Urokinase induces matrix metalloproteinase-9/gelatinase B expression in THP-1 monocytes via ERK1/2 and cytosolic phospholipase A2 activation and eicosanoid production.
OBJECTIVE
Urokinase-type plasminogen activator (uPA) regulates cell migration and invasion by pericellular proteolysis and signal transduction events. We characterized the mechanisms by which uPA regulates matrix metalloproteinase-9 (MMP9) function in THP-1 monocytes.


RESULTS
In THP-1 monocytes, MMP9 production induced by urokinase was completely inhibited by the ERK1/2 inhibitor, PD98059, but not by the p38 mitogen-activated protein kinase inhibitor, SB202190. A dominant negative MEK1 adenovirus also blocked MMP9 expression. The effect of urokinase was completely suppressed by genistein and by herbimycin A indicating that tyrosine kinase(s) are required for MMP9 production. Bisindolylmaleimide, a protein kinase C (PKC) inhibitor, did not decrease MMP9 expression suggesting that PKC activation is not required. Key roles for cytosolic phospholipase A2 (PLA2) and eicosanoid production were shown by complete inhibition with methyl arachidonyl fluorophosphonate (an inhibitor of cytosolic PLA2), and indomethacin (a cyclooxygenase inhibitor), with no effect of monoalide, a secretory PLA2 inhibitor. uPA stimulated phosphorylation of cytosolic PLA2.


CONCLUSIONS
Induction of MMP9 by uPA in THP-1 monocytes is via a pathway involving MEK1-ERK1/2-mediated activation of cytosolic PLA2 and eicosanoid generation. These data suggest important roles for eicosanoids in monocyte migration induced by uPA and MMP9.
Menshikov
Mikhail
M
Institute of Experimental Cardiology, Cardiology Research Center, Moscow, Russia. myumensh@cardio.ru
Torosyan
Narine
N
Elizarova
Eugenia
E
Plakida
Karina
K
Vorotnikov
Alexander
A
Parfyonova
Yelena
Y
Stepanova
Victoria
V
Bobik
Alex
A
Berk
Bradford
B
Tkachuk
Vsevolod
V
D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D015777:Eicosanoids / Q000096:biosynthesis*; D004789:Enzyme Activation; D006801:Humans; D007700:Kinetics; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D014158:Transcription, Genetic; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D015777:Eicosanoids; D012333:RNA, Messenger; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D014568:Urokinase-Type Plasminogen Activator; D020780:Matrix Metalloproteinase 9