title: A 96-kDa gelatinase induced by TNF-alpha contributes to increased microvascular endothelial permeability.
abstract: Tumor necrosis factor-alpha (TNF-alpha) may increase vascular endothelial permeability through alteration of the extracellular matrix (ECM). Incubation of bovine pulmonary microvascular endothelial (BPMVE) cells grown to confluence on microporous filters with 10(4) U/ml TNF-alpha for 24 h increased monolayer permeability to 125I-labeled albumin two- to threefold. TNF-alpha treatment also induced expression of a 96-kDa gelatinolytic metalloproteinase that was present in the medium and bound to the ECM. The induced 96-kDa metalloproteinase was purified from conditioned medium and found to cleave fibronectin, laminin, types IV and V collagens, and gelatins from types I and III collagens, suggesting identity as a type IV collagenase-gelatinase. Incubation of BPMVE cells with the 96-kDa gelatinase increased monolayer permeability, an effect prevented by inclusion of either tissue inhibitor of metalloproteinase (TIMP) or 1,10-phenanthroline. When BPMVE cells were incubated with the 96-kDa gelatinase or 10(4) U/ml TNF-alpha and then stripped from the filters, the remaining ECM displayed increased permeability to 125I-albumin compared with matrix from untreated BPMVE. The ECM extracts from both TNF-alpha- and enzyme-treated cells were found to contain less fibronectin, whereas their total protein contents were similar to those of untreated controls. These results suggest that the 96-kDa metalloproteinase induced by TNF-alpha contributes to increased vascular endothelial permeability through the degradation of specific extracellular matrix components.
authors.affiliation: Department of Physiology, Albany Medical College of Union University, New York 12208.
authors.forename: C A
authors.initials: CA
authors.lastname: Partridge
authors.forename: J J
authors.initials: JJ
authors.lastname: Jeffrey
authors.forename: A B
authors.initials: AB
authors.lastname: Malik
mesh_terms: D000818:Animals; D002364:Caseins / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D005353:Fibronectins / Q000378:metabolism; D018093:Gelatinases / Q000096:biosynthesis* / Q000302:isolation & purification; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D061965:Matrix Metalloproteinase Inhibitors; D008833:Microcirculation; D008970:Molecular Weight; D010618:Phenanthrolines / Q000494:pharmacology; D011652:Pulmonary Circulation; D013379:Substrate Specificity; D019714:Tissue Inhibitor of Metalloproteinases; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D002364:Caseins; D005353:Fibronectins; D006023:Glycoproteins; D061965:Matrix Metalloproteinase Inhibitors; D010618:Phenanthrolines; D019714:Tissue Inhibitor of Metalloproteinases; D014409:Tumor Necrosis Factor-alpha; D018093:Gelatinases; C025205:1,10-phenanthroline