title: Matrix metalloproteinase-9 promotes neutrophil migration and alveolar capillary leakage in pancreatitis-associated lung injury in the rat.
abstract: OBJECTIVE
  In pancreatitis-associated lung injury, neutrophils (PMN) access the lung by migration through endothelial basement membranes. We hypothesize that degeneration of the basement membrane by specific PMN-produced matrix metalloproteinases (MMPs) may facilitate this process.
  
  
  METHODS
  Mild or severe pancreatitis was induced in rats and the consequent pulmonary injury characterized. MMP-2 and MMP-9 activity in supernatant of PMN cultures and homogenates of lungs were assessed by zymography and Western blot. Congruence of PMN and MMP expression in lung tissue was evaluated by neutrophil depletion and fluorescent immunohistochemistry (IHC). The contribution of MMPs to PMN transmigration and lung injury was tested with the MMP inhibitor batimastat (BB-94) in vitro (PMN transmigration across matrigel chambers) and in vivo (myeloperoxidase activity and Evans blue in broncho-alveolar lavage fluid).
  
  
  RESULTS
  MMP-9 was highly expressed in lungs and supernatant of neutrophil cultures in severe pancreatitis, and, to a lesser degree, in mild pancreatitis. Lung IHC showed colocalization of MMP-9 and PMN. PMN depletion simultaneously reduced neutrophil infiltration and MMP-9 levels in lung tissue. Trypsin, interleukin 1 beta, and tumor necrosis factor (TNF)-alpha all potently stimulated MMP-9 release from PMN. BB-94 significantly reduced TNF-alpha-induced PMN transmigration across matrigel and ameliorated transendothelial PMN migration and protein leak in severe pancreatitis.
  
  
  CONCLUSIONS
  MMP-9 secretion by PMN can be stimulated by trypsin and proinflammatory cytokines and increases in pancreatitis in proportion to its severity. MMP inhibition reduces PMN transmigration and reduces resultant alveolar-capillary leakage. These findings suggest an important role for MMP-9 from PMN in the pathogenesis of pancreatitis-associated lung injury.
authors.affiliation: Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Keck
authors.forename: James H
authors.initials: JH
authors.lastname: Balcom
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-del Castillo
authors.forename: Bozena A
authors.initials: BA
authors.lastname: Antoniu
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
mesh_terms: D000208:Acute Disease; D000818:Animals; D001485:Basement Membrane / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D002199:Capillary Permeability / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D002478:Cells, Cultured; D004396:Coloring Agents / Q000493:pharmacokinetics; D005070:Evans Blue / Q000493:pharmacokinetics; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D008171:Lung Diseases / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D010195:Pancreatitis / Q000150:complications / Q000276:immunology* / Q000503:physiopathology; D009195:Peroxidase / Q000378:metabolism; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000098:blood supply* / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013876:Thiophenes / Q000494:pharmacology; D014357:Trypsin / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D004396:Coloring Agents; D007375:Interleukin-1; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; D013876:Thiophenes; D014409:Tumor Necrosis Factor-alpha; D005070:Evans Blue; D010649:Phenylalanine; C080985:batimastat; D009195:Peroxidase; D014357:Trypsin; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9