Natasha A Winter1, Ling Qin2, Peter G Gibson3, Vanessa M McDonald4, Katherine J Baines5, Jack Faulkner6, Tiffany-Jane Evans6, Michael Fricker7. 1. National Health and Medical Research Council Centre for Research Excellence in Severe Asthma, Newcastle, Australia; The Priority Research Centre for Health Lungs, The University of Newcastle, Newcastle, Australia; School of Medicine and Public Health, The University of Newcastle, Newcastle, Australia. 2. Department of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, China. 3. National Health and Medical Research Council Centre for Research Excellence in Severe Asthma, Newcastle, Australia; The Priority Research Centre for Health Lungs, The University of Newcastle, Newcastle, Australia; School of Medicine and Public Health, The University of Newcastle, Newcastle, Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, Hunter Medical Research Institute, Newcastle, Australia. 4. National Health and Medical Research Council Centre for Research Excellence in Severe Asthma, Newcastle, Australia; The Priority Research Centre for Health Lungs, The University of Newcastle, Newcastle, Australia; School of Nursing and Midwifery, The University of Newcastle, Newcastle, Australia. 5. The Priority Research Centre for Health Lungs, The University of Newcastle, Newcastle, Australia. 6. Clinical Research Design, IT and Statistical Support Unit, Hunter Medical Research Institute, Newcastle, Australia. 7. National Health and Medical Research Council Centre for Research Excellence in Severe Asthma, Newcastle, Australia; The Priority Research Centre for Health Lungs, The University of Newcastle, Newcastle, Australia; School of Medicine and Public Health, The University of Newcastle, Newcastle, Australia. Electronic address: Michael.Fricker@newcastle.edu.au.
Abstract
BACKGROUND: Mast cells (MCs) and basophils are important in asthma pathophysiology, however direct measurement is difficult, and clinical and inflammatory associations in severe asthma are poorly understood. Transcriptomic hallmarks of MCs/basophils may allow their measurement in sputum using gene expression. OBJECTIVES: This study sought to develop and validate a sputum MC/basophil gene signature and investigate its relationship to inflammatory and clinical characteristics of severe asthma. METHODS: A total of 134 candidate MC/basophil genes (identified by the Immunological Genome Project Consortium) were screened in sputum microarray for differential expression among control subjects (n = 18), patients with eosinophilic (n = 29), and patients with noneosinophilic asthma (n = 30). Candidate genes were validated by confirming correlation of gene expression with flow cytometry-quantified sputum MCs and basophils in a separate asthma cohort (n = 20). The validated gene signature was measured in a severe asthma cohort (n = 81), and inflammatory and clinical associations were tested. RESULTS: Through microarray screening and subsequent validation, we found quantitative PCR gene expression of 8 targets correlated with sputum MCs/basophils: TPSAB1/TPSB2, CPA3, ENO2, GATA2, KIT, GPR56, HDC, SOCS2. In severe asthma, MC/basophil genes were associated with eosinophilic airway inflammation (GATA2, TPSB2, CPA3, GPR56, HDC, SOCS2), blood eosinophils (TPSB2, CPA3, GATA2, SOCS2, FCER1A, HDC), fractional exhaled NO (GATA2, SOCS2), decreased lung function (KIT, ENO2), and moderate exacerbation history (GATA2, SOCS2). CONCLUSIONS: Quantitative PCR-based measures reflect varying sputum MC/basophil abundance, demonstrating associations of MCs/basophils with eosinophilic inflammation, spirometry and exacerbation history in severe asthma.
BACKGROUND: Mast cells (MCs) and basophils are important in asthma pathophysiology, however direct measurement is difficult, and clinical and inflammatory associations in severe asthma are poorly understood. Transcriptomic hallmarks of MCs/basophils may allow their measurement in sputum using gene expression. OBJECTIVES: This study sought to develop and validate a sputum MC/basophil gene signature and investigate its relationship to inflammatory and clinical characteristics of severe asthma. METHODS: A total of 134 candidate MC/basophil genes (identified by the Immunological Genome Project Consortium) were screened in sputum microarray for differential expression among control subjects (n = 18), patients with eosinophilic (n = 29), and patients with noneosinophilic asthma (n = 30). Candidate genes were validated by confirming correlation of gene expression with flow cytometry-quantified sputum MCs and basophils in a separate asthma cohort (n = 20). The validated gene signature was measured in a severe asthma cohort (n = 81), and inflammatory and clinical associations were tested. RESULTS: Through microarray screening and subsequent validation, we found quantitative PCR gene expression of 8 targets correlated with sputum MCs/basophils: TPSAB1/TPSB2, CPA3, ENO2, GATA2, KIT, GPR56, HDC, SOCS2. In severe asthma, MC/basophil genes were associated with eosinophilic airway inflammation (GATA2, TPSB2, CPA3, GPR56, HDC, SOCS2), blood eosinophils (TPSB2, CPA3, GATA2, SOCS2, FCER1A, HDC), fractional exhaled NO (GATA2, SOCS2), decreased lung function (KIT, ENO2), and moderate exacerbation history (GATA2, SOCS2). CONCLUSIONS: Quantitative PCR-based measures reflect varying sputum MC/basophil abundance, demonstrating associations of MCs/basophils with eosinophilic inflammation, spirometry and exacerbation history in severe asthma.
Authors: Nicolas Castaño; Sungu Kim; Adrian M Martin; Stephen J Galli; Kari C Nadeau; Sindy K Y Tang Journal: Lab Chip Date: 2022-05-03 Impact factor: 7.517
Authors: Dmitri Atiakshin; Andrey Kostin; Ivan Trotsenko; Vera Samoilova; Igor Buchwalow; Markus Tiemann Journal: Cells Date: 2022-02-06 Impact factor: 6.600