Plasmin activates pro-matrix metalloproteinase-2 with a membrane-type 1 matrix metalloproteinase-dependent mechanism.
Membrane-type 1 matrix metalloproteinase (MT1-MMP) has been implicated as a physiological activator of progelatinase A (MMP-2). We previously reported that plasmin treatment of cells results in proMMP-2 activation and increased type IV collagen degradation. Here, we analyzed the role of MT1-MMP in plasmin activation of MMP-2 using HT-1080 cells transfected with MT1-MMP sense or antisense cDNA. Control, vector-transfected cells that expressed endogenous MT1-MMP, and antisense cDNA transfectants with very low levels of MT1-MMP did not activate proMMP-2. Conversely, cells transfected with sense MT1-MMP cDNA expressed high MT1-MMP levels and processed proMMP-2 to 68/66-kDa intermediate activation products. Control cells and MT1-MMP transfectants had much higher levels of cell-associated MMP-2 than antisense cDNA transfectants. Addition of plasmin(ogen) to control or MT1-MMP-transfected cells generated active, 62-kDa MMP-2, but was ineffective with antisense cDNA transfectants. The effect of plasmin(ogen) was prevented by inhibitors of plasmin, but not by metalloproteinase inhibitors, implicating plasmin as a mechanism for proMMP-2 activation independent of the activity of MT1-MMP or other MMPs. Plasmin-mediated activation of proMMP-2 did not result from processing of proMT1-MMP and did not correlate with alpha(v)beta(3) integrin or TIMP-2 levels. Thus, plasmin can activate proMMP-2 only in the presence of MT1-MMP; however, this process does not require the catalytic activity of MT1-MMP.
Monea
Sara
S
Department of Surgery, S.A. Localio Laboratory for General Surgery Research, New York, New York, USA.
Lehti
Kaisa
K
Keski-Oja
Jorma
J
Mignatti
Paolo
P
D018076:DNA, Complementary; D004789:Enzyme Activation; D005341:Fibrinolysin / Q000378:metabolism*; D018093:Gelatinases / Q000378:metabolism; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism*; D019030:Receptors, Vitronectin / Q000378:metabolism*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D019030:Receptors, Vitronectin; D019716:Tissue Inhibitor of Metalloproteinase-2; D005341:Fibrinolysin; D018093:Gelatinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2