Protease nexin-1 inhibits plasminogen activation-induced apoptosis of adherent cells.
Degradation of adhesive glycoproteins by plasmin is implicated in cell migration. In this study, we further explored the role of plasminogen activation in cell adhesion and survival and show that uncontrolled plasminogen activation at the cell surface may induce cell detachment and apoptosis. We hypothesized that this process could be prevented in adherent cells by expression of protease nexin-1, a potent serpin able to inhibit thrombin, plasmin, and plasminogen activators. Using two- and three-dimensional culture systems, we demonstrate that Chinese hamster ovary fibroblasts constitutively express tissue-type plasminogen activator and efficiently activate exogenously added plasminogen in a specific and saturable manner (K(m) = 46 nm). The formation of plasmin results in proteolysis of fibronectin and laminin, which is followed by cell detachment and apoptosis. Protease nexin-1 expressed by transfected cells significantly inhibited the activity of plasmin and tissue-type plasminogen activator via the formation of inhibitory complexes and prevented cell detachment and apoptosis. In conclusion, protease nexin-1 may be an important anti-apoptotic factor for adherent cells. This cell model could be a useful tool to evaluate therapeutic agents such as serpins in vascular pathologies involving pericellular protease-protease inhibitor imbalance.
Rossignol
Patrick
P
INSERM U460, Centre Hospitalier Universitaire Bichat-Claude Bernard, Paris 18, France.
Ho-Tin-Noé
Benoît
B
Vranckx
Roger
R
Bouton
Marie-Christine
MC
Meilhac
Olivier
O
Lijnen
H Roger
HR
Guillin
Marie-Claude
MC
Michel
Jean-Baptiste
JB
Anglés-Cano
Eduardo
E
D016564:Amyloid beta-Protein Precursor; D000818:Animals; D023102:Anoikis; D017209:Apoptosis; D016466:CHO Cells; D002352:Carrier Proteins / Q000502:physiology*; D020169:Caspases / Q000378:metabolism; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D002455:Cell Division; D002470:Cell Survival; D002474:Cell-Free System; D006224:Cricetinae; D004247:DNA / Q000737:chemistry; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000737:chemistry; D006801:Humans; D015151:Immunoblotting; D020287:In Situ Nick-End Labeling; D007700:Kinetics; D007797:Laminin / Q000737:chemistry; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D010958:Plasminogen / Q000737:chemistry / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D058258:Serpin E2; D013997:Time Factors; D014162:Transfection; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
D016564:Amyloid beta-Protein Precursor; D002352:Carrier Proteins; D005353:Fibronectins; D007797:Laminin; D017395:Plasminogen Activator Inhibitor 1; D058255:Protease Nexins; D011956:Receptors, Cell Surface; C545486:SERPINE2 protein, human; D058258:Serpin E2; D010958:Plasminogen; D004247:DNA; D014568:Urokinase-Type Plasminogen Activator; D020169:Caspases; D020780:Matrix Metalloproteinase 9