Collagen dissolution by keratinocytes requires cell surface plasminogen activation and matrix metalloproteinase activity.
Matrix metalloproteinase-14 is required for degradation of fibrillar collagen by mesenchymal cells. Here we show that keratinocytes use an alternative plasminogen and matrix metalloproteinase-13-dependent pathway for dissolution of collagen fibrils. Primary keratinocytes displayed an absolute requirement for serum to dissolve collagen. Dissolution of collagen was abolished in plasminogen-depleted serum and could be restored by the exogenous addition of plasminogen. Both plasminogen activator inhibitor-1 and tissue inhibitor of metalloproteinase blocked collagen dissolution, demonstrating the requirement of both plasminogen activation and matrix metalloproteinase activity for degradation. Cell surface plasmin activity was critical for the degradation process as aprotinin, but not alpha(2)-antiplasmin, prevented collagen dissolution. Keratinocytes with single deficiencies in either urokinase or tissue plasminogen activator retained the ability to dissolve collagen. However, collagen fibril dissolution was abolished in keratinocytes with a combined deficiency in both urokinase and tissue plasminogen activator. Combined, but not single, urokinase and tissue plasminogen activator deficiency also completely blocked the activation of the fibrillar collagenase, matrix metalloproteinase-13, by keratinocytes. The activation of matrix metalloproteinase-13 in normal keratinocytes was prevented by plasminogen activator inhibitor-1 and aprotinin but not by tissue inhibitor of metalloproteinase-1 and -2, suggesting that plasmin activates matrix metalloproteinase-13 directly. We propose that plasminogen activation facilitates keratinocyte-mediated collagen breakdown via the direct activation of matrix metalloproteinase-13 and possibly other fibrillar collagenases.
Matrix Metalloproteinase Unit, NIDCR, National Institutes of Health, Bethesda, Maryland 20892, USA.
Sarah
S
Netzel-Arnett
David J
DJ
Mitola
Susan S
SS
Yamada
Kali
K
Chrysovergis
Kenn
K
Holmbeck
Henning
H
Birkedal-Hansen
Thomas H
TH
Bugge
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D017364:Collagenases / Q000378:metabolism*; D016895:Culture Media, Serum-Free; D004789:Enzyme Activation; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D018390:Gene Targeting; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D008297:Male; D053509:Matrix Metalloproteinase 13; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010958:Plasminogen / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D010960:Plasminogen Activators / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics; D055293:Receptors, Urokinase Plasminogen Activator; D015842:Serine Proteinase Inhibitors / Q000378:metabolism; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000235:genetics; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics
D016895:Culture Media, Serum-Free; C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; C524899:Plaur protein, mouse; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D015842:Serine Proteinase Inhibitors; D019714:Tissue Inhibitor of Metalloproteinases; D010958:Plasminogen; D003094:Collagen; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator; D017364:Collagenases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C507081:Mmp13 protein, mouse