Activation of pro-urokinase and plasminogen on human sarcoma cells: a proteolytic system with surface-bound reactants
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Activation of pro-urokinase and plasminogen on human sarcoma cells : a proteolytic system with surface-bound reactants. / Stephens, R. W.; Pöllänen, J.; Tapiovaara, Hannele; Leung, Ken C-F; Sim, P S; Salonen, Eeva-Marjatta; Rønne, E; Behrendt, N; Danø, K; Vaheri, Antti.
I: Journal of Cell Biology, Bind 108, Nr. 5, 05.1989, s. 1987-95.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Activation of pro-urokinase and plasminogen on human sarcoma cells
T2 - a proteolytic system with surface-bound reactants
AU - Stephens, R. W.
AU - Pöllänen, J.
AU - Tapiovaara,, Hannele
AU - Leung, Ken C-F
AU - Sim, P S
AU - Salonen,, Eeva-Marjatta
AU - Rønne, E
AU - Behrendt, N
AU - Danø, K
AU - Vaheri,, Antti
PY - 1989/5
Y1 - 1989/5
N2 - Human HT-1080 fibrosarcoma cells produce urokinase-type plasminogen activator (u-PA) and type 1 plasminogen activator inhibitor (PAI-1). We found that after incubation of monolayer cultures with purified native human plasminogen in serum-containing medium, bound plasmin activity could be eluted from the cells with tranexamic acid, an analogue of lysine. The bound plasmin was the result of plasminogen activation on the cell surface; plasmin activity was not taken up onto cells after deliberate addition of plasmin to the serum-containing medium. The cell surface plasmin formation was inhibited by an anticatalytic monoclonal antibody to u-PA, indicating that this enzyme was responsible for the activation. Preincubation of the cells with diisopropyl fluorophosphate-inhibited u-PA led to a decrease in surface-bound plasmin, indicating that a large part, if not all, of the cell surface plasminogen activation was catalyzed by surface-bound u-PA. In the absence of plasminogen, most of the cell surface u-PA was present in its single-chain proenzyme form, while addition of plasminogen led to formation of cell-bound two-chain u-PA. The latter reaction was catalyzed by cell-bound plasmin. Cell-bound u-PA was accessible to inhibition by endogenous PAI-1 and by added PAI-2, while the cell-bound plasmin was inaccessible to serum inhibitors, but accessible to added aprotinin and an anticatalytic monoclonal antibody. A model for cell surface plasminogen activation is proposed in which plasminogen binding to cells from serum medium is followed by plasminogen activation by trace amounts of bound active u-PA, to form bound plasmin, which in turn serves to produce more active u-PA from bound pro-u-PA. This exponential process is subject to regulation by endogenous PAI-1 and limited to the pericellular space.
AB - Human HT-1080 fibrosarcoma cells produce urokinase-type plasminogen activator (u-PA) and type 1 plasminogen activator inhibitor (PAI-1). We found that after incubation of monolayer cultures with purified native human plasminogen in serum-containing medium, bound plasmin activity could be eluted from the cells with tranexamic acid, an analogue of lysine. The bound plasmin was the result of plasminogen activation on the cell surface; plasmin activity was not taken up onto cells after deliberate addition of plasmin to the serum-containing medium. The cell surface plasmin formation was inhibited by an anticatalytic monoclonal antibody to u-PA, indicating that this enzyme was responsible for the activation. Preincubation of the cells with diisopropyl fluorophosphate-inhibited u-PA led to a decrease in surface-bound plasmin, indicating that a large part, if not all, of the cell surface plasminogen activation was catalyzed by surface-bound u-PA. In the absence of plasminogen, most of the cell surface u-PA was present in its single-chain proenzyme form, while addition of plasminogen led to formation of cell-bound two-chain u-PA. The latter reaction was catalyzed by cell-bound plasmin. Cell-bound u-PA was accessible to inhibition by endogenous PAI-1 and by added PAI-2, while the cell-bound plasmin was inaccessible to serum inhibitors, but accessible to added aprotinin and an anticatalytic monoclonal antibody. A model for cell surface plasminogen activation is proposed in which plasminogen binding to cells from serum medium is followed by plasminogen activation by trace amounts of bound active u-PA, to form bound plasmin, which in turn serves to produce more active u-PA from bound pro-u-PA. This exponential process is subject to regulation by endogenous PAI-1 and limited to the pericellular space.
KW - Cell Line
KW - Cell Membrane
KW - Culture Media
KW - Enzyme Activation
KW - Fibrinolysin
KW - Fibrosarcoma
KW - Humans
KW - Kinetics
KW - Molecular Weight
KW - Peptide Hydrolases
KW - Plasminogen
KW - Plasminogen Activators
KW - Protein Binding
KW - Tumor Cells, Cultured
KW - Urokinase-Type Plasminogen Activator
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
M3 - Journal article
C2 - 2523891
VL - 108
SP - 1987
EP - 1995
JO - Journal of Cell Biology
JF - Journal of Cell Biology
SN - 0021-9525
IS - 5
ER -
ID: 180824356