As several forms of lung injury are associated with alveolar fibrin deposition, and fibrin has been pathogenically implicated in the lung fibrotic response, we sought to develop an in vivo gene transfer model of fibrinolytic protease overexpression. To this end, human tissue-type plasminogen activator (t-PA) possesses a high degree of specificity for proteolytic activation of fibrin-bound plasm...

BACKGROUND Excessive fibrin deposition within the inflamed joints of rheumatoid arthritis (RA) patients suggests that local fibrinolysis is inefficient, which seems to be in contrast with the observed increased levels of urokinase type plasminogen activator (u-PA). Thrombin-mediated inactivation of single chain u-PA (scu-PA) into an inactive form called thrombin-cleaved two chain u-PA (tcu-PA/T...

Vascular endothelial cells are thought to be the main source of plasma tissue-type plasminogen activator (t-PA) and von Willebrand factor (VWF). Previous studies have suggested that both t-PA and VWF are acutely released in response to the same stimuli, both in cultured endothelial cells and in vivo. However, the subcellular storage compartment in endothelial cells has not been definitively est...

Fed-batch operation for the production of t-PA using Chinese Hamster Ovary (CHO) cells was optimized using serial and parallel experimentation. The feed, an isotonic concentrate, was improved to obtain 2- to 2.5-fold increases in integrated viable cell days versus batch. With a low glucose inoculum train, the viability index was further increased up to 4.5-fold. Hydrolysates were substituted fo...

The observation that aspirin inhibits the increment in tissue plasminogen activator ft-PA) activity induced by venous occlusion of the forearm became controversial with the publication of several nonconfirmatory studies. The current study was performed to confirm the original observation and determine the mechanism by which aspirin suppresses the incremental t-PA activity induced by venous occl...

We previously showed the involvement of retinoic acid receptor a (RARa) in the induction of tissue-type plasminogen activator (t-PA) synthesis by RA in human umbilical vein endothelial cells (HUVECs). However, the rather slow onset of this induction of t-PA synthesis suggested an indirect role of RARa. Here, we show that the protein synthesis inhibitor, cycloheximide completely blocks the induc...

W'ITithin a short time after the first report on ~ the successful cloning and expression of TV tissue-type plasminogen activator (t-PA),l several laboratories began working on creating new t-PA derivatives through site-directed mutagenesis.2-4 t-PA has unique properties that make it an attractive choice for thrombolytic therapy. t-PA is "fibrin directed"; that is, it preferentially activates th...

Two differently timed extracellular and intracellular enzymatic and mRNA peaks of tissue-type plasrninogen activator (t-PA) were induced following ionizing radiation. The first peak appeared within 10 min following \-irradiation but rapidly declined. The appearance of early tPA mRNA transcripts and enzymatic activity were not prevented by actinomycin D treatment. In contrast, cycloheximide prev...

We evaluated the possible role of NO in modulating tissue plasminogen activator (t-PA) release in the forearm microcirculation of normotensive subjects and hypertensive patients. Essential hypertensive patients are characterized by endothelial dysfunction because of a reduced NO availability and also show an impaired t-PA release. In healthy volunteers and essential hypertensive patients, we st...

Statins are cholesterol-lowering drugs that exert pleiotropic effects which include changes in the plasminogen activation (PA) system of endothelial cells (EC). It was the objective of this study to investigate the signal transduction pathways by which statins increase the expression of tissue-type PA (t-PA) and decrease PA inhibitor type 1 (PAI-1) in human umbilical vein EC. Fluvastatin treatm...