title: Quantitative proteomics reveals an altered cystic fibrosis in vitro bronchial epithelial secretome.
abstract: Alterations in epithelial secretions and mucociliary clearance contribute to chronic bacterial infection in cystic fibrosis (CF) lung disease, but whether CF lungs are unchanged in the absence of infection remains controversial. A proteomic comparison of airway secretions from subjects with CF and control subjects shows alterations in key biological processes, including immune response and proteolytic activity, but it is unclear if these are due to mutant CF transmembrane conductance regulator (CFTR) and/or chronic infection. We hypothesized that the CF lung apical secretome is altered under constitutive conditions in the absence of inflammatory cells and pathogens. To test this, we performed quantitative proteomics of in vitro apical secretions from air-liquid interface cultures of three life-extended CF (ΔF508/ΔF508) and three non-CF human bronchial epithelial cells after labeling of CF cells by stable isotope labeling with amino acids in cell culture. Mass spectrometry analysis identified and quantitated 666 proteins across samples, of which 70 exhibited differential enrichment or depletion in CF secretions (±1.5-fold change; P < 0.05). The key molecular functions were innate immunity (24%), cytoskeleton/extracellular matrix organization (24%), and protease/antiprotease activity (17%). Oxidative proteins and classical complement pathway proteins that are altered in CF secretions in vivo were not altered in vitro. Specific differentially increased proteins-MUC5AC and MUC5B mucins, fibronectin, and matrix metalloproteinase-9-were validated by antibody-based assays. Overall, the in vitro CF secretome data are indicative of a constitutive airway epithelium with altered innate immunity, suggesting that downstream consequences of mutant CFTR set the stage for chronic inflammation and infection in CF airways.
authors.affiliation: Departments of 1 Integrative Systems Biology and.|2 Research Center for Genetic Medicine and.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Peters-Hall
authors.affiliation: Departments of 1 Integrative Systems Biology and.|3 Pediatrics, George Washington University School of Medicine, Washington, DC; and.|2 Research Center for Genetic Medicine and.
authors.forename: Kristy J
authors.initials: KJ
authors.lastname: Brown
authors.affiliation: Departments of 1 Integrative Systems Biology and.|3 Pediatrics, George Washington University School of Medicine, Washington, DC; and.|2 Research Center for Genetic Medicine and.|4 Division of Pulmonary and Sleep Medicine, Children's National, Washington, DC.
authors.forename: Dinesh K
authors.initials: DK
authors.lastname: Pillai
authors.affiliation: 2 Research Center for Genetic Medicine and.
authors.forename: Amarel
authors.initials: A
authors.lastname: Tomney
authors.affiliation: Departments of 1 Integrative Systems Biology and.|2 Research Center for Genetic Medicine and.
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Garvin
authors.affiliation: Departments of 1 Integrative Systems Biology and.|3 Pediatrics, George Washington University School of Medicine, Washington, DC; and.|2 Research Center for Genetic Medicine and.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Wu
authors.affiliation: Departments of 1 Integrative Systems Biology and.|3 Pediatrics, George Washington University School of Medicine, Washington, DC; and.|2 Research Center for Genetic Medicine and.
authors.forename: Mary C
authors.initials: MC
authors.lastname: Rose
mesh_terms: D001980:Bronchi / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D002908:Chronic Disease; D003550:Cystic Fibrosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D020545:Respiratory Mucosa / Q000378:metabolism* / Q000473:pathology
chemical_list: D020543:Proteome
keywords: bronchial epithelial secretions; cystic fibrosis; innate immunity; quantitative proteomics; secretome