title: Immunohistochemical study of metalloproteinases and their tissue inhibitors in the lungs of patients with diffuse alveolar damage and idiopathic pulmonary fibrosis.
abstract: Immunohistochemical and confocal microscopic studies of the localization of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and type IV collagen were made in lung tissues from patients with normal pulmonary histology (n = 3), diffuse alveolar damage (n = 14), and idiopathic pulmonary fibrosis (n = 12). Pretreatment with pepsin revealed otherwise undetectable MMP- and TIMP-immunoreactive sites. In normal lung, MMP-2, MMP-9, TIMP-1, and TIMP-2 were localized in ciliated cells, endothelial cells, pneumocytes, macrophages, and smooth muscle cells; fibroblasts showed a strong reaction only for MMP-2. Only TIMP-2 showed co-localization with type IV collagen. Myofibroblasts and epithelial cells expressed increased reactivity for MMPs and TIMPs in both disorders. The reactivities for MMPs and TIMPs were stronger in diffuse alveolar damage. MMP-2 showed focal co-localization in capillary endothelial and disrupted epithelial basement membranes, suggesting activation of collagenolysis. A protective effect against this lysis was suggested by the extensive co-localization of TIMP-2 with type IV collagen and fibrillar collagens. Alveolar buds showed increased reactivity for MMPs and TIMPs in their lining epithelial cells, myofibroblasts, and their basement membranes; however, their matrices were mostly unreactive. These findings emphasize the complexity of the roles of MMPs and TIMPs in collagen turnover in diffuse alvcolar damage and idiopathic pulmonary fibrosis.
authors.affiliation: Pathology Section, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1518, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: W G
authors.initials: WG
authors.lastname: Stetler-Stevenson
authors.forename: M V
authors.initials: MV
authors.lastname: Fleming
authors.forename: N
authors.initials: N
authors.lastname: Fishback
authors.forename: M N
authors.initials: MN
authors.lastname: Koss
authors.forename: L A
authors.initials: LA
authors.lastname: Liotta
authors.forename: V J
authors.initials: VJ
authors.lastname: Ferrans
authors.forename: W D
authors.initials: WD
authors.lastname: Travis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D003094:Collagen / Q000032:analysis*; D017364:Collagenases / Q000032:analysis*; D005260:Female; D018093:Gelatinases / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D008666:Metalloendopeptidases / Q000032:analysis*; D018613:Microscopy, Confocal; D008875:Middle Aged; D011506:Proteins / Q000032:analysis*; D011650:Pulmonary Alveoli / Q000737:chemistry / Q000473:pathology*; D011658:Pulmonary Fibrosis / Q000473:pathology*; D019716:Tissue Inhibitor of Metalloproteinase-2; D019714:Tissue Inhibitor of Metalloproteinases
chemical_list: D015415:Biomarkers; D006023:Glycoproteins; D011506:Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D019716:Tissue Inhibitor of Metalloproteinase-2; D003094:Collagen; D017364:Collagenases; D018093:Gelatinases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9