title: Differential expression of C-reactive protein and serum amyloid A in different cell types in the lung tissue of chronic obstructive pulmonary disease patients.
abstract: BACKGROUND
  Chronic systemic inflammatory syndrome has been implicated in the pathobiology of extrapulmonary manifestations of chronic obstructive pulmonary disease (COPD). We aimed to investigate which cell types within lung tissue are responsible for expressing major acute-phase reactants in COPD patients and disease-free ("resistant") smokers.
  
  
  METHODS
  An observational case-control study was performed to investigate three different cell types in surgical lung samples of COPD patients and resistant smokers via expression of the C-reactive protein (CRP) and serum amyloid A (SAA1, SAA2 and SAA4) genes. Epithelial cells, macrophages and fibroblasts from the lung parenchyma were separated by magnetic microbeads (CD326, CD14 and anti-fibroblast), and gene expression was evaluated by RT-PCR.
  
  
  RESULTS
  The sample consisted of 74 subjects, including 40 COPD patients and 34 smokers without disease. All three cell types were capable of synthesizing these biomarkers to some extent. In fibroblasts, gene expression analysis of the studied biomarkers demonstrated increased SAA2 and decreased SAA1 in patients with COPD. In epithelial cells, there was a marked increase in CRP, which was not observed in fibroblasts or macrophages. In macrophages, however, gene expression of these markers was decreased in COPD patients compared to controls.
  
  
  CONCLUSIONS
  These results provide novel information regarding the gene expression of CRP and SAA in different cell types in the lung parenchyma. This study revealed differences in the expression of these markers according to cell type and disease status and contributes to the identification of cell types that are responsible for the secretion of these molecules.
authors.affiliation: Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Hospital Virgen del Rocío, Sevilla, Spain. ccalero-ibis@us.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Calero
authors.forename: Elena
authors.initials: E
authors.lastname: Arellano
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Lopez-Villalobos
authors.forename: Verónica
authors.initials: V
authors.lastname: Sánchez-López
authors.forename: Nicolás
authors.initials: N
authors.lastname: Moreno-Mata
authors.forename: José Luis
authors.initials: JL
authors.lastname: López-Campos
mesh_terms: D000328:Adult; D002097:C-Reactive Protein / Q000032:analysis / Q000235:genetics*; D016022:Case-Control Studies; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D016015:Logistic Models; D008264:Macrophages / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics* / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012016:Reference Values; D012129:Respiratory Function Tests; D000685:Serum Amyloid A Protein / Q000032:analysis / Q000235:genetics*; D012720:Severity of Illness Index; D012907:Smoking; D018709:Statistics, Nonparametric
chemical_list: D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein