Adenovirus-mediated transfer of tissue-type plasminogen activator augments thrombolysis in tissue-type plasminogen activator-deficient and plasminogen activator inhibitor-1-overexpressing mice.
Impaired fibrinolysis, resulting from increased plasminogen activator inhibitor-1 (PAI-1) or reduced tissue-type plasminogen activator (t-PA) plasma levels, may predispose the individual to subacute thrombosis in sepsis and inflammation. The objective of these studies was to show that adenovirus-mediated gene transfer could increase systemic plasma t-PA levels and thrombolytic capacity in animal model systems. Recombinant adenovirus vectors were constructed that express either human wild type or PAI-1-resistant t-PA from the cytomegalovirus (CMV) promoter. Both t-PA-deficient (t-PA(-/-)) and PAI-1-overexpressing transgenic mice were infected by intravenous injection of these viruses. Intravenous injection of recombinant adenovirus resulted in liver gene transfer, t-PA synthesis, and secretion into the plasma. Virus dose, human t-PA antigen, and activity concentrations in plasma and extent of lysis of a 125I-fibrin-labeled pulmonary embolism were all closely correlated. Plasma t-PA antigen and activity were increased approximately 1,000-fold above normal levels. Clot lysis was significantly increased in mice injected with a t-PA-expressing virus, but not in mice injected with saline or an irrelevant adenovirus. Comparable levels of enzyme activity and clot lysis were obtained with wild type and inhibitor-resistant t-PA viruses. Adenovirus-mediated t-PA gene transfer was found to augment clot lysis as early as 4 hours after infection, but expression levels subsided within 7 days. Adenovirus-mediated transfer of a t-PA gene can effectively increase plasma fibrinolytic activity and either restore (in t-PA-deficient mice) or augment (in PAI-1-overexpressing mice) the thrombolytic capacity in simple animal models of defective fibrinolysis.
Carmeliet
P
P
Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, KU Leuven, Belgium.
Stassen
J M
JM
Van Vlaenderen
I
I
Meidell
R S
RS
Collen
D
D
Gerard
R D
RD
D000256:Adenoviridae; D000483:Alleles; D000818:Animals; D002478:Cells, Cultured; D005342:Fibrinolysis / Q000187:drug effects; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013927:Thrombosis / Q000628:therapy*; D010959:Tissue Plasminogen Activator / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
D017395:Plasminogen Activator Inhibitor 1; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator