title: S100A7/psoriasin expression in the human lung: unchanged in patients with COPD, but upregulated upon positive S. aureus detection.
abstract: BACKGROUND
  Progressive airway inflammation and susceptibility to the airway colonisation and infection are characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). Antimicrobial peptides (AMPs) are central to the function of the innate host immune response against microbial pathogens and are regulators of inflammation and immunity. S100A7/psoriasin, a recently described AMP, is an essential component of the human epithelia against invading pathogens and acts as an effector molecule of the host innate defence in the skin. We hypothesized that S100A7/psoriasin is involved in the airway mucosal immunity and differently regulated and expressed in the lung during progression of COPD.
  
  
  METHODS
  S100A7/psoriasin gene expression was assessed in bronchial biopsies and bronchoalveolar lavage (BAL) fluid cells of healthy controls and COPD patients. Using confocal microscopy and immunohistochemistry, the protein expression of S100A7/psoriasin was investigated.
  
  
  RESULTS
  Here, we report that S100A7/psoriasin, the major antimicrobial peptide of the human skin, is constitutively expressed in perinuclear granules of human bronchial epithelial cells and alveolar macrophages. Whereas typical activators of the innate immune response like TLR ligands and cytokines induced the upregulation of CXCL-8 mRNA and release of CXCL-8 by epithelial cells, S100A7/psoriasin mRNA expression was not modulated. To investigate a potential association of S100A7/psoriasin with COPD, S100A7/psoriasin mRNA expression was assessed in bronchial biopsies and BAL fluid cells of patients at different stages of COPD and controls. Overall, 10 healthy individuals and 34 COPD patients were enrolled in this study. We found an association of S100A7/psoriasin mRNA expression with bacterial detection in the tracheobronchial system (p = 0.0304), which was the strongest in individuals positive for with S. aureus (p = 0.0005). However, S100A7/psoriasin mRNA expression was not altered during the progression of COPD.
  
  
  CONCLUSIONS
  S100A7/psoriasin gene expression is unchanged in the airways during COPD. The newly identified association of S100A7/psoriasin with S. aureus may provide new insights into the antimicrobial defence response of the human airways, leading to the induction of S100A7/psoriasin upon microbial challenge.
authors.affiliation: Division of Innate Immunity, Department of Immunology and Cell Biology, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 1-40, 23845 Borstel, Germany. hheine@fz-borstel.de.
authors.forename: Ellen
authors.initials: E
authors.lastname: Andresen
authors.forename: Christoph
authors.initials: C
authors.lastname: Lange
authors.forename: Daniela
authors.initials: D
authors.lastname: Strodthoff
authors.forename: Torsten
authors.initials: T
authors.lastname: Goldmann
authors.forename: Nicole
authors.initials: N
authors.lastname: Fischer
authors.forename: Hany
authors.initials: H
authors.lastname: Sahly
authors.forename: Detlev
authors.initials: D
authors.lastname: Branscheid
authors.forename: Holger
authors.initials: H
authors.lastname: Heine
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001980:Bronchi / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology; D008168:Lung / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D000075023:S100 Calcium Binding Protein A7; D009418:S100 Proteins / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013211:Staphylococcus aureus / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D012333:RNA, Messenger; D000075023:S100 Calcium Binding Protein A7; D009418:S100 Proteins; C089242:S100A7 protein, human