title: Matrix metalloproteinase-9 (92 kDa gelatinase/type IV collagenase) from U937 monoblastoid cells: correlation with cellular invasion.
abstract: The role of matrix metalloproteinase-9 (MMP-9, 92 kDa gelatinase/type IV collagenase) in invasion of mononuclear phagocytes was studied with U937 monoblastoid cells. 12-o-tetradecanoyl 13-phorbol acetate (TPA) differentiated them to macrophage-like cells with induction of MMP-9, and tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha) stimulated the production of MMP-9 by TPA-treated cells. TNF alpha also induced the production of MMP-9 by TPA-untreated U937 cells without morphological differentiation. Other agents including dimethyl sulfoxide (DMSO), all-trans-retinoic acid (all-trans-RA), platelet-derived growth factor and 3';5'-cyclic monophosphate had no effects on MMP-9 production by TPA-treated or -untreated cells, but all-trans-RA and DMSO did have a morphological effect on the differentiation of the cells. These data suggest that MMP-9 production by U937 cells is regulated by a mechanism independent of the differentiation to macrophage-like cells. MMP-9 was purified to homogeneity as an inactive zymogen with M(r) 92,000 (proMMP-9) from TPA-differentiated U937 cells treated with TNF alpha. ProMMP-9 was activated by p-aminophenylmercuric acetate (APMA) generating an active species of M(r) 67,000. Trypsin and cathepsin G also attained activation of the zymogen to its full activity obtained by APMA activation, but plasmin, leukocyte elastase, thrombin and plasma kallikrein had no ability to activate it. APMA-activated MMP-9 degraded type I gelatin readily and cleaved native collagen types III, IV and V. Invasion assays using reconstituted basement membrane coupled with a type IV collagenolysis assay showed good correlations between invasiveness, type IV collagenolysis and proMMP-9 production. Invasion was significantly inhibited by EDTA, alpha 2-macroglobulin and tissue inhibitor of metalloproteinases-1, but not by inhibitors of cathepsin G and leukocyte elastase. These data suggest that MMP-9 plays an important role in the invasion of mononuclear phagocytes through basement membranes.
authors.affiliation: Department of Pathology, School of Medicine, Kanazawa University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: I
authors.initials: I
authors.lastname: Nakanishi
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
mesh_terms: D001485:Basement Membrane / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D017364:Collagenases / Q000096:biosynthesis / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D004792:Enzyme Precursors / Q000096:biosynthesis / Q000302:isolation & purification; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology*; D020780:Matrix Metalloproteinase 9; D009000:Monocytes / Q000187:drug effects / Q000201:enzymology*; D012697:Serine Endopeptidases / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate; D014407:Tumor Cells, Cultured
chemical_list: D004792:Enzyme Precursors; D012697:Serine Endopeptidases; D017364:Collagenases; D020780:Matrix Metalloproteinase 9; D013755:Tetradecanoylphorbol Acetate