BACKGROUND: Airway remodeling in patients with severe steroid-refractory asthma might result from a reduced ability of steroid therapy to limit the transcription of remodeling factors by the bronchial epithelium. OBJECTIVE: We sought to compare the levels of transcripts encoding remodeling factors in bronchial epithelium of healthy volunteers and of asthmatic patients with either steroid-sensitive or steroid-refractory disease and to correlate these levels with hallmarks of airway remodeling. METHODS: By means of real-time quantitative PCR, we assessed the levels of 14 transcripts encoding remodeling factors, matrix metalloproteinases, and extracellular matrix proteins in laser-capture microdissected bronchial epithelium of healthy volunteers, patients with mild steroid-untreated asthma, and patients with steroid-sensitive and steroid-refractory asthma (n = 8-10 in each group). Histologic features of airway remodeling and endothelin-1 (EDN1) immunolocalization were determined by using frozen specimens. RESULTS: Patients with steroid-refractory asthma had greater levels of EDN1 transcripts (4.1-fold increase, P = .026) and protein (P = .0009) in their bronchial epithelium compared with patients with steroid-sensitive asthma. EDN1 mRNA levels and protein expression in asthmatic patients were negatively correlated with prebronchodilator and postbronchodilator FEV(1) value (r(2) >or= 0.193, P <or= .03), and they were positively related to airway smooth muscle areas (r(2) = 0.253, P = .01 and r(2) = 0.281, P = .005 for EDN1 mRNA and protein expression, respectively). CONCLUSION: Increased EDN1 synthesis by the bronchial epithelium characterizes severe refractory asthma and correlates with airway remodeling and airflow obstruction. CLINICAL IMPLICATIONS: Targeting EDN1 might represent a novel therapeutic strategy for severe steroid-refractory asthma.
BACKGROUND: Airway remodeling in patients with severe steroid-refractory asthma might result from a reduced ability of steroid therapy to limit the transcription of remodeling factors by the bronchial epithelium. OBJECTIVE: We sought to compare the levels of transcripts encoding remodeling factors in bronchial epithelium of healthy volunteers and of asthmatic patients with either steroid-sensitive or steroid-refractory disease and to correlate these levels with hallmarks of airway remodeling. METHODS: By means of real-time quantitative PCR, we assessed the levels of 14 transcripts encoding remodeling factors, matrix metalloproteinases, and extracellular matrix proteins in laser-capture microdissected bronchial epithelium of healthy volunteers, patients with mild steroid-untreated asthma, and patients with steroid-sensitive and steroid-refractory asthma (n = 8-10 in each group). Histologic features of airway remodeling and endothelin-1 (EDN1) immunolocalization were determined by using frozen specimens. RESULTS:Patients with steroid-refractory asthma had greater levels of EDN1 transcripts (4.1-fold increase, P = .026) and protein (P = .0009) in their bronchial epithelium compared with patients with steroid-sensitive asthma. EDN1 mRNA levels and protein expression in asthmatic patients were negatively correlated with prebronchodilator and postbronchodilator FEV(1) value (r(2) >or= 0.193, P <or= .03), and they were positively related to airway smooth muscle areas (r(2) = 0.253, P = .01 and r(2) = 0.281, P = .005 for EDN1 mRNA and protein expression, respectively). CONCLUSION: Increased EDN1 synthesis by the bronchial epithelium characterizes severe refractory asthma and correlates with airway remodeling and airflow obstruction. CLINICAL IMPLICATIONS: Targeting EDN1 might represent a novel therapeutic strategy for severe steroid-refractory asthma.
Authors: Jane E Bourke; Yan Bai; Chantal Donovan; James G Esposito; Xiahui Tan; Michael J Sanderson Journal: Am J Respir Cell Mol Biol Date: 2014-04 Impact factor: 6.914
Authors: Erik Melén; Alvin T Kho; Sunita Sharma; Roger Gaedigk; J Steven Leeder; Thomas J Mariani; Vincent J Carey; Scott T Weiss; Kelan G Tantisira Journal: Respir Res Date: 2011-06-23
Authors: Ariane H Wagener; Aeilko H Zwinderman; Silvia Luiten; Wytske J Fokkens; Elisabeth H Bel; Peter J Sterk; Cornelis M van Drunen Journal: PLoS One Date: 2013-11-25 Impact factor: 3.240