signalling and function was determined by mRNA knockdown and intracellular calcium mobilisation experiments. Results: S1P potently regulated the expression of more than 80 genes in human ASM cells, including several genes known to be involved in the regulation of cell proliferation and airway remodelling (HBEGF, TGFB3, TXNIP, PLAUR, SERPINE1, RGS4). S1P acting through S1P2 and S1P3 receptors activated intracellular calcium mobilisation and extracellular signal-regulated and Rho-associated kinases to regulate gene expression. S1P-induced responses were not inhibited by corticosteroids and did not differ significantly between ASM cells from healthy and asthmatic individuals. Conclusion: S1P induces a steroid-resistant, pro-remodelling pathway in ASM cells. Targeting S1P or its receptors could be a novel treatment strategy for inhibiting airway remodelling in asthma. Airway smooth muscle cells from 3 healthy donors were cultured and stimulated for 4 h with sphingosine-1-phosphate (100 nM) or medium control. Total RNA was extracted and analysed using Affymetrix Human Exon 1.0 ST arrays.
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:Glucocorticoids (GCs) and protein kinase A (PKA)-activating agents (beta-adrenergic receptor agonists) are mainstream asthma therapies based on their ability to prevent or reverse excessive airway smooth muscle (ASM) constriction. Their abilities to regulate another important feature of asthma - excessive ASM growth are poorly understood. Recent studies have suggested that GCs render agents of inflammation such as interleukin 1beta and tumor necrosis factor alpha mitogenic to ASM, via suppression of (antimitogenic) induced cyclooxygenase-2-dependent PKA activity. To further explore the mechanistic basis of these observations, we assessed the effects of epidermal growth factor and interleukin 1beta stimulation, and the modulatory effects of GC treatment and PKA inhibition, on the ASM transcriptome by microarray analysis. Experiment Overall Design: Human ASM cultures were generated from trachea of 4 unidentified donors and used in passage 5-8. These cells were used to generate cells stabely expressing a PKA inhibitor (PKI) or GFP (control), which were then grown to confluence, serum starved for 24h, and stimulated with IL-1b, EGF,or both (E+I) in presence or absence of Fluticasone (Flu, 30 min pretreatment). After 8h stimulation cells were washed and total RNA isolated using TRIzol as per manufacturer's protocol. Gene expression was analyzed in 4 different cultures derived from 4 different donors (for a total of 3-4 microarrays per condition).
Project description:Severe asthma induces substantial mortality and chronic disability due to intractable airway obstruction, which may become resistant to currently available therapies including corticosteroids and b-adrenergic agonist bronchodilators. A key effector of these changes is exaggerated airway smooth muscle (ASM) cell contraction to spasmogens. Unfortunately, no drugs in clinical use effectively prevent ASM hyperresponsiveness in asthma across all severities. Here we show that N-cadherin, a plasma membrane associated cell-cell adhesion protein upregulated in ASM cells derived from patients with severe asthma, is required for the development of airway obstruction induced by allergic airway inflammation in mice. Pharmacological inhibition of N-cadherin by ADH-1 reduced airway hyperresponsiveness independent of allergic inflammation. ADH-1 prevented bronchoconstriction and actively promoted bronchodilation of airways ex vivo. In human ASM cells, ADH-1 inhibited agonist-induced contraction by disrupting N-cadherin-d-catenin interactions, which decreased intracellular actin remodeling. These data provide evidence for an intercellular communication pathway mediating ASM contraction and identify N-cadherin as a potential therapeutic target for inhibiting bronchoconstriction in asthma.
Project description:Background: Increased proliferation of airway smooth muscle (ASM) cells leading to hyperplasia and increased ASM mass is one of the most characteristic features of airway remodelling in asthma. A bioactive lipid, sphingosine-1-phosphate (S1P), has been suggested to affect airway remodelling by stimulation of human ASM cell proliferation. Objective: To investigate the effect of S1P on signalling and regulation of gene expression in ASM cells from healthy and asthmatic individuals. Methods: ASM cells grown from bronchial biopsies of healthy and asthmatic individuals were exposed to S1P. Gene expression was analysed using microarray, real-time PCR and western blotting. Receptor signalling and function was determined by mRNA knockdown and intracellular calcium mobilisation experiments. Results: S1P potently regulated the expression of more than 80 genes in human ASM cells, including several genes known to be involved in the regulation of cell proliferation and airway remodelling (HBEGF, TGFB3, TXNIP, PLAUR, SERPINE1, RGS4). S1P acting through S1P2 and S1P3 receptors activated intracellular calcium mobilisation and extracellular signal-regulated and Rho-associated kinases to regulate gene expression. S1P-induced responses were not inhibited by corticosteroids and did not differ significantly between ASM cells from healthy and asthmatic individuals. Conclusion: S1P induces a steroid-resistant, pro-remodelling pathway in ASM cells. Targeting S1P or its receptors could be a novel treatment strategy for inhibiting airway remodelling in asthma.
Project description:Rationale: Asthma and atopy shares common features including Th2-inflammation. However, impairment of airway function seems to be absent in atopy. Increased understanding of the complex cellular and molecular pathways defining the similarities and differences between asthma and atopy may be achieved by transcriptomic analysis (RNA-Seq). Hypothesis and Aims: As the airway smooth muscle (ASM) layer plays an important role in airway function, we hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies is different between atopic asthma patients and atopic healthy controls. First, we examined the differences in transcriptomic profiles of the ASM layer in endobronchial biopsies between atopic mild, steroid-free asthma patients, and atopic and non-atopic healthy controls. Second, we investigated the association between the transcriptomic profiles of the ASM layer and airway function. Methods: This cross-sectional study included 12 steroid-free atopic asthma patients, 6 atopic, and 6 non-atopic healthy controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 1%. Results: Yield of isolated RNA was 30-821ng. We identified 174 differentially expressed genes between asthma and atopic controls, 108 between asthma and non-atopic controls, and 135 between atopic and non-atopic controls. A set of 8 genes was identified, which seems to define asthma patients from non-asthmatic controls regardless of atopy. Four of these genes were significantly associated with airway hyperresponsiveness. Conclusion: A difference in transcriptomic profile of the airway smooth muscle layer in asthma patients compared to atopic and non-atopic healthy controls may lead to a different regulation of inflammatory pathways and of airway smooth muscle function and development resulting in impaired airway function. This cross-sectional transcriptomics study consisted of 2 visits. At visit 1, asthma patients (n=12), and healthy atopic (n=6) and non-atopic (n=6) controls were screened for eligibility to participate according to the in- and exclusion criteria. Spirometry and a methacholine bronchoprovocation test were performed. At visit 2, FEV1 reversibility was measured and 4 endobronchial biopsies per subject were collected during a bronchoscopy. Airway smooth muscle was collected from the biopsies by laser capture microdissection and total RNA isolated. cDNA was prepared using the Ovation RNA-Seq System (NuGEN). RNA-Seq was performed using the GS FLX+ instrument (454/Roche). Sequence reads were mapped against the human genome (hg19; UCSC). Comparison of the numbers of reads per gene between asthma and healthy controls was based on the negative binomial distribution and carried out with the R package DESeq including correction for multiple testing.
Project description:Rationale: Asthma and atopy shares common features including Th2-inflammation. However, impairment of airway function seems to be absent in atopy. Increased understanding of the complex cellular and molecular pathways defining the similarities and differences between asthma and atopy may be achieved by transcriptomic analysis (RNA-Seq). Hypothesis and Aims: As the airway smooth muscle (ASM) layer plays an important role in airway function, we hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies is different between atopic asthma patients and atopic healthy controls. First, we examined the differences in transcriptomic profiles of the ASM layer in endobronchial biopsies between atopic mild, steroid-free asthma patients, and atopic and non-atopic healthy controls. Second, we investigated the association between the transcriptomic profiles of the ASM layer and airway function. Methods: This cross-sectional study included 12 steroid-free atopic asthma patients, 6 atopic, and 6 non-atopic healthy controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 1%. Results: Yield of isolated RNA was 30-821ng. We identified 174 differentially expressed genes between asthma and atopic controls, 108 between asthma and non-atopic controls, and 135 between atopic and non-atopic controls. A set of 8 genes was identified, which seems to define asthma patients from non-asthmatic controls regardless of atopy. Four of these genes were significantly associated with airway hyperresponsiveness. Conclusion: A difference in transcriptomic profile of the airway smooth muscle layer in asthma patients compared to atopic and non-atopic healthy controls may lead to a different regulation of inflammatory pathways and of airway smooth muscle function and development resulting in impaired airway function.
Project description:Glucocorticoids (GCs) and protein kinase A (PKA)-activating agents (beta-adrenergic receptor agonists) are mainstream asthma therapies based on their ability to prevent or reverse excessive airway smooth muscle (ASM) constriction. Their abilities to regulate another important feature of asthma - excessive ASM growth are poorly understood. Recent studies have suggested that GCs render agents of inflammation such as interleukin 1beta and tumor necrosis factor alpha mitogenic to ASM, via suppression of (antimitogenic) induced cyclooxygenase-2-dependent PKA activity. To further explore the mechanistic basis of these observations, we assessed the effects of epidermal growth factor and interleukin 1beta stimulation, and the modulatory effects of GC treatment and PKA inhibition, on the ASM transcriptome by microarray analysis. Keywords: gene expression