title: In vivo collagenase-2 (MMP-8) expression by human bronchial epithelial cells and monocytes/macrophages in bronchiectasis.
abstract: The purpose of this study was to determine whether other cellular sources than neutrophils can express matrix metalloproteinase (MMP)-8 protein and mRNA in bronchiectatic (BE) lung. The molecular forms of MMP-8 in the BE bronchoalveolar lavage fluid (BALF) and healthy control BALF were analysed by western immunoblotting. MMP-8 expression was demonstrated by immunohistochemistry and in situ hybridization in BE lung tissue and by immunohistochemistry in control lung tissue. In the BE BALF, different MMP-8 species were detected: 70-80 kD MMP-8 apparently of polymorphonuclear leukocyte (PMN) origin and also 40-60 kD MMP-8 from non-PMN cellular sources, such as bronchial epithelial cells, glandular cells or monocytes/macrophages. Both of these MMP-8 species were elevated and converted to a significant extent to activated forms in BE BALF compared with healthy control BALF. The levels of high molecular weight (>80 kD) MMP-8 complexes, evidently representing MMP-8 trapped by endogenous MMP inhibitors and/or MMP-8 dimers, were significantly elevated in BE BALF compared with healthy control BALF. In BE lung tissue, the MMP-8 protein and mRNA expression was found in bronchial ciliated epithelial cells, glandular cells, neutrophils, and monocytes/macrophages infiltrating the bronchial epithelial area. Minimal MMP-8 expression was observed in neutrophils, monocytes/macrophages, and epithelial cells in control lung tissues. In this study, new potential cellular sources have been demonstrated for MMP-8 in the inflamed lung. MMP-8 from multiple cellular sources, including inflamed lung epithelium, was activated to a significant extent in the BE BALF, indicating a major role for MMP-8 in the destruction of lung and bronchial tissues.
authors.affiliation: Department of Pulmonology, University of Tartu, Tartu, Estonia. tsorsa@hammas.helsinki.fi
authors.forename: K
authors.initials: K
authors.lastname: Prikk
authors.forename: P
authors.initials: P
authors.lastname: Maisi
authors.forename: E
authors.initials: E
authors.lastname: Pirilä
authors.forename: R
authors.initials: R
authors.lastname: Sepper
authors.forename: T
authors.initials: T
authors.lastname: Salo
authors.forename: J
authors.initials: J
authors.lastname: Wahlgren
authors.forename: T
authors.initials: T
authors.lastname: Sorsa
mesh_terms: D015153:Blotting, Western; D001987:Bronchiectasis / Q000201:enzymology*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D016022:Case-Control Studies; D004848:Epithelium / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008264:Macrophages / Q000201:enzymology*; D020784:Matrix Metalloproteinase 8 / Q000032:analysis* / Q000235:genetics; D009000:Monocytes / Q000201:enzymology; D009504:Neutrophils / Q000201:enzymology; D012333:RNA, Messenger / Q000032:analysis; D018709:Statistics, Nonparametric
chemical_list: D012333:RNA, Messenger; D020784:Matrix Metalloproteinase 8