Fibrinolysis in LPS-induced chronic airway disease.
To examine the role of the fibrinolytic system in LPS-induced airway disease, we compared the effect of a chronic LPS challenge in plasminogen activator inhibitor-deficient (C57BL/6JPAI-1-/-) mice and wild-type (WT) C57BL/6J mice. Physiological and biological assessments were performed, immediately after, and 4 wk after an 8-wk exposure to LPS or saline. Immediately after the LPS exposure, WT mice had increased estimates of airway reactivity to methacholine compared with C57BL/6JPAI-1-/- mice; however, airway inflammation was similar in both LPS-exposed groups. Significant increases in both active transforming growth factor (TGF)-beta1 and active matrix metalloproteinase (MMP)-9 was detected after LPS exposure in WT but not C57BL/6JPAI-1-/- mice. C57BL/6JPAI-1-/- mice showed significantly less TGF-beta1 in the lavage and higher MMP-9 in the lung tissue than WT mice at the end of exposure and 4 wk later. After LPS exposure, both WT and C57BL/6JPAI-1-/- mice had substantial expansion of the subepithelial area of the medium [diameter (d) = 90-129 microm]- and large (d > 129 microm)-size airways when compared with saline-exposed mice. Subepithelial fibrin deposition was prevalent in WT mice but diminished in C57BL/6JPAI-1-/-. PAI-1 expression by nonciliated bronchial epithelial cells was enhanced in LPS-exposed WT mice compared with the saline-exposed group. Four weeks after LPS inhalation, airway hyperreactivity and the expansion of the subepithelial area in the medium and large airways persisted in WT but not C57BL/6JPAI-1-/- mice. We conclude that an active fibrinolytic system can substantially alter the development and resolution of the postinflammatory airway remodeling observed after chronic LPS inhalation.
Savov
Jordan D
JD
Duke Univ. Medical Center, P. O. Box 2629, Durham, NC 27710, USA. jsavov@duke.edu
Brass
David M
DM
Berman
Katherine G
KG
McElvania
Erin
E
Schwartz
David A
DA
D000280:Administration, Inhalation; D000818:Animals; D002908:Chronic Disease; D005342:Fibrinolysis; D007150:Immunohistochemistry; D008070:Lipopolysaccharides / Q000008:administration & dosage*; D008168:Lung / Q000378:metabolism / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017395:Plasminogen Activator Inhibitor 1 / Q000172:deficiency / Q000378:metabolism; D011014:Pneumonia / Q000097:blood* / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D007507:Therapeutic Irrigation; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1
D008070:Lipopolysaccharides; D017395:Plasminogen Activator Inhibitor 1; C508961:Tgfb1 protein, mouse; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D020780:Matrix Metalloproteinase 9