COX-2 is widely expressed in metaplastic epithelium in pulmonary fibrous disorders.
Idiopathic usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) and asbestosis represent progressive and often fatal pulmonary fibrous disorders, whereas cryptogenic organizing pneumonia (COP), desquamative interstitial pneumonia (DIP), and respiratory bronchiolitis-interstitial lung disease (RB-ILD) usually are reversible or nonprogressive conditions. Prostaglandin E2 (PGE2) inhibits fibroblast proliferation and myofibroblast transition, its production depending on cyclooxygenase-2 (COX-2). In patients with UIP/IPF, levels of PGE2 and COX-2 are reduced in fibroblasts, and levels of PGE2 in bronchioalveolar lavage fluid may be lowered. We analyzed the immunohistochemical expression of COX-2 in UIP/IPF, asbestosis, COP, DIP, and RB-ILD. Our results show that the metaplastic epithelium in UIP/IPF, asbestosis, and COP is widely COX-2+, whereas COX-2 positivity is scant in DIP and RB-ILD. The mesenchymal cells remained negative. Our results suggest that irrespective of the underlying disease, lung injury that causes extensive fibrosis induces wide expression of COX-2 in the regenerating metaplastic epithelium.
Lappi-Blanco
Elisa
E
Department of Pathology, Oulu, University, Oulu, Finland.
Kaarteenaho-Wiik
Riitta
R
Maasilta
Paula K
PK
Anttila
Sisko
S
Pääkkö
Paavo
P
Wolff
Henrik J
HJ
D001195:Asbestosis / Q000201:enzymology / Q000473:pathology; D001988:Bronchiolitis / Q000201:enzymology / Q000473:pathology; D018549:Cryptogenic Organizing Pneumonia / Q000201:enzymology / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004848:Epithelium / Q000201:enzymology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017563:Lung Diseases, Interstitial / Q000201:enzymology / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D008679:Metaplasia; D011658:Pulmonary Fibrosis / Q000201:enzymology / Q000473:pathology*
D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human