Transgenic Mice Overexpressing Urokinase-Type Plasminogen Activator in the Brain Exhibit Reduced Food Consumption, Body Weight and Size, and Increased Longevity

Abstract Targeting of plasminogen activators to the fibrin component of a thrombus with the use of monoclonal antibodies (MA) directed against human fibrin may enhance their thrombolytic potency and fibrin- specificity. The thrombolytic and pharmacokinetic properties of rscu- PA/MA-FU1–74, an immunoconjugate of recombinant single-chain urokinase- type plasminogen activator (rscu-PA) and a bispecific MA directed against u-PA and against the beta-chain of human fibrin (MA-FU1–74), were investigated in baboons with a [125I]fibrin-labeled autologous blood clot in the femoral vein. Continuous intravenous infusion of rscu- PA/MA-FU1–74 (1:1.2 molar ratio) over 2 hours showed a fivefold increased thrombolytic potency (lysis per unit dose) over that of unconjugated rscu-PA, as evidenced both by a higher maximal rate of lysis (380% +/- 68% v 78% +/- 25% lysis per mg u-PA equivalent of compound administered per kg body weight, P less than .001), and by a lower dose at which the maximal rate of lysis occurs (0.19 +/- 0.03 v 0.82 +/- 0.10 mg compound per kg body weight, P less than .001). The specific thrombolytic activity (percent lysis per unit steady-state plasma u-PA antigen level) was lower for rscu-PA/MA-FU1–74 than for rscu-PA, as shown by both a lower maximal rate of lysis (60% +/- 13% v 220% +/- 22% lysis per microgram/mL u-PA antigen level in plasma, P less than .001) and a higher plasma antigen level at which maximal lysis is achieved (1.2 +/- 0.17 v 0.20 +/- 0.01 microgram/mL, P less than .001). The thrombolytic potency of rscu-PA/MA-UK1–3, an immunoconjugate of rscu-PA with the parental anti-u-PA antibody was similar to that of unconjugated rscu-PA. Clot lysis was achieved without systemic fibrinogen or alpha 2-antiplasmin consumption, and with a minor transient prolongation of the bleeding time. After the end of the infusions, u-PA-related antigen disappeared from plasma in a biphasic manner, with an initial half-life of 3.3 +/- 0.4 minutes for rscu-PA, 13 +/- 1 minutes for rscu-PA/MA-FU1–74, and 13 +/- 1 minutes for rscu-PA/MA-UK1–3, with corresponding plasma clearances of 340 +/- 28, 10 +/- 1, and 37 +/- 4 mL/min, respectively (mean +/- SEM). rscu- PA/MA-FU1–74 has a fivefold higher thrombolytic potency than unconjugated rscu-PA, as a result both of fibrin targeting by the specific idiotype of the antibody and of a slower plasma clearance.

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Production of active human urokinase-type plasminogen activator in the milk of transgenic mice

Pharmacological Research ◽

10.1016/s1043-6618(09)80115-1 ◽

1990 ◽

Vol 22 ◽

pp. 65

Author(s):

Anna Brandazza ◽

Monica Ferrero ◽

Eric Lee ◽

Heiner Westphal

Keyword(s):

Transgenic Mice ◽

Plasminogen Activator ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator

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Urokinase-type Plasminogen Activator mRNA is Expressed in Normal Developing Teeth and Leads to Abnormal Incisor Enamel in αMUPA Transgenic Mice

Transgenic Research ◽

10.1007/s11248-006-0006-3 ◽

2006 ◽

Vol 15 (2) ◽

pp. 241-254 ◽

Cited By ~ 12

Author(s):

Ruth Miskin ◽

Tamar Masos ◽

Zipi Shoham ◽

Lisa Williams-Simons

Keyword(s):

Transgenic Mice ◽

Plasminogen Activator ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator

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Hepatic Microenvironment Affects Oval Cell Localization in Albumin-Urokinase-Type Plasminogen Activator Transgenic Mice

American Journal Of Pathology ◽

10.1016/s0002-9440(10)63810-2 ◽

2003 ◽

Vol 162 (1) ◽

pp. 195-202 ◽

Cited By ~ 20

Author(s):

Kristin M. Braun ◽

Anne W. Thompson ◽

Eric P. Sandgren

Keyword(s):

Transgenic Mice ◽

Plasminogen Activator ◽

Oval Cell ◽

Cell Localization ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator

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Extracellular proteolysis alters tooth development in transgenic mice expressing urokinase-type plasminogen activator in the enamel organ

Development ◽

10.1242/dev.126.5.903 ◽

1999 ◽

Vol 126 (5) ◽

pp. 903-912

Author(s):

H.M. Zhou ◽

A. Nichols ◽

A. Wohlwend ◽

I. Bolon ◽

J.D. Vassalli

Keyword(s):

Transgenic Mice ◽

Plasminogen Activator ◽

Transforming Growth Factor ◽

Tooth Development ◽

Enamel Organ ◽

Enamel Formation ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator ◽

Enamel Epithelium ◽

Extracellular Proteolysis

By catalyzing plasmin formation, the urokinase-type plasminogen activator (uPA) can generate widespread extracellular proteolysis and thereby play an important role in physiological and pathological processes. Dysregulated expression of uPA during organogenesis may be a cause of developmental defects. Targeted epithelial expression of a uPA-encoding transgene under the control of the keratin type-5 promoter resulted in enzyme production by the enamel epithelium, which does not normally express uPA, and altered tooth development. The incisors of transgenic mice were fragile, chalky-white and, by scanning electron microscopy, their labial surface appeared granular. This phenotype was attributed to a defect in enamel formation during incisor development, resulting from structural and functional alterations of the ameloblasts that differentiate from the labial enamel epithelium. Immunofluorescence revealed that disorganization of the ameloblast layer was associated with a loss of laminin-5, an extracellular matrix molecule mediating epithelial anchorage. Amelogenin, a key protein in enamel formation, was markedly decreased at the enamel-dentin junction in transgenics, presumably because of an apparent alteration in the polarity of its secretion. In addition, increased levels of active transforming growth factor-beta could be demonstrated in mandibles of transgenic mice. Since the alterations detected could be attributed to uPA catalytic activity, this model provides evidence as to how dysregulated proteolysis, involving uPA or other extracellular proteases, may have developmental consequences such as those leading to enamel defects.

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Thrombolytic and pharmacokinetic properties of an immunoconjugate of single-chain urokinase-type plasminogen activator (u-PA) and a bispecific monoclonal antibody against fibrin and against u-PA in baboons

Blood ◽

10.1182/blood.v79.9.2322.bloodjournal7992322 ◽

1992 ◽

Vol 79 (9) ◽

pp. 2322-2329

Author(s):

Y Imura ◽

JM Stassen ◽

T Kurokawa ◽

S Iwasa ◽

HR Lijnen ◽

...

Keyword(s):

Body Weight ◽

Plasminogen Activator ◽

Autologous Blood ◽

Clot Lysis ◽

Maximal Rate ◽

Antigen Level ◽

Single Chain ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator ◽

Pharmacokinetic Properties

Targeting of plasminogen activators to the fibrin component of a thrombus with the use of monoclonal antibodies (MA) directed against human fibrin may enhance their thrombolytic potency and fibrin- specificity. The thrombolytic and pharmacokinetic properties of rscu- PA/MA-FU1–74, an immunoconjugate of recombinant single-chain urokinase- type plasminogen activator (rscu-PA) and a bispecific MA directed against u-PA and against the beta-chain of human fibrin (MA-FU1–74), were investigated in baboons with a [125I]fibrin-labeled autologous blood clot in the femoral vein. Continuous intravenous infusion of rscu- PA/MA-FU1–74 (1:1.2 molar ratio) over 2 hours showed a fivefold increased thrombolytic potency (lysis per unit dose) over that of unconjugated rscu-PA, as evidenced both by a higher maximal rate of lysis (380% +/- 68% v 78% +/- 25% lysis per mg u-PA equivalent of compound administered per kg body weight, P less than .001), and by a lower dose at which the maximal rate of lysis occurs (0.19 +/- 0.03 v 0.82 +/- 0.10 mg compound per kg body weight, P less than .001). The specific thrombolytic activity (percent lysis per unit steady-state plasma u-PA antigen level) was lower for rscu-PA/MA-FU1–74 than for rscu-PA, as shown by both a lower maximal rate of lysis (60% +/- 13% v 220% +/- 22% lysis per microgram/mL u-PA antigen level in plasma, P less than .001) and a higher plasma antigen level at which maximal lysis is achieved (1.2 +/- 0.17 v 0.20 +/- 0.01 microgram/mL, P less than .001). The thrombolytic potency of rscu-PA/MA-UK1–3, an immunoconjugate of rscu-PA with the parental anti-u-PA antibody was similar to that of unconjugated rscu-PA. Clot lysis was achieved without systemic fibrinogen or alpha 2-antiplasmin consumption, and with a minor transient prolongation of the bleeding time. After the end of the infusions, u-PA-related antigen disappeared from plasma in a biphasic manner, with an initial half-life of 3.3 +/- 0.4 minutes for rscu-PA, 13 +/- 1 minutes for rscu-PA/MA-FU1–74, and 13 +/- 1 minutes for rscu-PA/MA-UK1–3, with corresponding plasma clearances of 340 +/- 28, 10 +/- 1, and 37 +/- 4 mL/min, respectively (mean +/- SEM). rscu- PA/MA-FU1–74 has a fivefold higher thrombolytic potency than unconjugated rscu-PA, as a result both of fibrin targeting by the specific idiotype of the antibody and of a slower plasma clearance.

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