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Insulin and insulin-like growth factor I exert different effects on plasminogen activator production or cell growth in the ovine thyroid cell line OVNIS.  

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Insulin and Insulin-like Growth Factor I (IGF-I) are evaluated for their capacity to affect cell proliferation and plasminogen activator (PA) activity production in an ovine thyroid cell line OVNIS. Insulin at physiological and supraphysiological doses induces cell proliferation and increases PA activity. IGF-I, which is also clearly mitogenic for these cells, surprisingly does not modulate PA activity. The results indicate that the growth promoting effect is mediated through the insulin and IGF-I receptors whereas PA activity is solely regulated via the insulin receptors. PMID:1802921

Degryse, B; Maisonobe, F; Hovsépian, S; Fayet, G

1991-11-01

2

Plasminogen activation and cancer  

DEFF Research Database (Denmark)

Breakdown of the extracellular matrix is crucial for cancer invasion and metastasis. It is accomplished by the concerted action of several proteases, including the serine protease plasmin and a number of matrix metalloproteases.The activity of each of these proteases is regulated by an array of activators, inhibitors and cellular receptors.Thus, the generation of plasmin involves the pro-enzyme plasminogen, the urokinase type plasminogen activator uPA and its pro-enzyme pro-uPA, the uPA inhibitor PAI-1, the cell surface uPA receptor uPAR, and the plasmin inhibitor a2 -antiplasmin. Furthermore, the regulation of extracellular proteolysis in cancer involves a complex interplay between cancer cells and non-malignant stromal cells in the expression of the molecular components involved. For some types of cancer, this cellular interplay mimics that observed in the tissue of ori- gin during non-neoplastic tissue remodelling processes.We propose that cancer invasion can be considered as uncontrolled tissue remodelling. Inhibition of extracellular proteases is an attractive approach to cancer therapy. Because proteases have many different functions in the normal organism, efficient inhibition will have toxic side effects.In cancer invasion, like in normal tissue remodelling processes, there appears to be a functional overlap between different extracellular proteases.This redundancy means that combinations of protease inhibitors must be used. Such combination therapy, however, is also likely to increase toxicity.Therefore for each type of cancer, a combination of protease inhibitors that is optimised with respect to both maximal therapeutic effect and minimal toxic side effects need to be identified.

DanØ, Keld; Behrendt, N.

2005-01-01

3

Characterization of plasmin, plasminogen and plasminogen activator in goat milk  

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Full Text Available Plasmin (PL, a serine-proteinase, appears to be the predominant native proteinase in milk and it is mainly associated to casein micelles which represent its substrate (Bastian and Brown, 1996. Plasmin occurs in milk together with its inactive zymogene, plasminogen (PG (Bastian et al. 1991. The cascade of reactions leading to plasminogen activation is regulated by a complex network of molecular interactions between plasminogen activators (PA (tissue-type and urokinase-type and at least three types of specific PA inhibitors (Politis, 1996. Stage of lactation affects PL and PA activities: late lactation is associated with higher activity of PL and PA (Baldi et al., 1996. Plasmin in milk is responsible for the hydrolysis of ?- and ?-caseins (Aslam and Hurley, 1997; Trujillo et al., 1997...

F. Polidori

2011-03-01

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Fibrin-targeted plasminogen activation by plasminogen activator, PadA, from Streptococcus dysgalactiae.  

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Bacterial plasminogen activators differ from each other in their mechanism of plasminogen activation besides their host specificity. Three-domain streptokinase (SK) and two-domain PauA generate nonproteolytic active site center in their cognate partner plasminogen but their binary activator complexes are resistant to ?2-antiplasmin (a2AP) inhibition causing nonspecific plasminogen activation in plasma. In contrast, single-domain plasminogen activator, staphylokinase (SAK), requires proteolytic cleavage of human plasminogen into plasmin for the active site generation, and this activator complex is inhibited by a2AP. The single-domain plasminogen activator, PadA, from Streptococcus dysgalatiae, having close sequence and possible structure homology with SAK, was recently reported to activate bovine Pg in a nonproteolytic manner similar to SK. We report hereby that the binary activator complex of PadA with bovine plasminogen is inhibited by a2AP and PadA is recycled from this complex to catalyze the activation of plasminogen in the clot environment, where it is completely protected from a2AP inhibition. Catalytic efficiency of the activator complex formed by PadA and bovine plasminogen is amplified several folds in the presence of cyanogen bromide digested fibrinogen but not by intact fibrinogen indicating that PadA may be highly efficient at the fibrin surface. The present study, thus, demonstrates that PadA is a unique single-domain plasminogen activator that activates bovine plasminogen in a fibrin-targeted manner like SAK. The sequence optimization by PadA for acquiring the characteristics of both SK and SAK may be exploited for the development of efficient and fibrin-specific plasminogen activators for thrombolytic therapy. PMID:24639287

Singh, Satish; Bhando, Timsy; Dikshit, Kanak L

2014-06-01

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Plasminogen activator inhibitor-1 impairs plasminogen activation-mediated vascular smooth muscle cell apoptosis.  

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The role of plasminogen activator inhibitor-1 (PAI-1) in vascular smooth muscle cell (VSMC) apoptosis mediated by plasminogen activation was studied with the use of aorticVSMC derived from mice with deficiency of PAI-1 (PAI-1 (-/-) ), tissue-type (t-PA (-/-) ) or urokinase-type (u-PA (-/-) ) plasminogen activator or from wildtype (WT) mice with corresponding genetic background. Plasminogen incubated with confluent VSMC was activated in a concentration-dependent and saturable manner for all four cell types, with maximal activation rates that were comparable for WT, u-PA (-/-) and t-PA (-/-) cells, but about two-fold higher for PAI-1 (-/-) cells. Plasminogen activation was impaired by addition of the lysine analogue 6-aminohexanoic acid, and by addition of t-PA and u-PA neutralizing antibodies, suggesting that it depends on binding to cell surface COOH-terminal lysine residues, and on plasminogen activator activity. Morphological alterations consistent with apoptosis were observed much earlier in PAI-1 (-/-) than in WT VSMC. Without addition of plasminogen, the apoptotic index was similar for all four cell types, whereas after incubation with physiological plasminogen concentrations, it was greater in PAI-1 (-/-) VSMC, as compared to WT, t-PA (-/-) or u-PA (-/-) VSMC. Furthermore, the apoptotic rate paralleled the release of plasmin. Thus, plasmin-mediated apoptosis of VSMC occurs via plasminogen activation by either t-PA or u-PA and is impaired by PAI-1. PMID:17080225

Rossignol, Patrick; Anglès-Cano, Eduardo; Lijnen, Henri Roger

2006-11-01

6

Characterization of PauB, a novel broad-spectrum plasminogen activator from Streptococcus uberis.  

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A bovine plasminogen activator of atypical molecular mass ( approximately 45 kDa) from Streptococcus uberis strain SK880 had been identified previously (L. B. Johnsen, K. Poulsen, M. Kilian, and T. E. Petersen. Infect. Immun. 67:1072-1078, 1999). The strain was isolated from a clinical case of bovine mastitis. The isolate was found not to secrete PauA, a bovine plasminogen activator expressed by the majority of S. uberis strains. Analysis of the locus normally occupied by pauA revealed an absence of the pauA open reading frame. However, an alternative open reading frame was identified within the same locus. Sequence analysis of the putative gene suggested limited but significant homology to other plasminogen activators. A candidate signal peptide sequence and cleavage site were also identified. Expression cloning of DNA encoding the predicted mature protein (lacking signal peptide) confirmed that the open reading frame encoded a plasminogen activator of the expected size, which we have named PauB. Both native and recombinant forms of PauB displayed an unexpectedly broad specificity profile for bovine, ovine, equine, caprine, porcine, rabbit, and human plasminogen. Clinical and nonclinical field isolates from nine United Kingdom sites were screened for the pauB gene and none were identified as carrying it. Similarly, clinical isolates from 20 Danish herds were all found to encode PauA and not PauB. Therefore, PauB represents a novel but rare bacterial plasminogen activator which displays very broad specificity. PMID:11741851

Ward, Philip N; Leigh, James A

2002-01-01

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Plasminogen Activator Promotes Recovery Following Spinal Cord Injury  

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Plasminogen activators play an important role in synaptic plasticity associated with the crossed phrenic phenomenon (CPP) and recovery of respiratory function after spinal cord injury. A genetic approach using knockout mice lacking various genes in the plasminogen activator/plasmin system has shown that induction of urokinase plasminogen activator (uPA) is required during the first hour after a C2-hemisection for the acquisition of the CPP response. The uPA knockout mice do not show the struc...

Seeds, Nicholas; Mikesell, Steve; Vest, Rebekah; Bugge, Thomas; Schaller, Kristin; Minor, Kenneth

2011-01-01

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Complex interactions between bovine plasminogen and streptococcal plasminogen activator PauA.  

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The interactions between bovine plasminogen and the streptococcal plasminogen activator PauA that culminate in the generation of plasmin are not fully understood. Formation of an equimolar activation complex comprising PauA and plasminogen by non-proteolytic means is a prerequisite to the recruitment of substrate plasminogen; however the determinants that facilitate these interactions have yet to be defined. A mutagenesis strategy comprising nested deletions and random point substitutions indicated roles for both amino and carboxyl-terminal regions of PauA and identified further essential residues within the alpha domain of the plasminogen activator. A critical region within the alpha domain was identified using non-overlapping PauA peptides to block the interaction between PauA and bovine plasminogen, preventing formation of the activation complex. Homology modelling of the activation complex based upon the known structures of streptokinase complexed with human plasmin supported these findings by placing critical residues in close proximity to the plasmin component of the activation complex. PMID:15351638

Ward, Philip N; Field, Terence R; Rosey, Everett L; Abu-Median, Abu-Bakr; Lincoln, Ruth A; Leigh, James A

2004-09-24

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Inactivation of plasminogen activator inhibitor by oxidants  

International Nuclear Information System (INIS)

The rapidly acting plasminogen activator inhibitor (PAI) purified from cultured bovine endothelial cells (BAEs) was inactivated during iodination with chloramine T and other oxidizing iodination systems. Inactivation was observed in the absence of iodine, suggesting that the loss of activity resulted from the oxidizing conditions employed. In an attempt to further study the nature of this inactivation, the PAI was treated with chloramine T under conditions that specifically oxidize methionine and cystein residues. Both PAI inhibitory activity and the ability of the PAI to form complexes with tissue-type PA were decreased in a dose-dependent manner by such treatment. PAI activity was measured with the lysis of 125I-labelled fibrin. The reductase is a DTT-dependent enzyme that specifically converts methionine sulfoxide to methionine. Little activity was restored by either the reductase or DTT alone. These results indicate that the oxidation of at least one critical methionine residue is responsible for the loss of PAI activity upon iodination. In this respect, the BAE PAI resembles ?1-protease inhibitor, a well-characterized elastase inhibitor that also is inactivated by oxidants. Both inhibitors are members of the serine protease inhibitor superfamily (Serpins), and both have a methionine residue in their reactive center

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Tissue plasminogen activator and urokinase plasminogen activator in human epileptogenic pathologies.  

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A growing body of evidence demonstrates the involvement of plasminogen activators (PAs) in a number of physiologic and pathologic events in the CNS. Induction of both tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) has been observed in different experimental models of epilepsy and tPA has been implicated in the mechanisms underlying seizure activity. We investigated the expression and the cellular distribution of tPA and uPA in several epileptogenic pathologies, including hippocampal sclerosis (HS; n=6), and developmental glioneuronal lesions, such as focal cortical dysplasia (FCD, n=6), cortical tubers in patients with the tuberous sclerosis complex (TSC; n=6) and in gangliogliomas (GG; n=6), using immuno-cytochemical, western blot and real-time quantitative PCR analysis. TPA and uPA immunostaining showed increased expression within the epileptogenic lesions compared to control specimens in both glial and neuronal cells (hippocampal neurons in HS and dysplastic neurons in FCD, TSC and GG specimens). Confocal laser scanning microscopy confirmed expression of both proteins in astrocytes and microglia, as well as in microvascular endothelium. Immunoblot demonstrated also up-regulation of the uPA receptor (uPAR; P<0.05). Increased expression of tPA, uPA, uPAR and tissue PA inhibitor type mRNA levels was also detected by PCR analysis in different epileptogenic pathologies (P<0.05). Our data support the role of PA system components in different human focal epileptogenic pathologies, which may critically influence neuronal activity, inflammatory response, as well as contributing to the complex remodeling of the neuronal networks occurring in epileptogenic lesions. PMID:20219643

Iyer, A M; Zurolo, E; Boer, K; Baayen, J C; Giangaspero, F; Arcella, A; Di Gennaro, G C; Esposito, V; Spliet, W G M; van Rijen, P C; Troost, D; Gorter, J A; Aronica, E

2010-05-19

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Epithelial glycoprotein-330 mediates endocytosis of plasminogen activator-plasminogen activator inhibitor type-1 complexes  

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Epithelial glycoprotein 330 (gp330) is structurally similar to the multifunctional alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP), gp330 and alpha 2MR/LRP bind Ca2+ with high affinity, and both receptors bind and mediate endocytosis of alpha 2MR-associated protein (RAP). In the present report, we describe that affinity-purified gp330 from rabbit renal cortex binds plasminogen activator inhibitor type-1 (PAI-1) complexed with urokinase-type plasminogen activator (uPA). alpha 2M-methylamine, which binds with high affinity to alpha 2MR/LRP, did not bind to gp330. The apparent Kd for binding of uPA.PAI-1 complexes was about 0.8 nM at 4 degrees C. The binding was calcium-dependent and inhibited by recombinant RAP (rRAP) and tissue type plasminogen activator-PAI-1 complexes. Thin sections of rabbit renal proximal tubules bound 125I-labeled uPA.PAI-1 and rRAP in the apical part of proximal tubules corresponding to the localization of gp330. The binding of 125I-uPA.PAI-1 complexes in tubules was abolished by excess unlabeled rRAP, and a rRAP-inhibitable endocytosis and degradation of labeled uPA.PAI-1 complexes was demonstrated by perfusion of isolated rabbit proximal tubules. The results establish an endocytotic function of gp330 and suggest that gp330 is an important component of the fibrinolytic system in gp330-containing epithelial as found in, for example, kidney and lung.

Moestrup, S K; Nielsen, Susanne

1993-01-01

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Plasminogen activator inhibitor-1 in aging.  

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Plasminogen activator inhibitor-1 (PAI-1), a principal inhibitor of fibrinolysis, is induced in thrombotic, fibrotic, and cardiovascular diseases, which in turn primarily afflict the older population. This induction of PAI-1 may play an important role in the pathology of these diseases as PAI-1 can regulate the dissolution of fibrin and also inhibit the degradation of the extracellular matrix by reducing plasmin generation. PAI-1 expression is elevated in aged individuals and is significantly upregulated in a variety of pathologies associated with the process of aging, including myocardial and cerebral infarction, vascular (athero) sclerosis, cardiac and lung fibrosis, metabolic syndromes (e.g., hypertension, hyperlipidemia, and insulin resistance), cancer, and inflammatory/stress responses. Thus, PAI-1 may play a critical role in the development of aging-associated pathological changes. In addition, PAI-1 is recognized as a marker of senescence and a key member of a group of proteins collectively known as the senescence-messaging secretome. In this review, we highlight the role of PAI-1 in the pathophysiology of aging and aging-associated disorders. PMID:25122500

Yamamoto, Koji; Takeshita, Kyosuke; Saito, Hidehiko

2014-09-01

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Assembly of urokinase receptor-mediated plasminogen activation complexes involves direct, non-active-site interactions between urokinase and plasminogen.  

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The binding of the zymogenic form of urokinase-type plasminogen activator (pro-uPA) to its specific cellular receptor, uPAR, leads to a large potentiation of plasmin generation. This is dependent on the concurrent cellular binding of plasminogen, and is completely abrogated by the plasminogen lysine-binding site ligand, 6-aminohexanoic acid. Previous data have provided circumstantial evidence for the formation of specific complexes to mediate the kinetically favorable reciprocal interactions between the protease and zymogen components [Ellis, V., and Dano, K. (1993) J. Biol. Chem. 268, 4806-4813]. To further investigate the formation of these putative complexes, we have studied the effect of various lysine-binding site ligands on the binding and activation of plasminogen on U937 cells. Lysine-binding site ligands resembling internal lysine residues, such as Nalpha-acetyl-L-lysine methyl ester, were found to specifically inhibit uPAR-mediated cell-surface plasminogen activation at concentrations up to 40-fold lower than those inhibiting the cellular binding of 125I-labeled plasminogen (IC50s 300 microM vs 8.5 mM). By contrast, 6-aminohexanoic acid, resembling a C-terminal lysine residue, did not display this disparity (IC50s 25 vs 30 microM). These lysine analogues were also found to compete a non-active-site interaction between uPA and plasminogen, detected by surface plasmon resonance (Kd 50 nM), at concentrations correlating with their effect on cell-surface plasminogen activation, suggesting that this interaction is part of the kinetic mechanism. Consistent with this, synthetic peptides corresponding to the sequence uPA149-158 (GQKTLRPRFK) and uPA149-157 (GQKTLRPRF) specifically abolished the amplification of cell-surface plasminogen activation. These data demonstrate that a novel non-active-site interaction between uPA and plasminogen is necessary for the assembly and efficiency of cell-surface plasminogen activation complexes. PMID:9888805

Ellis, V; Whawell, S A; Werner, F; Deadman, J J

1999-01-12

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The Glycosylation of Plasminogen Activator Inhibitor-1  

DEFF Research Database (Denmark)

Plasminogen activator inhibitor type-1 (PAI-1) has three potential sites for N-linked glycosylation, including Asn209Tyr210Thr211, Asn265Met266Thr267, and Asn329Glu330Ser331. Using a HEK293 expression system, we have made mutants with Asp or Gln substitutions of the Asn residue in each of these sequences. Analyses of these mutants for the content of N-acetyl glucosamine showed that Asn209 and Asn265, but not Asn329, are glycosylated, in agreement with previous suggestions made on the basis of X-ray crystal structure analysis of PAI-1 expressed in CHO cells (Xue et al. (1998) Structure 6, 627-636). In contrast, PAI-1, containing a total of 26 Ser and 26 Thr residues, which are potential targets for O-linked glycosylation, was found to be devoid of N-acetyl-galactosamine, demonstrating the absence of O-linked glycosylation. Analysis of PAI-1 variants with mutational inactivation of each of the sequences utilized for N-linked glycosylation by Fluorophore Assisted Carbohydrate Electrophoresis (FACE), showed a different N-linked glycosylation profile of the glycans at each of the 2 sites. The exact structure of the carbohydrate chains at each of these 2 sequences are being determined using MALDI mass spectrometry and monosaccharide composition analysis and compared to that of natural and recombinant PAI-1 from other sources. These results contribute to a structural basis for previous observations of a different functional importance of the N-linked glycosylation at each of the 2 sequences.

Skottrup, Peter

15

PauA: a novel plasminogen activator from Streptococcus uberis.  

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Chromosomal DNA from two geographically distinct isolates of Streptococcus uberis was used to clone the plasminogen activator in an active form in Escherichia coli. The cloned fragments from each strain contained four potential open reading frames (ORFs). That for the plasminogen activator encoded a protein of 286 amino acids (33.4 kDa) which is cleaved between residues 25 and 26 during secretion by S. uberis. The amino acid sequence of the mature protein showed only weak homology (23.5-28%) to streptokinase. The plasminogen activator gene, pauA, in S. uberis was located between two ORFs with high homology to the DNA mismatch repair genes, hexA and hexB, and not on a DNA fragment between the genes encoding an ATP binding cassette transporter protein (abc) and a protein involved in the formation and degradation of guanosine polyphosphates (rel) as is the case for streptokinase in other streptococci. PMID:10483719

Rosey, E L; Lincoln, R A; Ward, P N; Yancey, R J; Leigh, J A

1999-09-01

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Structural basis for recognition of urokinase-type plasminogen activator by plasminogen activator inhibitor-1  

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Plasminogen activator inhibitor-1 (PAI-1), together with its physiological target urokinase-type plasminogen activator (uPA), plays a pivotal role in fibrinolysis, cell migration, and tissue remodeling and is currently recognized as being among the most extensively validated biological prognostic factors in several cancer types. PAI-1 specifically and rapidly inhibits uPA and tissue-type PA (tPA). Despite extensive structural/functional studies on these two reactions, the underlying structural mechanism has remained unknown due to the technical difficulties of obtaining the relevant structures. Here, we report a strategy to generate a PAI-1·uPA(S195A) Michaelis complex and present its crystal structure at 2.3-Å resolution. In this structure, the PAI-1 reactive center loop serves as a bait to attract uPA onto the top of the PAI-1 molecule. The P4-P3' residues of the reactive center loop interact extensively with the uPA catalytic site, accounting for about two-thirds of the total contact area. Besides the active site, almost all uPA exosite loops, including the 37-, 60-, 97-, 147-, and 217-loops, are involved in the interaction with PAI-1. The uPA 37-loop makes an extensive interaction with PAI-1 ?-sheet B, and the 147-loop directly contacts PAI-1 ?-sheet C. Both loops are important for initial Michaelis complex formation. This study lays down a foundation for understanding the specificity of PAI-1 for uPA and tPA and provides a structural basis for further functional studies.

Lin, Zhonghui; Jiang, Longguang

2011-01-01

17

Dehydroepiandrosterone reduces plasma plasminogen activator inhibitor type 1 and tissue plasminogen activator antigen in men.  

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Dehydroepiandrosterone (DHEA) may help prevent heart disease in men. To test the hypothesis that DHEA might exert its effects by enhancing endogenous fibrinolytic potential, a double-blind, placebo-controlled study was conducted that assessed the effects of DHEA administration on plasma plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) antigen. Eighteen men received 50 mg DHEA orally and 16 men received a placebo capsule thrice daily for 12 days. Serum DHEA-sulfate and plasma PAI-1 and tPA antigen were measured before and after treatment. In the DHEA group, serum DHEA-sulfate (from 7.5 +/- 1.2 micromol/L to 20.2 +/- 1.5 micromol/L (P < 0.0001), androstenedione (from 2.6 +/- 0.2 nmol/L to 4.0 +/- 0.4 nmol/L; P < 0.005) and estrone (from 172 +/- 21 pmol/L to 352 +/- 28 pmol/L; P < 0.005) increased, whereas plasma PAI-1 (from 55.4 +/- 3.8 ng/mL to 38.6 +/- 3.3 ng/mL; P < 0.0001) and tPA antigen (from 8.1 +/- 1.9 ng/mL to 5.4 +/- 1.3 ng/mL; P < 0.0005) decreased. In the placebo group, serum DHEA-sulfate declined slightly from 8.0 +/- 3.3 micromol/L to 7.3 +/- 3.4 micromol/L (P < 0.05), but no other measured steroid changed. Plasma PAI-1 and tPA antigen did not change in the placebo group. These findings suggest that DHEA administration reduces plasma PAI-1 and tPA antigen concentrations in men. PMID:8615394

Beer, N A; Jakubowicz, D J; Matt, D W; Beer, R M; Nestler, J E

1996-05-01

18

Recombinant tissue plasminogen activator for acute ischemic stroke.  

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Stroke is a leading cause of serious and long-term disability and death worldwide, with approximately 750,000 strokes occurring annually in the United States of America. The risk of stroke doubles each decade for people over 55 years. Cerebral angiography conducted soon after the onset of stroke demonstrates arterial occlusion in 70%-80% of cases. Recanalization of an occluded cerebral artery may assist in the recovery of reversibly ischemic tissue and limit the neurological disability. In June 1996, the recombinant tissue plasminogen activator was approved as a safe and an effective intravenous treatment for acute ischemic stroke, especially if given within 3 hours of onset of symptoms. Since approval, less than 5% of all stroke patients are receiving recombinant tissue plasminogen activator. In this review we try to answer the question of whether recombinant tissue plasminogen activator therapy should be the first-line treatment for acute ischemic stroke. The result of major recombinant tissue plasminogen activator trials will be summarized and reviewed critically.

Amira R. Al-Buhairi

2002-01-01

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The tissue-type plasminogen activator-plasminogen activator inhibitor 1 complex promotes neurovascular injury in brain trauma: evidence from mice and humans  

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The neurovascular unit provides a dynamic interface between the circulation and central nervous system. Disruption of neurovascular integrity occurs in numerous brain pathologies including neurotrauma and ischaemic stroke. Tissue plasminogen activator is a serine protease that converts plasminogen to plasmin, a protease that dissolves blood clots. Besides its role in fibrinolysis, tissue plasminogen activator is abundantly expressed in the brain where it mediates extracellular proteolysis. However, proteolytically active tissue plasminogen activator also promotes neurovascular disruption after ischaemic stroke; the molecular mechanisms of this process are still unclear. Tissue plasminogen activator is naturally inhibited by serine protease inhibitors (serpins): plasminogen activator inhibitor-1, neuroserpin or protease nexin-1 that results in the formation of serpin:protease complexes. Proteases and serpin:protease complexes are cleared through high-affinity binding to low-density lipoprotein receptors, but their binding to these receptors can also transmit extracellular signals across the plasma membrane. The matrix metalloproteinases are the second major proteolytic system in the mammalian brain, and like tissue plasminogen activators are pivotal to neurological function but can also degrade structures of the neurovascular unit after injury. Herein, we show that tissue plasminogen activator potentiates neurovascular damage in a dose-dependent manner in a mouse model of neurotrauma. Surprisingly, inhibition of activity following administration of plasminogen activator inhibitor-1 significantly increased cerebrovascular permeability. This led to our finding that formation of complexes between tissue plasminogen activator and plasminogen activator inhibitor-1 in the brain parenchyma facilitates post-traumatic cerebrovascular damage. We demonstrate that following trauma, the complex binds to low-density lipoprotein receptors, triggering the induction of matrix metalloproteinase-3. Accordingly, pharmacological inhibition of matrix metalloproteinase-3 attenuates neurovascular permeability and improves neurological function in injured mice. Our results are clinically relevant, because concentrations of tissue plasminogen activator: plasminogen activator inhibitor-1 complex and matrix metalloproteinase-3 are significantly elevated in cerebrospinal fluid of trauma patients and correlate with neurological outcome. In a separate study, we found that matrix metalloproteinase-3 and albumin, a marker of cerebrovascular damage, were significantly increased in brain tissue of patients with neurotrauma. Perturbation of neurovascular homeostasis causing oedema, inflammation and cell death is an important cause of acute and long-term neurological dysfunction after trauma. A role for the tissue plasminogen activator–matrix metalloproteinase axis in promoting neurovascular disruption after neurotrauma has not been described thus far. Targeting tissue plasminogen activator: plasminogen activator inhibitor-1 complex signalling or downstream matrix metalloproteinase-3 induction may provide viable therapeutic strategies to reduce cerebrovascular permeability after neurotrauma. PMID:22822039

Sashindranath, Maithili; Sales, Eunice; Daglas, Maria; Freeman, Roxann; Samson, Andre L.; Cops, Elisa J.; Beckham, Simone; Galle, Adam; McLean, Catriona; Morganti-Kossmann, Cristina; Rosenfeld, Jeffrey V.; Madani, Rime; Vassalli, Jean-Dominique; Su, Enming J.; Lawrence, Daniel A.

2012-01-01

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Diagnostic value of plasminogen activity level in acute mesenteric ischemia  

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Full Text Available AIM: To investigate the changes in plasminogen activity level during mesenteric ischemia.METHODS: We performed laparotomy in 90 female Wistar-Albino rats (average weight 230 g. In sham groups (SL (GroupsIand II the superior mesenteric artery (SMA and vein (SMV were explored, but not tied. In SMA groups (Groups III and IV the SMA was ligated, and in SMV groups (Groups V and VI the SMV was ligated. On re-laparotomy 2 mL of blood was drawn at 1 h in groupsI, III and V, and at 3 h in groups II, IV and VI. Plasminogen levels were assessed and comparisons were made between groups and within each group.RESULTS: The mean plasminogen activity in the SL group was significantly higher than SMA (25.1 ± 10.8 vs 11.8 ± 4.6, P < 0.001 or SMV (25.1 ± 10.8 vs 13.7 ± 4.4, P < 0.001 groups both at 1 h and at 3 h (29.8 ± 8.9 vs 15.1 ± 5.7, P < 0.0001; 29.8 ± 8.9 vs 14.2 ± 2.9, P < 0.0001. There were no significant differences between the values of SMA and SMV groups at 1 h (P = 0.28 and at 3 h (P = 0.71. In each group, plasminogen activity levels did not change significantly between the two measurements performed at 1 h and 3 h.CONCLUSION: We conclude that blood plasminogen activities decrease during early phases of both arterial and venous mesenteric ischemia which may be a useful marker for early diagnosis.

Yusuf Gunerhan, Neset Koksal, Munire Kayahan, Yavuz Eryavuz, Hilal Sekban

2008-04-01

 
 
 
 
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Nonlysine-analog plasminogen modulators promote autoproteolytic generation of plasmin(ogen) fragments with angiostatin-like activity.  

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We recently discovered several nonlysine-analog conformational modulators for plasminogen. These include SMTP-6, thioplabin B and complestatin that are low molecular mass compounds of microbial origin. Unlike lysine-analog modulators, which increase plasminogen activation but inhibit its binding to fibrin, the nonlysine-analog modulators enhance both activation and fibrin binding of plasminogen. Here we show that some nonlysine-analog modulators promote autoproteolytic generation of plasmin(ogen) derivatives with its catalytic domain undergoing extensive fragmentation (PMDs), which have angiostatin-like anti-endothelial activity. The enhancement of urokinase-catalyzed plasminogen activation by SMTP-6 was followed by rapid inactivation of plasmin due to its degradation mainly in the catalytic domain, yielding PMD with a molecular mass ranging from 68 to 77 kDa. PMD generation was observed when plasmin alone was treated with SMTP-6 and was inhibited by the plasmin inhibitor aprotinin, indicating an autoproteolytic mechanism in PMD generation. Thioplabin B and complestatin, two other nonlysine-analog modulators, were also active in producing similar PMDs, whereas the lysine analog 6-aminohexanoic acid was inactive while it enhanced plasminogen activation. Peptide sequencing and mass spectrometric analyses suggested that plasmin fragmentation was due to cleavage at Lys615-Val616, Lys651-Leu652, Lys661-Val662, Lys698-Glu699, Lys708-Val709 and several other sites mostly in the catalytic domain. PMD was inhibitory to proliferation, migration and tube formation of endothelial cells at concentrations of 0.3-10 microg.mL(-1). These results suggest a possible application of nonlysine-analog modulators in the treatment of cancer through the enhancement of endogenous plasmin(ogen) fragment formation. PMID:14764098

Ohyama, Shigeki; Harada, Tomotaka; Chikanishi, Toshihiro; Miura, Yutaka; Hasumi, Keiji

2004-02-01

22

Plasminogen activator inhibitor-1 in kidney pathology (Review).  

Science.gov (United States)

Plasminogen activator inhibitor type-1 (PAI-1) inhibits tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA), which convert plasminogen to plasmin, a strong proteolytic enzyme. Thus, PAI-1 is a primary and negative regulator of plasmin-driven proteolysis. In addition to its main role as an inhibitor of fibrinolysis, PAI?1 has been implicated as a mediator in other processes, including fibrosis, rheumatoid arthritis, atherosclerosis, tumor angiogenesis and bacterial infections. It also significantly modulates cellular adhesion or migration, wound healing, angiogenesis and tumor cell metastasis. However, in the present study, we have reviewed the literature in relation to different kidney diseases where PAI-1 regulates fibrinolysis and acts independently of proteolysis. PAI-1 is normally produced in trace amounts in healthy kidneys but is synthesized in a wide variety of both acute and chronic diseased kidneys. We reviewed the role of PAI-1 in diabetic kidney nephropathy, chronic kidney disease, hemodialysis, peritoneal dialysis and in kidney transplantation. Increased PAI-1 expression results in accumulation of extracellular matrix (ECM) leading to numerous kidney diseases. Predisposition to some diseases is due to the genetic role of PAI-1 in their development. A number of studies demonstrated that the inhibition of PAI-1 activity or therapy with a mutant PAI-1 increases matrix turnover and reduces glomerulosclerosis by competing with endogenous PAI-1. This strongly suggests that PAI-1 is a valid target in the treatment of fibrotic renal disease. However, net proteolytic activity depends on the delicate balance between its negative regulation by PAI-1 and activation by uPA and tPA. Also, plasmin activated by its inhibitors upregulates activity of other enzymes. Thus, assessment of prognosis for the diseased kidney should include a variety of proteolysis regulators and enzymes. PMID:23314920

Ma?gorzewicz, Sylwia; Skrzypczak-Jankun, Ewa; Jankun, Jerzy

2013-03-01

23

Clot penetration and retention by plasminogen activators promote fibrinolysis.  

Science.gov (United States)

Tissue-type plasminogen activator (tPA) remains the sole thrombolytic approved by the FDA for the treatment of pulmonary embolism (PE). tPA has not been replaced by third generation plasminogen activators, e.g. Reteplase (Ret) and Tenecteplase (TNK) that circulate with longer life-spans and in theory should have more extended potency in vivo. One reason for this paradox is the inability to assign units of activity to plasminogen activators based on specific biologically relevant standards, which impairs objective comparison. Here, we compare clot permeation, retention and fibrinolytic activities of tPA, TNK and Ret in vitro and clot composition over time with outcome in a mouse model of disseminated pulmonary microembolism (ME). When clots were incubated in the continuous presence of drug, tPA, TNK and Ret lysed fibrin clots identically in the absence of PA inhibitor-1 (e.g. PAI-1). Ret, which has lower fibrin affinity and greater susceptibility to inhibition by PAI-1 than tPA, was less effective in lysing plasma clots, while TNK was less effective when the fibrin content of the clots was enhanced. However, when clots were afforded only brief exposure to drug, as occurs in vivo, Ret showed more extensive clot permeation, greater retention and lysis than tPA or TNK. These results were reproduced in vivo in a mouse model of ME. These studies indicate the need for more relevant tests of plasminogen activator activity in vitro and in vivo and they show that clot permeation and retention are important potential predictors of clinical utility. PMID:23098998

Marcos-Contreras, O A; Ganguly, K; Yamamoto, A; Shlansky-Goldberg, R; Cines, D B; Muzykantov, V R; Murciano, J-C

2013-01-15

24

Thrombin-specific inactivation of endothelial cell derived plasminogen activator  

International Nuclear Information System (INIS)

Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive 125I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface

25

Mechanism of the action of SMTP-7, a novel small-molecule modulator of plasminogen activation.  

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SMTP-7 is a small molecule that promotes the proteolytic activation of plasminogen by relaxing its conformation. SMTP-7 has excellent therapeutic activities against thrombotic stroke in several rodent models. The objective of this study was to elucidate detailed mechanism of the action of SMTP-7 in vitro. We report here that the action of SMTP-7 requires a cofactor with a long-chain alkyl or alkenyl group, and that the fifth kringle domain (kringle 5) of plasminogen is involved in the SMTP-7 action. In this study, we found that the SMTP-7 action to enhance plasminogen activation depended on the presence of a certain type of surfactant, and we screened biologically relevant molecules for their cofactor activity for the SMTP action. As a result, phospholipids, sphingolipids, and oleic acid were found to be active in assisting the SMTP-7 action. On the contrary, stearic acid and bile acids were inactive. Thus, a certain structural element, not only the surface-activating potential, is required for a compound to act as a cofactor for the SMTP-7 action. The plasminogen molecule consists of a PAN domain, five kringle domains, and a serine protease domain. The cofactor-dependent effects of SMTP-7 was observed with plasminogen species including kringle 5 such as intact plasminogen (Glu-plasminogen), des-PAN plasminogen (Lys-plasminogen), and des-[PAN?-?(kringles 1-4)] plasminogen (mini-plasminogen). However, SMTP-7 effect was not observed with the smallest plasminogen species des-[PAN?-?(kringles 1-4) and a half of kringle 5)] plasminogen (micro-plasminogen). Thus, kringle 5 is crucial for the action of SMTP-7. PMID:24784315

Koyanagi, Keiji; Narasaki, Ritsuko; Yamamichi, Shingo; Suzuki, Eriko; Hasumi, Keiji

2014-06-01

26

The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of human glutamic-plasminogen by tissue plasminogen activator.  

Science.gov (United States)

Earlier studies on the stimulatory effect of fucoidan, heparin, and cyanogen bromide (CNBr)-fibrinogen digest on the in-vitro activation of glutamic type plasminogen by tissue plasminogen activator, which were performed using subphysiologic ionic strengths of buffers, gave inconsistent results because of the variation in the ionic strengths of the buffers used. Studies were therefore conducted on the effect of these cofactors using 0.05 mol/l Tris buffer containing a physiologic concentration of sodium chloride. The double reciprocal plots of the activation of glutamic type plasminogen by tissue plasminogen activator in the presence of fucoidan and 6-aminohexanoic acid (6-AH) or heparin and 6-AH showed a four- to six-fold increase in K(cat), while the K(m) remained unchanged. On the other hand, there was greater than six-fold lowering of K(m) from 0.213 to 0.035 micromol/l in the presence of CNBr-fibrinogen, while K(cat) was only slightly increased. The ratios of the initial rate of plasmin generation in the presence or absence of the cofactors were plotted against the inverse of the volume fraction of glutamic type plasminogen or of tissue plasminogen activator after serial dilution. The results suggested that the enhancements by fucoidan and 6-AH or CNBr-fibrinogen were due to their interactions directed towards glutamic type plasminogen, while for heparin and 6-AH, the interaction was directed towards tissue plasminogen activator. Circular dichroism studies in the near ultraviolet range (250-308 nm) showed that 6-AH enhanced the circular dichroism spectra of glutamic type plasminogen around certain chromophores, while fucoidan and heparin had no effect, suggesting that the enhancement by the cofactors may be related to the favorable conformational changes of glutamic type plasminogen by 6-AH. PMID:12695744

Bell, Jason; Duhon, Shalisha; Doctor, Vasant M

2003-04-01

27

Reduced tissue type plasminogen activator activity of the gastroduodenal mucosa in peptic ulcer disease.  

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The gastroduodenal mucosa has a rich blood supply. An active fibrinolytic system is presumably required to maintain vascular patency, and impairment may result in reduced blood flow, focal tissue necrosis, and peptic ulcerogenesis. Tissue type and urokinase type plasminogen activator activity (expressed as mIU/mg protein) and plasminogen activator inhibitor type-1 antigen were assayed in homogenates of gastric and duodenal biopsy specimens taken from patients with: normal endoscopy (controls)...

Wodzin?ski, M. A.; Bardhan, K. D.; Reilly, J. T.; Cooper, P.; Preston, F. E.

1993-01-01

28

Maspin increases extracellular plasminogen activator activity associated with corneal fibroblasts and myofibroblasts.  

Science.gov (United States)

Maspin, an inhibitor of cell migration and a stimulator of adhesion of cells to the ECM, is synthesized and released by corneal keratocytes into the extracellular matrix. When the cornea is wounded, the quiescent stromal keratocytes underlying the wound undergo apoptosis and cells adjacent to this apoptotic area convert to fibroblasts or myofibroblasts. This study explores the effect of extracellular maspin on the plasminogen-plasminogen activator system of corneal stromal cells following wounding. Treatment of corneal fibroblasts and myofibroblasts with r-maspin increased extracellular but not cell-associated tissue-type plasminogen activator (tPA), urinary-type plasminogen activator (uPA) or plasminogen activator inhibitor-1 (PAI-1). Despite the extracellular increase in PAI-1, the net effect of maspin treatment was an increase in plasminogen activation. At physiological levels, maspin did not alter uPA or tPA mRNA levels, in these cells. The increase in pro and active uPA was due to decreased clearance in the presence of maspin for myofibroblasts but not for fibroblasts. The clearance of pro and active tPA was normal in fibroblasts indicating different mechanisms for the increase of these homologous enzymes in the two cell types. Increased generation of plasmin by maspin treated corneal stromal fibroblasts and myofibroblasts led to conversion of plasminogen to active plasmin degradation products and angiostatin-like molecules. This study suggests that extracellular maspin increased pro and active uPA and tPA released by corneal fibroblasts and myofibroblasts on the short time scale of 1-4 h, but by 24 h there was no increase over the levels produced without maspin. This augmentation of plasminogen activator activity increases plasmin activation and angiostatin generation. It further indicates that the effect of maspin on uPA and tPA levels is cell type dependent. PMID:21810423

Warejcka, Debra J; Narayan, Malathi; Twining, Sally S

2011-11-01

29

Development of irreversible diphenyl phosphonate inhibitors for urokinase plasminogen activator.  

Science.gov (United States)

In this letter we report the synthesis and biochemical evaluation of selective, irreversible diphenyl phosphonate inhibitors for urokinase plasminogen activator (uPA). A diphenyl phosphonate group was introduced on the substratelike peptide Z-d-Ser-Ala-Arg, and modification of the guanidine side chain was investigated. A guanylated benzyl group appeared the most promising side chain modification. A k(app) value in the 10(3) M(-1) s(-1) range for uPA was obtained, together with a selectivity index higher than 240 toward other trypsin-like proteases such as tPA, thrombin, plasmin, and FXa. PMID:15115382

Joossens, J; Van der Veken, P; Lambeir, A-M; Augustyns, K; Haemers, A

2004-05-01

30

Stimulation of radiation-impaired plasminogen activator release by phorbol ester in aortic endothelial cells  

International Nuclear Information System (INIS)

Ionizing radiation has been reported to affect the fibrinolytic activity of exposed tissue. With cultured bovine aortic endothelial cells, radiation suppresses the release of plasminogen activator to the conditioned media, with a concomitant increase in intracellular plasminogen activator. Thus study was undertaken to determine whether radiation-impaired plasminogen activator release can be modified by phorbol ester. We exposed cultured bovine aortic endothelial cells to a sterilizing dose of 10 Gy of gamma-rays and found the treatment led to cell injury, as evidenced by an increased release of prelabeled chromium, and to a reduction of plasminogen activator in the conditioned media with elevated intracellular plasminogen activator in irradiated cells. Phorbol ester enhanced plasminogen activator activity in both sham-irradiated and irradiated endothelial cells. It was interesting to note that the increased plasminogen activator in phorbol ester-stimulated sham-irradiated cells was largely retained inside the cell, while it was released to the conditioned media in irradiated cells. Apparently, altered plasminogen activator activity of radiation-sterilized endothelial cells can be modified by exogenous stimuli

31

Immunomodulatory activity of plant residues on ovine neutrophils.  

Science.gov (United States)

Neutrophils play an essential role in host defense and inflammation. Plants have long been used to improve the immune function, but for most of them specific investigations on animal health are lacking. In the present study, water and hydroethanolic extracts from 11 plant wastes have been screened on immune responses of ovine neutrophils. Eight sheep clinically healthy, not lactating, non-pregnant were selected and used for the experiment. Freshly isolated neutrophils were incubated with the extracts of the residues at increasing doses, and then they were tested for adhesion and superoxide production induced with PMA. The residues of Larix decidua, Thymus vulgaris, Salix alba, Sinupret, Helianthus annuus, Mangifera indica modulated the neutrophil immune functions, moreover, Larix decidua, Thymus vulgaris and Salix alba presented the highest anti-inflammatory activity. PMID:18667240

Farinacci, Maura; Colitti, Monica; Sgorlon, Sandy; Stefanon, Bruno

2008-11-15

32

[Polymorphism of the plasminogen activator inhibitor type 1 gene, plasminogen level and thrombosis in patients with antiphospholipid syndrome].  

Science.gov (United States)

The frequency of venous and arterial thromboses and plasminogen level were investigated in 78 patients with antiphospholipid syndrome (APS), 35 of whom with systemic lupus erythematosus (SLE+APS) and 43 - with primary APS (PAPS). The levels and genotype of plasminogen activator inhibitor type 1 (PAI-1) were determined in 45 patients with APS, of whom 21 patients with SLE + APS and 24 patients with PAPS. A control group included 10 healthy individuals without autoimmune disease signs and thromboses on period of investigation and in past history. It was shown for the first time that for one third of 67 patients with APS and thromboses high positive levels of antiphospholipid antibodies (aPL) are associated with low plasminogen levels. The levels of PAI-1 antigen measured by ELIZA method, which detects active, latent and bound with plasminogen activator PAI-1, were opposed with frequency of thromboses in APS patients. Correlation between the high and increased levels of PAI-1 and high positive aPL levels was found for one third of 43 patients with APS and thrombosis. One of the possible mechanisms of this interconnection was considered. It was shown that arterial and, to a more extent, venous thromboses are associated with the 4G/5G polymorphism of PAI-1 gene and high plasma level of the inhibitor in 79% of APS patients. At the presence of the 4G allele patients with SLE+APS had higher PAI-1 levels than patients with PAPS. The obtained results show that measuring the levels of plasminogen and PAI-1 as well as the 4G/5G polymorphism of PAI-1 gene which is associated with thromboses may have the practical significance for identification of high risk of thrombosis in APS patients. PMID:24749249

A?sina, R B; Mukhametova, L I; Ostriakova, E V; Seredavkina, N V; Patrushev, L I; Patrusheva, N L; Reshetniak, T M; Gulin, D A; Gershkovich, K B; Nasonov, E L; Varfolomeev, S D

2014-01-01

33

Downregulation of urokinase-type plasminogen activator and plasminogen activator inhibitor-1 by grape seed proanthocyanidin extract.  

Science.gov (United States)

Urokinase plasminogen activator (uPA) system, comprising of uPA, its receptor uPAR and inhibitor, type 1 plasminogen activator inhibitor (PAI-1), plays a vital role in various biological processes involving extracellular proteolysis, fibrinolysis, cell migration and proliferation. The timely occurence of these processes are essential for normal wound healing. This study examines the regulation of uPA and PAI-1 by a natural polyphenol-rich compound, grape seed extract (GSE). GSE is reported to have beneficial effects in promoting wound healing. Fibroblast cells exposed to different doses of GSE for 18hours were processed for further studies such as ELISA, RT-PCR, western blotting, fibrinolytic assay, cell surface plasmin activity assay and in vitro wound healing assay. GSE treatment caused a significant downregulation of uPA and PAI-1 expression, both at the RNA and protein levels. ELISA also revealed a dose-dependent decrease in uPA and PAI-1 activities. Functional significance of the downregulation was evident in decreased fibrinolytic activity, concomittant with decreased cell-surface plasmin activity. In vitro wound healing studies showed that GSE also retarded the migration of cells towards the wounded region. PMID:19640694

Sandra, Dhungana; Radha, Madhyastha; Harishkumar, Madhyastha; Yuichi, Nakajima; Sayuri, Omura; Masugi, Maruyama

2010-01-01

34

Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis  

Energy Technology Data Exchange (ETDEWEB)

Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T {<=} 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss {delta}m(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy E{sub eff} of 42.0 {+-} 0.9 kJ mole{sup -1}. E{sub eff} approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole{sup -1}. A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies.

Shaw, George J [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Dhamija, Ashima [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Bavani, Nazli [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Wagner, Kenneth R [Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Holland, Christy K [Department of Biomedical Engineering, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States)

2007-06-07

35

Adhesive properties conferred by the plasminogen activator of Yersinia pestis.  

Science.gov (United States)

A genomic library of Yersinia pestis EV76c created in a cosmid vector was screened for clones capable of binding type IV collagen. An unexpectedly high number of such clones was observed. One recombinant plasmid was selected for further study, and the locus controlling collagen binding was mapped by subcloning, transposon mutagenesis and exonuclease digestion. The outer-membrane protein profiles of transposon insertion mutants were correlated with phenotype to implicate a 36 kDa polypeptide in type IV collagen binding. Fine substructure restriction mapping and limited DNA sequence analysis showed the cloned locus to be identical to the locus (pla) for the plasminogen activator, previously characterized genetically and biochemically. The pla locus is resident on a 9.5 kb plasmid in wild-type Y. pestis strains. Curing of this plasmid resulted in negligible reduction in collagen-binding capacity, implying the existence of a chromosomally located determinant for collagen binding. The affinity of the plasminogen activator for collagen was relatively weak. When the cloned pla locus was introduced into E. coli, it conferred upon the cell the ability to bind to cells from a number of cell lines. Binding to glycolipids separated by thin-layer chromatography demonstrated that the receptor was a member of the globo-series of glycolipids. Since it has been reported that mutation of pla dramatically reduces virulence, we propose that this hitherto undescribed function of the gene product could contribute to the biological activities necessary for full virulence. PMID:1527508

Kienle, Z; Emödy, L; Svanborg, C; O'Toole, P W

1992-08-01

36

Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis  

International Nuclear Information System (INIS)

Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T ? 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss ?m(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy Eeff of 42.0 ± 0.9 kJ mole-1. Eeff approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole-1. A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies

37

Influence of exogenous growth factors on the expression of plasminogen activators and plasminogen activator inhibitors by cells isolated from normal and healing rabbit ligaments.  

Science.gov (United States)

In this investigation, we demonstrate that cells from normal and healing rabbit ligaments are selective in their responsiveness to various growth factors. The cells analyzed included fibroblasts isolated from the synovium, the anterior cruciate ligament, and the medial collateral ligament (midsubstance and epiligament). Fibroblasts isolated from scar tissue of medial collateral ligament that had been allowed to heal for 3 weeks also were analyzed. The addition of insulin-like growth factor-2 or transforming growth factor-beta 1 was observed to alter, in a dose-dependent manner, the expression of plasminogen activator and plasminogen activator inhibitor by connective tissue cells. However, the response to these growth factors was cell specific. Fibroblasts isolated from the midsubstance, epiligament, and scar tissue of the medial collateral ligament were responsive to these growth factors; fibroblasts isolated from the anterior cruciate ligament and synovium did not have a detectable response. The cells from the normal and healing medial collateral ligament responded to both growth factors by increasing plasminogen activator inhibitor activity. This was observed at both the protein and RNA level. In contrast, the addition of insulin-like growth factor-1 or acidic or basic fibroblast growth factor to cells derived from normal or healing ligament did not result in any detectable alteration of plasminogen activator or plasminogen activator inhibitor activity. These results are similar to those observed with an explant system and indicate that cells isolated from ligament tissue maintain their responsiveness to these growth factors in the absence of matrix. As the major effect of insulin-like growth factor-2 and transforming growth factor-beta 1 on the cells tested was to increase plasminogen activator inhibitor activity, such an alteration should diminish the activity of plasminogen activator, an enzyme capable of directly and indirectly proteolyzing matrix molecules, and thus contribute to a more anabolic environment. PMID:7520487

Murphy, P G; Hart, D A

1994-07-01

38

Transgenic chickens expressing human urokinase-type plasminogen activator.  

Science.gov (United States)

Urokinase-type plasminogen activator is a serine protease that is clinically used in humans for the treatment of thrombolytic disorders and vascular diseases such as acute ischemic stroke and acute peripheral arterial occlusion. This study explored the feasibility of using chickens as a bioreactor for producing human urokinase-type plasminogen activator (huPA). Recombinant huPA gene, under the control of a ubiquitous Rous sarcoma virus promoter, was injected into the subgerminal cavity of freshly laid chicken eggs at stage X using the replication-defective Moloney murine leukemia virus (MoMLV)-based retrovirus vectors encapsidated with VSV-G (vesicular stomatitis virus G) glycoprotein. A total of 38 chicks, out of 573 virus-injected eggs, hatched and contained the huPA gene in their various body parts. The mRNA transcript of the huPA gene was present in various organs, including blood and egg, and was germ-line transmitted to the next generation. The level of active huPA protein was 16-fold higher in the blood of the transgenic chicken than in the nontransgenic chicken (P rooster showed reduced (P < 0.05) fertility, as revealed by reduced volume of semen ejaculate, sperm concentration, and sperm viability. Taken together, our data suggest that huPA transgenic chickens could be successfully produced by the retroviral vector system. Transgenic chickens, expressing the huPA under the control of a ubiquitous promoter, may not only be used as a bioreactor for pharming of the huPA drug but also be useful for studying huPA-induced bleeding and other disorders. PMID:23960123

Lee, Sung Ho; Gupta, Mukesh Kumar; Ho, Young Tae; Kim, Teoan; Lee, Hoon Taek

2013-09-01

39

Structural and functional peculiarities of plasminogen activator inhibitor PAI-1  

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Full Text Available PAI-1, an important component of the hemostasis system, is a specific inhibitor of both urokinase type and tissue type plasminogen activators. PAI-1 belongs to the serpin family. The interaction between somatomedin-like domain of vitronectin and PAI-1 leads to stabilization of the latter. PAI-1 latency transition is related to the conformational changes in the reactive central loop. The inhibitory mechanism of PAI-1 is in accordance with the classic scheme of serpin action. PAI-1 blocks the adhesion mediated by UPA and integrins, so this inhibitor plays an important role in adhesion process and angiogenesis. An altered PAI-1level is associated with the development of cardiovascular diseases, kidney fibrosis, diabetis, cancerogenesis.

Kondratuk A. S.

2010-07-01

40

Physicochemical characteristics of magnetic microspheres containing tissue plasminogen activator  

Energy Technology Data Exchange (ETDEWEB)

As a first step toward improving the treatment of stroke, we are developing a magnetic carrier system to target tissue plasminogen activator (tPA) to a thrombosis. We report the characterization of biodegradable microspheres containing tPA and magnetic iron oxide. The resultant microspheres were superparamagnetic with a magnetization of 6.9-8.7emu/g. We encapsulated 5% tPA by mass which eluted from the microspheres to produce a solution concentration of 5.3-19.6{mu}g/mL in tPA, which exceeds the theoretical thrombolysis concentration. Although smaller microspheres will be necessary for in vivo experiments, we have shown that sufficient tPA can be encapsulated and released in a magnetic matrix.

Xie Yumei [Neurocritical Care and Acute Stroke Program, Department of Neurology and Neurosurgery, University of Chicago Pritzker School of Medicine, Chicago, IL 60637 (United States); Kaminski, Michael D. [Chemical Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Torno, Michael D. [Neurocritical Care and Acute Stroke Program, Department of Neurology and Neurosurgery, University of Chicago Pritzker School of Medicine, Chicago, IL 60637 (United States); Finck, Martha R. [Chemical Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Liu Xianqiao [Neurocritical Care and Acute Stroke Program, Department of Neurology and Neurosurgery, University of Chicago Pritzker School of Medicine, Chicago, IL 60637 (United States); Rosengart, Axel J. [Neurocritical Care and Acute Stroke Program, Department of Neurology and Neurosurgery, University of Chicago Pritzker School of Medicine, Chicago, IL 60637 (United States)]. E-mail: arosenga@neurology.bsd.uchicago.edu

2007-04-15

 
 
 
 
41

Plasminogen activator inhibitor-1 gene polymorphisms in pre-eclampsia.  

Science.gov (United States)

Pre-eclampsia (P-EC) is a multisystem disorder of pregnancy, characterized by new-onset hypertension and proteinuria. Deregulation of the coagulation cascade and hypofibrinolysis appear to play a central role in the development of this disease. After a brief review of the genetic basis of P-EC and the role of genes encoding proteins involved in coagulation, we focus on polymorphisms of the plasminogen activator inhibitor (PAI-1) gene. The most relevant association studies between PAI-1 gene polymorphisms and P-EC are reviewed. Results indicate that the 4G/4G genotype of the -675 4G/5G polymorphism represents a weak risk factor for P-EC. PMID:21370208

D'Elia, Angela V; Fabbro, Dora; Driul, Lorenza; Barillari, Giovanni; Marchesoni, Diego; Damante, Giuseppe

2011-03-01

42

[Regulation with alpha-2-antiplasmin of Glu-plasminogen activation by tissue activator on fibrin].  

Science.gov (United States)

Interaction of tissue plasminogen activator with alpha-2-antiplasmin and its influence on tissue activator binding to fibrin was studied. Alpha-2-Antiplasmin decreases the binding of tissue activator to fibrin by 20%. The inhibitor formed a complex with tissue plasminogen activator (Kd 78.2 nM) and had no effect on amidolytic activity of the activator. The tissue activator binding to alpha-2-antiplasmin decreases by 20-35% in the presence of 6-aminohexanoic acid. It indicates that not only kringle 2 of the tissue activator molecule takes part in complex formation with alpha-2-antiplasmin, but also other activator domains. Two models were proposed to explain the alpha-2-antiplasmin effect on the Glu-plasminogen activation by tissue activator on fibrin. In the first place, the inhibitor binds to fibrin in the site where the activator complex is localized. It can create steric hindrances for the proenzyme interaction with its activator on fibrin. In the second place, alpha-2-antiplasmin in a complex with tissue plasminogen activator can bring to a change in the activator conformation and a decrease of its functional activity. PMID:17100317

Hrynenko, T V; Zadorozhna, M B; Iusova, O I

2006-01-01

43

Urokinase plasminogen activator and plasminogen activator inhibitor type-1 in nonsmall-cell lung cancer: relation to prognosis and angiogenesis  

DEFF Research Database (Denmark)

BACKGROUND: Urokinase plasminogen activator (uPA) and plasminogen activator inhibitor type-1 (PAI-1) have previously been suggested as prognostic markers in nonsmall-cell lung carcinomas (NSCLC). We investigate whether uPA and PAI-1 are prognostic markers in NSCLC and whether they are related to angiogenesis. MATERIALS AND METHODS: Frozen tumour tissue from surgical specimens from 118 previously untreated patients diagnosed with NSCLC in the period 1984-1991 were investigated. All patients were treated with surgery, and no chemo- or radiotherapy was given. UPA and PAI-1 levels were assessed using a sandwich ELISA method. RESULTS: Both uPA and PAI-1 were independent of classical histopathological parameters as well as of microvessel density and vascular pattern. Using death within the first 5 years as endpoint, neither of the factors were prognostic markers in univariate analysis, however, significantly higher levels of uPA and PAI-1 were seen in tumours with an angiogenic vascular pattern. In multivariate analysis, high disease stage (P<0.0001), adenocarcinoma (P=0.007), old age (P=0.02), and presence of an angiogenic pattern (P=0.05) were identified as independent markers of death within 5 years. CONCLUSIONS: The present study investigated the prognostic role of the protein levels of uPA and PAI-1 in 118 tumour specimens from patients diagnosed with NSCLC. Neither of the factors were identified as prognostic markers when evaluated with survival as endpoint. However, in tumours previously identified as non-angiogenic we found significantly lower contents of both uPA and PAI-1 as compared to angiogenic tumours, thus we hypothesize that uPA and PAI-1 stimulate angiogenesis in NSCLC. Udgivelsesdato: 2007-Apr

Offersen, Birgitte Vrou; Pfeiffer, Per

2007-01-01

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Simvastatin suppresses dexamethasone-induced secretion of plasminogen activator inhibitor-1 in human bone marrow adipocytes  

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Abstract Background Osteonecrosis of the femoral head is a common complication of high-dose glucocorticoid treatment. Intravascular thrombosis is thought to be associated with the ischemic state of the femoral head. Plasminogen activator inhibitor-1 (PAI-1) is an adipokine, which are physiologically active substances secreted from visceral and subcutaneous adipocytes. PAI-1 suppresses fibrinolysis by binding tissue-type plasminogen activator. Several reports have described th...

Baba Hideo; Fukushima Tatsuya; Goto Hisataka; Hozumi Akira; Osaki Makoto; Sakamoto Kazutaka; Shindo Hiroyuki

2011-01-01

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Turnover of tissue plasminogen activator in normal and hepatectomized rabbits  

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The distribution, and clearance of the tissue plasminogen activator (tPA) was studied in rabbits, rats and mice. Following an intravenous injection of I-labelled tPA a large portion of the radioactive dose was rapidly accumulated in the liver. After one hour the radioactivity in the liver was less than 5 per cent of the injected dose. The highest activity was then found in the intestine, stomach and in the blood. Gel filtration of plasma taken one hour after the injection revealed that the major part (60%) of the radioactivity was present as low molecular weight metabolites or free iodine. The remaining activity was present as high molecular weight inhibitor complexes (26%) or as free tPA (15%). In order to study in vivo reactions between tPA and plasma inhibitors without hepatic interference, plasma turnover was also studied in hepatectomized rabbits. High amounts of radioactivity remained in the plasma after one hour. Gel filtration of this plasma revealed that 54 per cent of the radioactivity was bound to inhibitors, 34 per cent circulated as free tPA while a minor portion (12%) was found as free iodine or metabolites. The half-life of fibrinolytically active tPA in hepatectomized rabbits was 40 minutes compared to 2 minutes in intact rabbits. The increase in the half-life of tPA in hepatectomized rabbits also resulted in an improved thrombolytic effect after treatment with 0.5 mg tPA

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Mice deficient in plasminogen activator inhibitor-1 have improved skeletal muscle regeneration  

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journal article, "Mice deficient in plasminogen activator inhibitor-1 have improved skeletal muscle regeneration," by Timothy Koh, Scott Bryer, Augustina Pucci, and Thomas Sisson, found in the American Journal of Physiology-Cell Physiology.

PhD Timothy J. Koh (University of Illinois at Chicago Department of Movement Sciences); Scott C. Bryer (University of Illinois at Chicago Department of Movement); Augustina M. Pucci (University of Illinois at Chicago Department of Movement Sciences); Thomas S. Sisson (University of Michigan Department of Internal Medicine)

2005-07-01

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Soluble urokinase plasminogen activator receptor is associated with subclinical organ damage and cardiovascular events  

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The soluble urokinase plasminogen activator receptor (suPAR) is a plasma marker of low grade inflammation and has been associated with cardiovascular risk. We wanted to investigate whether suPAR was associated with markers of subclinical organ damage.

Sehestedt, T; Lyngbæk, S

2011-01-01

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Thrombin activatable fibrinolysis inhibitor (TAFI) affects fibrinolysis in a plasminogen activator concentration-dependent manner. Study of seven plasminogen activators in an internal clot lysis model.  

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TAFIa was shown to attenuate fibrinolysis. In our in vitro study, we investigated how the inhibitory effect of TAFIa depended on the type and concentration of the plasminogen activator (PA). We measured PA-mediated lysis times of plasma clots under conditions of maximal TAFI activation by thrombin-thrombo-modulin in the absence and presence of potato carboxypeptidase inhibitor. Seven different PAs were compared comprising both tPA-related (tPA, TNK-tPA, DSPA), bacterial PA-related (staphylokinase and APSAC) and urokinase-related (tcu-PA and k2tu-PA) PAs. The lysis times and the retardation factor were plotted against the PA concentration. The retardation factor plots were bell-shaped. At low PA concentrations, the retardation factor was low, probably due to the limited stability of TAFIa. At intermediate PA concentrations the retardation factor was maximal (3-6 depending on the PA), with TNK-tPA, APSAC and DSPA exhibiting the strongest effect. At high PA concentrations, the retardation factor was again low, possibly due to inactivation of TAFIa by plasmin or to a complete conversion of glu-plasminogen into lys-plasminogen. Using individual plasmas with a reduced plasmin inhibitor activity (plasmin inhibitor Enschede) the bell-shaped curve of the retardation factor shifted towards lower tPA and DSPA concentrations, but the height did not decrease. In conclusion, TAFIa delays the lysis of plasma clots mediated by all the plasminogen activators tested. This delay is dependent on the type and concentration of the plasminogen activator, but not on the fibrin specificity of the plasminogen activator. Furthermore, plasmin inhibitor does not play a significant role in the inhibition of plasma clot lysis by TAFI. PMID:14983222

Guimarães, Ana H C; Rijken, Dingeman C

2004-03-01

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Functional properties of the recombinant kringle-2 domain of tissue plasminogen activator produced in Escherichia coli  

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The kringle-2 domain (residues 176-262) of tissue-type plasminogen activator (t-PA) was cloned and expressed in Escherichia coli. The recombinant peptide, which concentrated in cytoplasmic inclusion bodies, was isolated, solubilized, chemically refolded, and purified by affinity chromatography on lysine-Sepharose to apparent homogeneity. [35S]Cysteine-methionine-labeled polypeptide was used to study the interactions of kringle-2 with lysine, fibrin, and plasminogen activator inhibitor-1. The kringle-2 domain bound to lysine-Sepharose and to preformed fibrin with a Kd = 104 +/- 6.2 microM (0.86 +/- 0.012 binding site) and a Kd = 4.2 +/- 1.05 microM (0.80 +/- 0.081 binding site), respectively. Competition experiments and direct binding studies showed that the kringle-2 domain is required for the formation of the ternary t-PA-plasminogen-intact fibrin complex and that the association between the t-PA kringle-2 domain and fibrin does not require plasmin degradation of fibrin and exposure of new COOH-terminal lysine residues. We also observed that kringle-2 forms a complex with highly purified guanidine-activated plasminogen activator inhibitor-1, dissociable by 0.2 M epsilon-aminocaproic acid. The kringle-2 polypeptide significantly inhibited tissue plasminogen activator/plasminogen activator inhibitor-1 interaction. The kringle-2 domain bound to plasminogen activator inhibitor-1 in a specific and saturable manner with a Kd = 0.51 +/- 0.055 microM (0.35 +/- 0.026 binding site). Therefore, the t-PA kringle-2 domain is important for the interaction of t-PA not only with fibrin, but also with plasminogen activator inhibitor-1 and thus represents a key structure in the regulation of fibrinolysis

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Targeting the urokinase plasminogen activator receptor enhances gene transfer to human airway epithelia  

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Developing gene therapy for cystic fibrosis has been hindered by limited binding and endocytosis of vectors by human airway epithelia. Here we show that the apical membrane of airway epithelia express the urokinase plasminogen activator receptor (uPAR). Urokinase plasminogen activator (uPA), or a 7-residue peptide derived from this protein (u7-peptide), bound the receptor and stimulated apical endocytosis. Both ligands enhanced gene transfer by nonspecifically bound adenovirus and adeno-assoc...

Drapkin, Paola T.; O’riordan, Catherine R.; Yi, Su Min; Chiorini, John A.; Cardella, Jonathan; Zabner, Joseph; Welsh, Michael J.

2000-01-01

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Common genetic variants in the plasminogen activation pathway are not associated with multiple sclerosis.  

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Matrix metalloproteinase 9 (MMP9) is involved in multiple sclerosis (MS) aetiology. Previously, we identified differential gene expression of plasminogen activation cascade genes in MS patients. Based on our gene expression results, we wanted to identify whether polymorphisms in the genes associated with the plasminogen pathway could predict MS risk. We genotyped 1153 trio families, 727 MS cases and 604 healthy controls for 17 polymorphisms in MMP9, plasminogen activator urokinase (PLAU), PLAU receptor (PLAUR) and serpin peptidase inhibitor/clade 2/member B2 (SERPINB2) genes. No associations were found between the 17 polymorphisms and MS. Also, gene expression levels were analysed according to genotype: no associations were observed. In conclusion despite the consistent evidence for the role of MMP9 and the plasminogen activation cascade in MS, we found no associations between genotype nor gene expression. This suggested there are other potentially modifiable factors influencing gene expression in MS. PMID:23897640

Cox, Mathew B; Bowden, Nikola A; Scott, Rodney J; Lechner-Scott, Jeannette

2014-04-01

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Human breast cancer cell-mediated bone collagen degradation requires plasminogen activation and matrix metalloproteinase activity  

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Full Text Available Abstract Background Breast cancer cells frequently metastasize to the skeleton and induce extensive bone destruction. Cancer cells produce proteinases, including matrix metalloproteinases (MMPs and the plasminogen activator system (PAS which promote invasion of extracellular matrices, but whether these proteinases degrade bone matrix is unclear. To characterize the role that breast cancer cell proteinases play in bone degradation we compared the effects of three human breast cancer cell lines, MDA-MB-231, ZR-75-1 and MCF-7 with those of a normal breast epithelial cell line, HME. The cell lines were cultured atop radiolabelled matrices of either mineralized or non-mineralized bone or type I collagen, the principal organic constituent of bone. Results The 3 breast cancer cell lines all produced significant degradation of the 3 collagenous extracellular matrices (ECMs whilst the normal breast cell line was without effect. Breast cancer cells displayed an absolute requirement for serum to dissolve collagen. Degradation of collagen was abolished in plasminogen-depleted serum and could be restored by the addition of exogenous plasminogen. Localization of plasmin activity to the cell surface was critical for the degradation process as aprotinin, but not ?2 antiplasmin, prevented collagen dissolution. During ECM degradation breast cancer cell lines expressed urokinase-type plasminogen activator (u-PA and uPA receptor, and MMPs-1, -3, -9,-13, and -14. The normal breast epithelial cell line expressed low levels of MMPs-1, and -3, uPA and uPA receptor. Inhibitors of both the PAS (aprotinin and PA inhibitor-1 and MMPs (CT1166 and tisue inhibitor of metalloproteinase blocked collagen degradation, demonstrating the requirement of both plasminogen activation and MMP activity for degradation. The activation of MMP-13 in human breast cancer cells was prevented by plasminogen activator inhibitor-1 but not by tissue inhibitor of metalloproteinase-1, suggesting that plasmin activates MMP-13 directly. Conclusions These data demonstrate that breast cancer cells dissolve type I collagen and that there is an absolute requirement for plasminogen activation and MMP activity in the degradation process.

Hill Peter A

2005-02-01

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Genome response to tissue plasminogen activator in experimental ischemic stroke  

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Full Text Available Abstract Background Tissue plasminogen activator (tPA is known to have functions beyond fibrinolysis in acute ischemic stroke, such as blood brain barrier disruption. To further delineate tPA functions in the blood, we examined the gene expression profiles induced by tPA in a rat model of ischemic stroke. Results tPA differentially expressed 929 genes in the blood of rats (p ? 0.05, fold change ? |1.2|. Genes identified had functions related to modulation of immune cells. tPA gene expression was found to be dependent on the reperfusion status of cerebral vasculature. The majority of genes regulated by tPA were different from genes regulated by ischemic stroke. Conclusions tPA modulates gene expression in the blood of rats involving immune cells in a manner that is dependent on the status of vascular reperfusion. These non-fibrinolytic activities of tPA in the blood serve to better understand tPA-related complications.

Liu Dazhi

2010-04-01

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Biochemical Importance of Glycosylation of Plasminogen Activator Inhibitor-1  

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The serpin plasminogen activator inhibitor-1 (PAI-1) is a potential target for anti-thrombotic and anti-cancer therapy. PAI-1 has 3 potential sites for N-linked glycosylation. We demonstrate here that PAI-1 expressed recombinantly or naturally by human cell lines display a heterogeneous glycosylation pattern of the sites at N209 and N265, while that at N329 is not utilised. The IC(50)-values for inactivation of PAI-1 by 4 monoclonal antibodies differed strongly between glycosylated PAI-1 and non-glycosylated PAI-1 expressed in E. coli. For 3 antibodies, an overlap of the epitopes with the glycosylation sites could be excluded as explanation for the differential reactivity. The latency transition of non-glycosylated, but not of glycosylated PAI-1, was strongly accelerated by a non-ionic detergent. The different biochemical properties of glycosylated and non-glycosylated PAI-1 depended specifically on glycosylation of either one or the other of the utilised sites. The PAI-1-binding protein vitronectin reversed the changes associated with the lack of glycosylation at one of the sites. Our results stress the importance of the source of PAI-1 when studying the mechanisms of action of PAI-1-inactivating compounds of potential clinical importance.

Gils, Ann; Pedersen, Katrine Egelund

2003-01-01

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Soluble urokinase plasminogen activator receptor during allogeneic stem cell transplantation  

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Previous studies have found that soluble urokinase plasminogen activation receptor (suPAR) increases during inflammatory and malignant illness and elevated suPAR levels may be associated with poor clinical outcome. The purpose of this study was to investigate plasma levels of suPAR during the course of allogeneic stem cell transplantation (SCT). Twenty SCT patients were included in the study. suPAR was measured by ELISA in daily taken plasma samples during the pretransplant conditioning with chemotherapy and weekly for 1 month after infusion of the graft. suPAR levels before the start of the conditioning were significantly elevated when compared to those of healthy controls. During the conditioning in particular treatment with antithymocyte globulin was associated with significantly increased suPAR levels (P = 0.012). At day +7 after infusion of the graft, suPAR levels had decreased to pretreatment levels. High suPAR levels at day 0 were associated with increased mortality (P = 0.011). The present study foundincreased suPAR levels during the conditioning in SCT patients. Further, the data indicated that increased suPAR levels may be associated with increased mortality, suggesting suPAR as a candidate for further studies as an outcome predictor in SCT.

Haastrup, E; Andersen, J

2011-01-01

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Pneumatic displacement without tissue plasminogen activator in premacular subhyaloid hemorrhage  

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Full Text Available To assess the efficacy and safety of intravitreal injection of Sulfur Hexafluoride (SF6 gas without the use of tissue Plasminogen Activator (tPA in premacular Subhyaloid Hemorrhage (SHH, 5 eyes of 5 patients with premacular SHH were enrolled. After performing paracentesis of the anterior chamber, 0.3 ml pure SF6 gas was injected through pars plana with a 30 gauge needle. Facedown position was maintained for 5 days. Subhyaloid Hemorrhage was displaced in 4/5 (80% eyes with a duration of SHH less than 2 weeks. The pre-injection visual acuity of all 5 eyes was finger counting and improved in 4/5 ( 80% eyes within 3 days to 7 days post-injection to 6/20 - 6/6. The underlying disease was hypercoagulation in 1 patient, diabetes mellitus in 2 patients, hypertension in 1 patient and unknown in 1 patient. No complications were encountered. In conclusion, SF6 gas injected into the vitreous without the use of tPA, can displace SHH if performed within 14 days of duration, and results in rapid visual recovery. This procedure is proven to be safe. (Med J Indones 2007; 16:104-7 Keywords: subhyaloid hemorrhage, pneumatic displacement, sulfur hexafluoride gas

Rumita S. Kadarisman

2007-05-01

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Regulation of epithelial sodium channels in urokinase plasminogen activator deficiency.  

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Epithelial sodium channels (ENaC) govern transepithelial salt and fluid homeostasis. ENaC contributes to polarization, apoptosis, epithelial-mesenchymal transformation, etc. Fibrinolytic proteases play a crucial role in virtually all of these processes and are elaborated by the airway epithelium. We hypothesized that urokinase-like plasminogen activator (uPA) regulates ENaC function in airway epithelial cells and tested that possibility in primary murine tracheal epithelial cells (MTE). Both basal and cAMP-activated Na(+) flow through ENaC were significantly reduced in monolayers of uPA-deficient cells. The reduction in ENaC activity was further confirmed in basolateral membrane-permeabilized cells. A decrease in the Na(+)-K(+)-ATPase activity in the basolateral membrane could contribute to the attenuation of ENaC function in intact monolayer cells. Dysfunctional fluid resolution was seen in uPA-disrupted cells. Administration of uPA and plasmin partially restores ENaC activity and fluid reabsorption by MTEs. ERK1/2, but not Akt, phosphorylation was observed in the cells and lungs of uPA-deficient mice. On the other hand, cleavage of ? ENaC is significantly depressed in the lungs of uPA knockout mice vs. those of wild-type controls. Expression of caspase 8, however, did not differ between wild-type and uPA(-/-) mice. In addition, uPA deficiency did not alter transepithelial resistance. Taken together, the mechanisms for the regulation of ENaC by uPA in MTEs include augmentation of Na(+)-K(+)-ATPase, proteolysis, and restriction of ERK1/2 phosphorylation. We demonstrate for the first time that ENaC may serve as a downstream signaling target by which uPA controls the biophysical profiles of airway fluid and epithelial function. PMID:25172911

Chen, Zaixing; Zhao, Runzhen; Zhao, Meimi; Liang, Xinrong; Bhattarai, Deepa; Dhiman, Rohan; Shetty, Sreerama; Idell, Steven; Ji, Hong-Long

2014-10-15

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Association of plasminogen activator inhibitor-1 and tissue plasminogen activator with type 2 diabetes and metabolic syndrome in Malaysian subjects  

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Full Text Available Abstract Background Increased plasma plasminogen activator inhibitor-1 (PAI-1 activity and decreased tissue plasminogen activator (tPA activity could be considered a true component of the metabolic syndrome (MetS associated with an increased risk of developing cardiovascular diseases (CVD and fibrinolytic abnormalities. The aim of this study was to investigate the association of tPA and its inhibitor PAI-1 with type 2 diabetes (T2D and MetS and interrelationship between PAI-1and tPA activities and antigens in Malaysian T2D and normal subjects. Methods The plasma activities and antigens of PAI-1 and tPA and the levels of the tPA/PAI-1 complex as well as serum insulin, parameter of the coronary risk panel and plasma glucose at fasting state were studied in 303 T2D subjects (227 with MetS and 76 without MetS, 131 normal non-diabetic non-metabolic subjects and 101 non-diabetic MetS subjects. Results The PAI-1 activity was higher in subjects with T2D with MetS (P = 9.8 × 10-19 and non-diabetic subjects with MetS (P = 3.0 × 10-15, whereas the tPA activity was lower in T2D with MetS (P = 0.003 as compare to normal subjects. Plasma tPA antigen levels were higher in subjects with T2D with MetS (P = 8.9 × 10-24, T2D without MetS (P = 1.3 × 10-13 and non-diabetic MetS subjects (P = 0.002. The activity and antigen of PAI-1 in normal subjects were related to insulin resistance (P = 2.2 × 10-4; 0.007. Additionally, the PAI-1 activity was associated with an increased waist circumference (P = 2.2 × 10-4 and decreased HDL-c (P = 0.005, whereas the tPA activity was associated with decreased FBG (P = 0.028. The highest correlation was between PAI-1 activity and its antigen (R2 = 0.695, P = 1.1 × 10-36 in diabetic subjects. The tPA activity negatively correlated with its antigen (R2 = -0.444, P = 7.7 × 10-13 in normal subjects and with the PAI-1 activity and antigen (R2 = -0.319, P = 9.9 × 10-12; R2 = -0.228, P = 3.4 × 10-6 in diabetic subjects. Conclusions PAI-1 and tPA activities and antigens were associated with diabetes and MetS parameters in Malaysian subjects.

Saif-Ali Riyadh

2011-03-01

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Beta subunits of human choriogonadotropin and ovine lutropin are biologically active.  

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Highly purified beta subunits of human choriogonadotropin and ovine lutropin were found to possess measurable steroidogenic activity in the in vitro rat Leydig cell assay. In addition, beta subunits of these two gonadotropins were able to inhibit the biological activity of human choriogonadotropin in the rat Leydig cell assay.

Moudgal, N. R.; Li, C. H.

1982-01-01

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An Active Site Water Network in the Plasminogen Activator Pla from Yersinia pestis  

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The plasminogen activator Pla from Yersinia pestis is an outer membrane protease (omptin) that is important for the virulence of plague. Here, we present the high-resolution crystal structure of wild-type, enzymatically active Pla at 1.9 {angstrom}. The structure shows a water molecule located between active site residues D84 and H208, which likely corresponds to the nucleophilic water. A number of other water molecules are present in the active site, linking residues important for enzymatic activity. The R211 sidechain in loop L4 is close to the nucleophilic water and possibly involved in the stabilization of the oxyanion intermediate. Subtle conformational changes of H208 result from the binding of lipopolysaccharide to the outside of the barrel, explaining the unusual dependence of omptins on lipopolysaccharide for activity. The Pla structure suggests a model for the interaction with plasminogen substrate and provides a more detailed understanding of the catalytic mechanism of omptin proteases.

Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert (UMASS, MED)

2010-08-13

 
 
 
 
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Plasminogen activators are involved in angiostatin generation in vivo in benign and malignant ovarian tumor cyst fluids.  

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In many tumor types, angiogenesis is the net result of pro- and anti-angiogenic mediators and correlated with metabolic activity, growth, and degree of malignancy. One of the first discovered anti-angiogenic compounds is angiostatin, a proteolytic fragment of plasminogen. The requirements for in vivo angiostatin generation have not yet been determined. We investigated the levels of plasminogen and angiostatin by western blotting and of components of the plasminogen activator complex by ELISA in cyst fluid derived from benign and malignant ovarian tumors. Fluid samples from functional ovarian follicles, dermoid cysts and endometriotic lesions were evaluated separately. When no or minimal amounts of plasminogen were present in the cyst fluids, angiostatin was generally absent as well, irrespective of plasminogen activator concentrations. When plasminogen was present, the degree of conversion of plasminogen to angiostatin was significantly correlated with the level of uPA, and, to a lesser extent, to the tPA level. However, angiostatin was also found in a number of cyst fluid samples with minimal or no plasminogen activators, suggesting the involvement of other angiostatin generating proteases in these samples. Conversely, no angiostatin was observed in a number of cyst fluid samples containing both plasminogen and plasminogen activators. The presence of an inhibitor of the enzymatic activity of uPA and/or tPA, like PAI-1, may explain this finding. Our data show that plasminogen activators are clearly involved in in vivo angiostatin formation in ovarian cysts. Most likely, however, other proteases, as well as inhibitors of plasminogen activators, are involved as well. PMID:24535412

van Tilborg, A A G; Sweep, F C G J; Geurts-Moespot, A J; Wetzels, A M M; de Waal, R M W; Westphal, J R; Massuger, L F A G

2014-04-01

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Recombinant tissue plasminogen activator in the treatment of suprachoroidal hemorrhage  

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Full Text Available Nancy Kunjukunju1, Christine R Gonzales2, William S Rodden21Ochsner Medical Center, New Orleans, Louisiana; 2Retina and Vitreous Center of Southern Oregon, Ashland, Oregon, USABackground: Suprachoroidal hemorrhages are a vision-threatening complication, and poor visual outcome is correlated with increasing hemorrhage complexity. The recommended time of surgical drainage is 10–14 days after the hemorrhage begins to liquefy. We describe a case in which recombinant tissue plasminogen activator (r-tPA, alteplase, is injected within the suprachoroidal space before surgery to assist in the drainage of an organized clot prior to liquefaction. This is a report of a technique in which r-tPA is used in the intrachoroidal space to target the organized clot of suprachoroidal hemorrhage prior to drainage.Case report: A 62-year-old male presented 12 days after retinal detachment repair with sudden ocular pain and vision loss after a Valsalva maneuver. Vision was light perception only, and intraocular pressure was 43 mmHg. Diagnosed with hyphema and suprachoroidal hemorrhage, the patient underwent surgery the following day. An injection of r-tPA 100 µg was given intracamerally, and an additional dose of r-tPA 100 µg was injected into the suprachoroidal space prior to surgery. Liquified by r-tPA, the clot was expressed through the sclerotomies. Best corrected vision in the eye eight months after the drainage procedure was 20/40.Conclusion: To the author’s knowledge, this is the first reported case in which r-tPA was successfully injected in the suprachoroidal space to liquefy and drain a suprachoroidal hemorrhage prior to natural dissolution.Keywords: tPA, suprachoroidal hemorrhage, vision loss

Nancy Kunjukunju

2011-02-01

63

Activity and expression of urokinase-type plasminogen activator and matrix metalloproteinases in human colorectal cancer  

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Full Text Available Abstract Background Matrix metalloproteinase-2 (MMP-2, matrix metalloproteinase-9 (MMP-9, and urokinase-type plasminogen activator (uPA are involved in colorectal cancer invasion and metastasis. There is still debate whether the activity of MMP-2 and MMP-9 differs between tumors located in the colon and rectum. We designed this study to determine any differences in the expression of MMP-2, MMP-9 and uPA system between colon and rectal cancer tissues. Methods Cancer tissue samples were obtained from colon carcinoma (n = 12 and rectal carcinomas (n = 10. MMP-2 and MMP-9 levels were examined using gelatin zymography and Western blotting; their endogenous inhibitors, tissue inhibitor of metalloproteinase-2 (TIMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1, were assessed by Western blotting. uPA, uPAR and PAI-1 were examined using enzyme-linked immunosorbent assay (ELISA. The activity of uPA was assessed by casein-plasminogen zymography. Results In both colon and rectal tumors, MMP-2, MMP-9 and TIMP-1 protein levels were higher than in corresponding paired normal mucosa, while TIMP-2 level in tumors was significantly lower than in normal mucosa. The enzyme activities or protein levels of MMP-2, MMP-9 and their endogenous inhibitors did not reach a statistically significant difference between colon and rectal cancer compared with their normal mucosa. In rectal tumors, there was an increased activity of uPA compared with the activity in colon tumors (P = 0.0266, however urokinase-type plasminogen activator receptor (uPAR and plasminogen activator inhibitor-1 (PAI-1 showed no significant difference between colon and rectal cancer tissues. Conclusion These findings suggest that uPA may be expressed differentially in colon and rectal cancers, however, the activities or protein levels of MMP-2, MMP-9, TIMP-1, TIMP-2, PAI-1 and uPAR are not affected by tumor location in the colon or the rectum.

Lim Kyu

2006-08-01

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Plasminogen activator activity during growth and differentiation of human HL-60 promyelocytes  

International Nuclear Information System (INIS)

The involvement of plasminogen activators (PA) of urokinase or tissue type which activate plasminogen to plasmin have been implicated in fibrinolysis, differentiation and cancer growth. In the present study, alteration of PA activity of human HL-60 promyelocytes during growth and differentiation has been investigated. HL-60 promyelocytes seeded at a density of 1 x 105 cells/ml, were examined at different densities of growth (0.2-2.0 x 106 cells/ml for PA activity, measured as plasminogen dependent hydrolysis of 125I labelled fibrin or D-Val-L-Leu-L-Lys-pNA. 125I-fibrin is hydrolyzed at a linear rate between 2-6 hours and at cell concentration of .2-1 x 106 per ml. The cellular PA activity per 106 cells at different growth densities decreases by 50% between .2-2 x 106 cells/ml. Similarly, when cells are differentiated to monocytes-macrophages by 1,25-dihydroxyvitamin D3 (as determined by NBT reduction), a decrease in PA activity is observed which parallels the degree of differentiation. The major alteration of PA activity is in the heavy membrane fraction of the differentiated cells. These studies suggest that PA levels may be important in the growth and differentiation of HL-60 cells

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Plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in sputum of allergic asthma patients.  

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Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 have been associated with asthma. The aim of this study was to evaluate concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. The study was performed on 19 HDM-AAs and 8 healthy nonatopic controls (HCs. Concentration of uPA and PAI-1 was evaluated in induced sputum supernatants using ELISA method. In HDM-AAs the median sputum concentration of uPA (128 pg/ml; 95% CI 99 to 183 pg/ml and PAI-1 (4063 pg/ml; 95%CI 3319 to 4784 pg/ml were significantly greater than in HCs (17 pg/ml; 95%CI 12 to 32 pg/ml; p<0.001 and 626 pg/ml; 95%CI 357 to 961 pg/ml; p<0.001 for uPA and PAI-1 respectively. The sputum concentration of uPA correlated with sputum total cell count (r=0.781; p=0.0001 and with logarithmically transformed exhaled nitric oxide concentration (eNO (r=0.486; p=0.035 but not with FEV1 or bronchial reactivity to histamine. On the contrary, the sputum PAI-1 concentration correlated with FEV1 (r=-0,718; p=0.0005 and bronchial reactivity to histamine expressed as log(PC20 (r=-0.824; p<0.0001 but did not correlate with sputum total cell count or eNO. The results of this study support previous observations linking PAI-1 with airway remodeling and uPA with cellular inflammation. Moreover, the observed effect of uPA seems to be independent of its fibrynolytic activity.

Sebastian Zukowski

2008-06-01

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Recombinant tissue plasminogen activator in the treatment of suprachoroidal hemorrhage  

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Nancy Kunjukunju1, Christine R Gonzales2, William S Rodden21Ochsner Medical Center, New Orleans, Louisiana; 2Retina and Vitreous Center of Southern Oregon, Ashland, Oregon, USABackground: Suprachoroidal hemorrhages are a vision-threatening complication, and poor visual outcome is correlated with increasing hemorrhage complexity. The recommended time of surgical drainage is 10–14 days after the hemorrhage begins to liquefy. We describe a case in which recombinant tissue plasminogen a...

Nancy Kunjukunju; Gonzales, Christine R.; Rodden, William S.

2011-01-01

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Design of a Standard Iranian Protocol of Intravenous Thrombolysis with Tissue Plasminogen Activator: A National Project  

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Full Text Available Standard protocols should be established for treating eligible stroke patients with tissue plasminogen activator (TPA (recommendation class I, level of evidence B. The Iranian standard protocol of intravenous thrombolysis with recombinant tissue plasminogen activator (IVTTPA is the best possible and easy to use method for performing intravenous thrombolysis in Iran. This protocol overcomes problems and limitations of IVTTPA in Iran. The protocol achieves the best selection criteria and assessment method of IVTTPA for our residents and neurologists. This protocol was provided in Persian language and could be easily downloaded from Google site by writing Thrombolysis and Iran in Persian.

Kavian Ghandehari

2013-04-01

68

Levels of plasminogen activator inhibitor type 1 and urokinase plasminogen activator receptor in non-small cell lung cancer as measured by quantitative ELISA and semiquantitative immunohistochemistry  

DEFF Research Database (Denmark)

The components of the plasminogen activation system have been reported to have prognostic impact in several cancer types, e.g. breast-, colon-, gastric- and lung cancer. Most of these studies have used quantification by enzyme-linked immunosorbent assay (ELISA) on tumour tissue extracts. However, results in non-small cell lung cancer (NSCLC) studies obtained by quantitative ELISA and semiquantitative immunohistochemistry differ. If the prognostic value of the components of the plasminogen activation system is to be exploited clinically in the future, it is important to choose an easy and valid methodology. In the present study we investigated levels of plasminogen activator inhibitor type 1 (PAI-I) and urokinase plasminogen activator receptor (uPAR), as quantitated by ELISA in tumour extracts from 64 NSCLC patients (38 squamous cell carcinomas, 26 adenocarcinomas), and compared them to staining intensity as semiquantitated by immunohistochemistry for PAI-1 and uPAR on corresponding cryostat sections. A significant association (r = 0.49), P <0.0001) was found between the PAI-1 levels measured by ELISA and semiquantitated by immunohistochemistry. No association was found for uPAR. When correlating levels of PAI-1 and uPAR determined by ELISA and immunohistochemistry, respectively, to survival status, no significant correlation was found for any of the subgroups. At present neither of the methods examined in the present study can be recommended as superior for quantitating PAI-1 and uPAR with the aim of predicting prognosis. In conclusion, a larger comparative study is needed to clarify the relationship between ELISA and immunohistochemical results, before a methodology for clinical use can be chosen in non-small cell lung cancer.

1997-01-01

69

Mechanism of enhancement by fucoidan and CNBr-fibrinogen digest of the activation of glu-plasminogen by tissue plasminogen activator.  

Science.gov (United States)

The interactions of fucoidan with human glutamic type plasminogen (Glu-Plg), porcine pancreatic elastase digested plasminogen fractions and two chain tissue plasminogen activator t-PA) were investigated using fucoidan-Sepharose affinity chromatography. The results showed a high degree of affinity between fucoidan-Sepharose and Glu-Plg or PlgK(1-3) but not with PlgK4 or mini-Plg. Fucoidan-Sepharose also showed a high affinity for t-PA, which was largely reversed by 0.002 M 6-aminohexanoic acid (6-AH). The addition of fucoidan and CNBr-fibrinogen digest (CNBr-Fbg) gave the highest enhancement of the in vitro activation of Glu-Plg by t-PA in the presence of 0.002 M 6-AH. The results of affinity chromatography and enhancement studies suggested a template mechanism, since increasing the concentrations of any one of the two cofactors reversed the enhancement. Enzyme kinetic studies, using double reciprocal plots, showed that the addition of fucoidan-6-AH increased Kcat by 7-fold without affecting Km and addition of CNBr-Fbg lowered Km by 5-fold without significantly affecting Kcat while addition of the two cofactors lowered Km by 16-fold without significantly affecting Kcat. The enhancement by fucoidan-6-AH or by CNBr-Fbg of the in vitro activation of Glu-Plg by t-PA was reversed by plasminogen activator inhibitor 1 (PAI-1). Fucoidan-Sepharose affinity chromatography revealed that the binding of PAI-1 with fucoidan may be responsible for the reversal of the enhancement by fucoidan-6-AH. PMID:11112095

Muneer, E; Bell, J; Doctor, V M

2000-01-01

70

Specific conformational changes of plasminogen induced by chloride ions, 6-aminohexanoic acid and benzamidine, but not the overall openness of plasminogen regulate, production of biologically active angiostatins.  

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The overall conformation of plasminogen depends upon the presence of anions and molecules such as AHA (6-aminohexanoic acid) and BZ (benzamidine). The purpose of the present study was to determine the effect of conformation on the initial and secondary cleavages of plasminogen to generate active angiostatins. Plasminogen was digested with the physiologically relevant neutrophil elastase in one of the four Tris/acetate buffers: buffer alone or buffer plus NaCl, AHA or BZ. The initial cleavage of Glu1-plasminogen was much slower in the tight NaCl-induced alpha-conformation, fastest in the intermediate BZ-induced beta-conformation and intermediate both in the control and in the AHA-induced open gamma-conformation. Although the buffer system determined the relative amounts of the initial cleavage products, the same four cleavage sites were utilized under all conditions. A fifth major initial cleavage within the protease domain was observed in the presence of BZ. N-terminal peptide cleavage required for angiostatin formation occurred as either the initial or the secondary cleavage. Angiostatins were generated fastest in the presence of BZ and slowest in the presence of NaCl. Both the initial and secondary cleavages were affected by the modifying agents, indicating that they influence the conformation of both Glu-plasminogen and the initial cleavage products. The angiostatins produced under the different conditions inhibited proliferation of human umbilical-vein endothelial cells. These results suggest that plasminogen conversion into active angiostatins is dependent more on the specific conformation changes induced by the various modifying reagents rather than on the overall openness of the molecule. PMID:16097950

Warejcka, Debra J; Twining, Sally S

2005-12-15

71

Plasminogen activator inhibitor type 1 regulates microglial motility and phagocytic activity  

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Full Text Available Abstract Background Plasminogen activator inhibitor type 1 (PAI-1 is the primary inhibitor of urokinase type plasminogen activators (uPA and tissue type plasminogen activators (tPA, which mediate fibrinolysis. PAI-1 is also involved in the innate immunity by regulating cell migration and phagocytosis. However, little is known about the role of PAI-1 in the central nervous system. Methods In this study, we identified PAI-1 in the culture medium of mouse mixed glial cells by liquid chromatography and tandem mass spectrometry. Secretion of PAI-1 from glial cultures was detected by ELISA and western blotting analysis. Cell migration was evaluated by in vitro scratch-wound healing assay or Boyden chamber assay and an in vivo stab wound injury model. Phagocytic activity was measured by uptake of zymosan particles. Results The levels of PAI-1 mRNA and protein expression were increased by lipopolysaccharide and interferon-? stimulation in both microglia and astrocytes. PAI-1 promoted the migration of microglial cells in culture via the low-density lipoprotein receptor-related protein (LRP 1/Janus kinase (JAK/signal transducer and activator of transcription (STAT1 axis. PAI-1 also increased microglial migration in vivo when injected into mouse brain. PAI-1-mediated microglial migration was independent of protease inhibition, because an R346A mutant of PAI-1 with impaired PA inhibitory activity also promoted microglial migration. Moreover, PAI-1 was able to modulate microglial phagocytic activity. PAI-1 inhibited microglial engulfment of zymosan particles in a vitronectin- and Toll-like receptor 2/6-dependent manner. Conclusion Our results indicate that glia-derived PAI-1 may regulate microglial migration and phagocytosis in an autocrine or paracrine manner. This may have important implications in the regulation of brain microglial activities in health and disease.

Jeon Hyejin

2012-06-01

72

Relationship between plasminogen activator inhibitor type-1 (PAI-1 gene polymorphisms and osteoporosis in Turkish women  

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Full Text Available OBJECTIVE: The development of osteoporosis is associated with several risk factors, such as genetic structures that affect bone turnover and bone mass. The impact of genetic structures on osteoporosis is not known. Plasminogen activator inhibitor type-1 regulates the bone matrix and bone balance. This study assessed the correlation between plasminogen activator inhibitor type-1 gene 4G/5G polymorphisms and osteoporosis in a population of Turkish women. METHODS: A total of 195 postmenopausal female patients who were diagnosed with osteoporosis (Group I based on bone mineral density measurements via dual-energy x-ray absorptiometry and 90 females with no osteoporosis (Group II were included in this study. Correlations between PAI-1 gene 4G/5G polymorphisms and osteoporosis were investigated through the identification of PAI-1 gene 4G/5G polymorphism genotypes using the polymerase chain reaction. RESULTS: No significant differences in the genotype and allele frequency of 4G/5G plasminogen activator inhibitor type-1 polymorphisms were observed between the two groups, and both groups exhibited the most frequently observed 4G5G genotype. CONCLUSION: No correlation between the development of osteoporosis in the female Turkish population and 4G/5G plasminogen activator inhibitor type-1 gene polymorphisms was observed.

Merih Ozgen

2012-11-01

73

Relationship between plasminogen activator inhibitor type-1 (PAI-1) gene polymorphisms and osteoporosis in Turkish women  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: The development of osteoporosis is associated with several risk factors, such as genetic structures that affect bone turnover and bone mass. The impact of genetic structures on osteoporosis is not known. Plasminogen activator inhibitor type-1 regulates the bone matrix and bone balance. Th [...] is study assessed the correlation between plasminogen activator inhibitor type-1 gene 4G/5G polymorphisms and osteoporosis in a population of Turkish women. METHODS: A total of 195 postmenopausal female patients who were diagnosed with osteoporosis (Group I) based on bone mineral density measurements via dual-energy x-ray absorptiometry and 90 females with no osteoporosis (Group II) were included in this study. Correlations between PAI-1 gene 4G/5G polymorphisms and osteoporosis were investigated through the identification of PAI-1 gene 4G/5G polymorphism genotypes using the polymerase chain reaction. RESULTS: No significant differences in the genotype and allele frequency of 4G/5G plasminogen activator inhibitor type-1 polymorphisms were observed between the two groups, and both groups exhibited the most frequently observed 4G5G genotype. CONCLUSION: No correlation between the development of osteoporosis in the female Turkish population and 4G/5G plasminogen activator inhibitor type-1 gene polymorphisms was observed.

Merih, Ozgen; Didem Turgut, Cosan; Fulya, Doganer; Ahu, Soyocak; Onur, Armagan; Hasan Veysi, Gunes; Irfan, Degirmenci; Gulsah Ogutler, Ozkara; Fezan Sahin, Mutlu.

1299-13-01

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t-plasminogen activator inhibitor-1 polymorphism in idiopathic pulmonary arterial hypertension  

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Full Text Available Aim: The aim of the present study was to identify the possible genotypic association of 3?UTR Hind III polymorphism of Plasminogen activator Inhibitor-1 (PAI-1 gene with idiopathic pulmonary arterial hypertension (IPAH. Background: IPAH is a disorder with abnormally raised mean pulmonary arterial pressure and increase in the resistance to blood flow in pulmonary artery. One of the pathological features seen is development of intraluminal thrombin deposition leading to thrombosis. Plasminogen activator inhibitor-1 is an important inhibitor of the fibrinolytic system; its up-regulation may suppress fibrinolysis and result in an increased risk of thrombosis. Method: Blood samples from 54 IPAH patients and 100 healthy voluntary donors were analyzed by PCR-RFLP method for 3?UTR Hind III polymorphism. Results and Disscussion: A significant association of Hd2 allele with the disease was observed. Raised mean level of right ventricular systolic pressure was observed in the Hd2/Hd2 genotypic patients, strengthening the role of Hd2 allele in the disease progression. Our data suggests an association of Hd2/Hd2 genotype, which may lead to the up-regulation of PAI-1 gene leading to increased levels of PAI-1, which is seen in IPAH. PAI-1 competes with plasminogen activators and hinders the normal mechanism of plasminogen activation system and leads to thrombosis and formation of plexiform lesions in the lung tissue, further strengthening its role in tissue remodeling and disease progression.

Katta Sujana

2008-01-01

75

Relationship between plasminogen activator inhibitor type-1 (PAI-1) gene polymorphisms and osteoporosis in Turkish women  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: The development of osteoporosis is associated with several risk factors, such as genetic structures that affect bone turnover and bone mass. The impact of genetic structures on osteoporosis is not known. Plasminogen activator inhibitor type-1 regulates the bone matrix and bone balance. Th [...] is study assessed the correlation between plasminogen activator inhibitor type-1 gene 4G/5G polymorphisms and osteoporosis in a population of Turkish women. METHODS: A total of 195 postmenopausal female patients who were diagnosed with osteoporosis (Group I) based on bone mineral density measurements via dual-energy x-ray absorptiometry and 90 females with no osteoporosis (Group II) were included in this study. Correlations between PAI-1 gene 4G/5G polymorphisms and osteoporosis were investigated through the identification of PAI-1 gene 4G/5G polymorphism genotypes using the polymerase chain reaction. RESULTS: No significant differences in the genotype and allele frequency of 4G/5G plasminogen activator inhibitor type-1 polymorphisms were observed between the two groups, and both groups exhibited the most frequently observed 4G5G genotype. CONCLUSION: No correlation between the development of osteoporosis in the female Turkish population and 4G/5G plasminogen activator inhibitor type-1 gene polymorphisms was observed.

Merih, Ozgen; Didem Turgut, Cosan; Fulya, Doganer; Ahu, Soyocak; Onur, Armagan; Hasan Veysi, Gunes; Irfan, Degirmenci; Gulsah Ogutler, Ozkara; Fezan Sahin, Mutlu.

76

Urokinase-type plasminogen activator supports liver repair independent of its cellular receptor  

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Full Text Available Abstract Background The urokinase-type (uPA and tissue-type (tPA plasminogen activators regulate liver matrix remodelling through the conversion of plasminogen (Plg to the active protease plasmin. Based on the efficient activation of plasminogen when uPA is bound to its receptor (uPAR and on the role of uPA in plasmin-mediated liver repair, we hypothesized that uPA requires uPAR for efficient liver repair. Methods To test this hypothesis, we administered one dose of carbon tetrachloride (CCl4 to mice with single or combined deficiencies of uPA, uPAR and tPA, and examined hepatic morphology, cellular proliferation, fibrin clearance, and hepatic proteolysis 2–14 days later. Results Absence of uPAR alone or the combined absence of uPAR and tPA had no impact on the resolution of centrilobular injury, but the loss of receptor-free uPA significantly impaired the clearance of necrotic hepatocytes up to 14 days after CCl4. In response to the injury, hepatocyte proliferation was normal in mice of all genotypes, except for uPAR-deficient (uPAR° mice, which had a reproducible but mild decrease by 33% at day 2, with an appropriate restoration of liver mass by 7 days similar to experimental controls. Immunostaining and zymographic analysis demonstrated that uPA alone promoted fibrin clearance from centrilobular regions and efficiently activated plasminogen. Conclusion uPA activates plasminogen and promotes liver matrix proteolysis during repair via a process that neither requires its receptor uPAR nor requires a contribution from its functional counterpart tPA.

Bezerra Jorge A

2006-11-01

77

[Effect of chronic epaden administration on the tissue plasminogen activator activity in rabbits].  

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The chronic oral administration of epaden (a concentrate of n-3 polyunsaturated fatty acids, n-3 PUFA) to rabbits leads to a decrease in activity of the tissue type plasminogen activator (t-PA) in the blood plasma. In order to elucidate the mechanism of this phenomenon, the epinephrine (adrenaline) stimulated t-PA release in rabbits pretreated with epaden for 4 weeks was compared to that in the control (untreated) group. The epinephrine injections led to a reliable, albeit short-time, increase in the t-PA activity in both test and control groups. Although the base activity of t-PA in the epaden-treated group was lower than that in the control group, the t-PA release in the former group was more pronounced. In addition, the t-PA production was induced by the immobilization shock model in rabbits one month after beginning of the epaden administration (animals in the control group were subject to the shock without epaden pretreatment). In this test, the t-PA release was also more intense in the epaden-treated animals. These results indicate that the dietary epaden administration per os reduces the basal t-PA level, but increases the agonist-induced plasminogen activator production. PMID:11202508

Petrukhina, G N; Kalugin, S A; Makarov, V A; Gandel', V G

2000-01-01

78

The relation between plasminogen activator inhibitor activity and disease activation in acute myeloblastic leukaemia patients.  

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Coagulation and fibrinolytic abnormalities are common in patients with acute myeloblastic leukaemia (AML) like other forms of leukaemias. In this study, we investigated if total plasminogen activator inhibitor (PAI) activity, which is believed to increase in initial diagnosis and relapse in AML patients could be accepted as a relapse criterion or not. Total of 34 AML patients and 18 healthy volunteers were included in this study. The patients' diagnosis were based on clinical criteria as well as morphological, cytochemical, immunuphenotypic examinations of peripheral blood and bone marrow specimens. Total PAI activity was measured with Dade Behring Bericrom PAI reagent in BCS system. Total PAI activity was higher than 3.5 U/ml in 11 AML patients while it was normal (0.3-3.5 U/ml) in control group (P 0.05). We found significant difference in total PAI activity between patients who have active disease and remission. In conclusion, the total PAI activity could be accepted as a relapse and an initial diagnosis criterion of AML patients during follow up. PMID:16999721

Yilmaz, M; Dagdas, S; Aki, S Z; Guler, N; Akoz, A G; Erdin, Z; Alanoglu, G; Ozet, G

2006-10-01

79

Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay.  

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Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ss-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase formulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml) and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251. Streptase was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase and Solustrep formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251 activity per vial, Streptase (75.7 +/- 5.0 units) and Streptonase (94.7 +/- 4.6 units) had the highest activity, while Unitinase (31.0 +/- 2.4 units) and Strek (32.9 +/- 3.3 units) had the weakest activity. Solustrep (53.3 +/- 2.7 units) presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated. PMID:15558196

Couto, L T; Donato, J L; de Nucci, G

2004-12-01

80

Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ß-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase form [...] ulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251™. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml) and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251™. Streptase™ was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase™ and Solustrep™ formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251™ activity per vial, Streptase™ (75.7 ± 5.0 units) and Streptonase™ (94.7 ± 4.6 units) had the highest activity, while Unitinase™ (31.0 ± 2.4 units) and Strek™ (32.9 ± 3.3 units) had the weakest activity. Solustrep™ (53.3 ± 2.7 units) presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.

L.T., Couto; J.L., Donato; G. de, Nucci.

 
 
 
 
81

Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ß-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase form [...] ulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251™. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml) and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251™. Streptase™ was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase™ and Solustrep™ formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251™ activity per vial, Streptase™ (75.7 ± 5.0 units) and Streptonase™ (94.7 ± 4.6 units) had the highest activity, while Unitinase™ (31.0 ± 2.4 units) and Strek™ (32.9 ± 3.3 units) had the weakest activity. Solustrep™ (53.3 ± 2.7 units) presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.

L.T., Couto; J.L., Donato; G. de, Nucci.

1889-18-01

82

Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay  

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Full Text Available Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ß-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase formulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251™. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251™. Streptase™ was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase™ and Solustrep™ formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251™ activity per vial, Streptase™ (75.7 ± 5.0 units and Streptonase™ (94.7 ± 4.6 units had the highest activity, while Unitinase™ (31.0 ± 2.4 units and Strek™ (32.9 ± 3.3 units had the weakest activity. Solustrep™ (53.3 ± 2.7 units presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.

L.T. Couto

2004-12-01

83

Immunoradiometric quantification of tissue plasminogen activator secreted by fetal organs. Comparison with urokinase  

International Nuclear Information System (INIS)

Explants of fetal tissues were maintained in organ cultures for 2-3 weeks and the conditioned culture media analysed for the two main plasminogen activators, tissue activator and urokinase. A new immunoradiometric method was used for determining the tissue activator. The method is based on 125I-labelled antibodies to a tissue plasminogen activator which was purified from the culture medium of an established melanoma cell line. It detected tissue activator in a concentration of 1 ?g/l or even less. Urokinase was measured with a RIA. Explants of kidney as well as thyroid gland and thymus released very substantial amounts of urokinase and smaller amounts of tissue activator. Urokinase was also detected in media conditioned by skin, spleen and pancreas. Aorta explants released only the tissue activator. The capacity of many tissues to release urokinase indicates that this is a more significant plasminogen activator in extrarenal organs than hitherto realized. The tissue activator is probably confined to vascular structures. (author)

84

Diphenyl phosphonate inhibitors for the urokinase-type plasminogen activator: optimization of the P4 position.  

Science.gov (United States)

This paper describes the structure-activity relationship in a series of tripeptidyl diphenyl phosphonate irreversible urokinase plasminogen activator (uPA) inhibitors, originally derived from an arginyltripeptide. uPA is considered an interesting target in anticancer drug design. The selectivity of these inhibitors for uPA is enhanced by the optimization of the P4 position. The most interesting compound shows an IC(50) of 5 nM, with a selectivity index of more than 3000 toward other Arg/Lys-specific proteases such as tissue-type plasminogen activator, plasmin, factor Xa, and thrombin. A synthetic strategy for the preparation of small libraries of diphenyl phosphonate analogues of capped tripeptides is described. It is shown that uPA is irreversibly inhibited, and interactions with the active site were modeled. Finally, a diparacetamol phosphonate analogue was developed to circumvent the release of cytotoxic phenol. PMID:16970403

Joossens, Jurgen; Van der Veken, Pieter; Surpateanu, Georgiana; Lambeir, Anne-Marie; El-Sayed, Ibrahim; Ali, Omar M; Augustyns, Koen; Haemers, Achiel

2006-09-21

85

Urokinase binds to a plasminogen activator inhibitor type-2-like molecule in placental microvillous membranes  

DEFF Research Database (Denmark)

Placental microvillous membranes exhibited saturable binding of urokinase-type plasminogen activator with plateau achieved by 30 min at 4 degrees C and 10 min at 37 degrees C. The binding was essentially irreversible. The capacity was about 8 pmol urokinase per mg membrane protein. Half-maximal displacement of 125I-labelled urokinase was achieved with about 1.0 nM unlabelled urokinase when using 75 micrograms membrane protein/ml. 125I-labelled urokinase did not bind when treated with diisopropylfluorophosphate to block the catalytic activity. Single-chain urokinase (prourokinase), devoid of catalytic activity, did not bind. Catalytically active tissue-type plasminogen activator did compete with 125I-labelled urokinase for binding although less efficiently than urokinase. Binding activity remained in the 100,000 x g pellet after treatment of the membranes with 3 M KCl, alkaline stripping at pH 12 or extraction by the detergent Triton X-100. The binding was essentially blocked by antibodies against plasminogen activator inhibitor-type-2 (PAI-2). Sodium dodecyl sulfate polyacrylamide gel electrophoresis of solubilized membranes with bound 125I-labelled urokinase showed that the urokinase-PAI-2 complexes largely migrated in fractions corresponding to a very large Mr although no clearly defined peaks were observed. It is suggested that PAI-2 occurs in a form anchored to syncytiotrophoblast microvilli, possibly to the cytoskeleton.

Jensen, Poul Henning; Nykjaer, A

1989-01-01

86

Secretion of extracellular hsp90? via exosomes increases cancer cell motility: a role for plasminogen activation  

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Full Text Available Abstract Background Metastasis is a multi-step process that is responsible for the majority of deaths in cancer patients. Current treatments are not effective in targeting metastasis. The molecular chaperone hsp90? is secreted from invasive cancer cells and activates MMP-2 to enhance invasiveness, required for the first step in metastasis. Methods We analyzed the morphology and motility of invasive cancer cells that were treated with exogenous exosomes in the presence or absence of hsp90?. We performed mass spectrometry and immunoprecipitation to identify plasminogen as a potential client protein of extracellular hsp90?. Plasmin activation assays and migration assays were performed to test if plasminogen is activated by extracellular hsp90? and has a role in migration. Results We found that hsp90? is secreted in exosomes in invasive cancer cells and it contributes to their invasive nature. We identified a novel interaction between hsp90? and tissue plasminogen activator that together with annexin II, also found in exosomes, activates plasmin. Extracellular hsp90? promotes plasmin activation as well as increases plasmin dependent cell motility. Conclusions Our data indicate that hsp90? is released by invasive cancer cells via exosomes and implicates hsp90? in activating plasmin, a second protease that acts in cancer cell invasion.

Chan Doug

2010-06-01

87

A kringle-containing protease with plasminogen-like activity in the basal chordate Branchiostoma belcheri.  

Science.gov (United States)

Plg (plasminogen), a member of the serine protease superfamily, is a key component constituting the fibrinolytic system, and its evolutionary origin remains unknown during the course of animal evolution. In the present study, we isolated a cDNA, designated BbPlgl, encoding a kringle-containing protease with plasminogen-like activity from the basal chordate Branchiostoma belcheri. The deduced protein, BbPlgl, consisted of 430 amino acids, which is structurally characterized by the presence of an N-terminal signal peptide of 16 amino acids, 2 kringle domains with a Lys-binding site structure, a serine protease domain with the putative tPA (tissue plasminogen activator)-cleavage site (between Arg297 and Val298), the catalytic triad His237-Asp288-Ser379 expected for protease function, and a potential N-linked glycosylation site, all characteristic of Plgs. Besides, the recombinant refolded BbPlgl was readily activated by human uPA (urokinase plasminogen activator), and exhibited Plg-like activity. BbPlgl was also able to auto-activate at neutral and alkaline pH at 4 degrees C without the addition of uPA, and the activation was accelerated by addition of human uPA. These results demonstrate that BbPlgl is a novel member of the Plg family, with a domain structure of K-K-SP (kringle-kringle-serine protease) lacking the PAN domain, pushing the evolutionary origin of Plg to the protochordate. In addition, BbPlgl displays a tissue-specific expression pattern in B. belcheri, with the most abundant expression in the hepatic caecum and hind-gut, agreeing with the notion that the hepatic caecum of amphioxus is the precursor of the vertebrate liver. PMID:19193194

Liu, Mingying; Zhang, Shicui

2009-12-01

88

Technetium-99m-labeled recombinant tissue plasminogen activator for the imaging of emboli in vivo  

International Nuclear Information System (INIS)

Tissue-type plasminogen activator (t-PA) effectively lyses activate thrombus by direct action. Recombinant t-PA (rt-PA) was labeled with technetium-99m (99mTc) to investigate the in vivo binding to fibrin clots in a feline cerebral embolism model created by insertion of an artificial fibrin clot within the carotid artery. 99mTc-rt-PA administered intravenously provided clearer imaging of clots after priming with cold rt-PA, with uptake peaking 5-10 minutes after the injection. 99mTc-labeled human serum albumin was not retained at clot sites. Systemically administered 99mTc-rt-PA binds to fibrin clots within carotid arteries in our feline model. Our results suggest that the interaction of intrinsic plasminogen activator inhibitors with extrinsically administered rt-PA may regulate the demonstration of a clot, although the precise mechanism is unclear. (author)

89

Expression of the truncated tissue plasminogen activator (K2S) gene in tobacco chloroplast.  

Science.gov (United States)

As because the plant plastid genome is highly polyploid, the transformation of chloroplasts permits the introduction of thousands of copies of foreign genes per plant cell and generates extraordinarily high levels of recombinant protein. Human tissue-type plasminogen activator is one of the most important pharmaceutical proteins involved in the breakdown of blood clots in brain and heart blood vessels. We report the introduction and expression of the truncated human tissue plasminogen activator (K2S) gene in tobacco chloroplasts. The K2S-containing vector pKCZK2S was successfully transferred to tobacco plastomes using the biolistic delivery procedure. Transplastomic plants were selected on RMOP medium containing spectinomycin (500 mg/l). In order to achieve homoplasmy, several rounds of selection and regeneration were performed. The presence, site-specific integration, homoplasmy, expression and activity assay of the transgene were confirmed in the transplastomic plants by PCR, Southern-blot, RT-PCR, SDS-PAGE, ELISA, Dot-blot, Western-blot and zymography analysis. Our results show that the tissue plasminogen activator (K2S form) protein to be expressed in tobacco chloroplasts in active form. PMID:24114696

Abdoli-Nasab, Maryam; Jalali-Javaran, Mokhtar; Cusidó, Rosa M; Palazón, Javier; Baghizadeh, Amin; Alizadeh, Houshang

2013-10-01

90

Purification and activation of caprine and canine plasminogens: Comparison with human plasminogen / Purificación y activación de los plasminógenos caprino y canino: comparación con el plasminógeno humano  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish Objetivo: unificar la purificación y activación de los plasminógenos de tres especies diferentes, a saber: humana, caprina y canina. Materiales y métodos: se usaron Lysina-Sefarosa 4B y Sefacel DEAE para las cromatografías de afinidad y de intercambio iónico, respectivamente. Se determinó la secuenc [...] ia terminal-N tanto de los plasminógenos intactos como de los degradados. Resultados: en las tres especies se identificaron bandas de 92 kDa correspondientes a los plasminógenos nativos. Se halló que sus secuencias terminales-N eran EPLDDY, DPLDDY y XXLDDY para los plasminógenos humano, caprino y canino, respectivamente. Además, se purificaron los plasminógenos degradados circulantes, cuyas secuencias terminales-N fueron, en el mismo orden, KVYLSE, RITLL Y RIYSL. Conclusión: la activación de los tres plasminógenos confirmó la formación de las bandas electroforéticas típicas de la plasmina humana correspondientes a las cadenas pesada A y liviana B, que también se identificaron en las plasminas caprina y canina. Este nuevo método de purificación facilita la comparación y el esclarecimiento de los sistemas fibrinolíticos de los mamíferos. Abstract in english Objective: To unify the purification and activation of plasminogens from three different species, namely: human, caprine and canine. Materials and methods: Lysine-Sepharose 4B and sephacel DEAE were used, for affinity and ion-exchange chromatography, respectively. The N-terminal sequence was determi [...] ned for both the intact and degraded plasminogens. Results: Bands of 92 kDa corresponding to native plasminogens were identified in the three species. Their N-terminal sequences were found to be EPLDDY, DPLDDY and XXLDDY for human, caprine and canine plasminogen, respectively. Furthermore, the degraded in vivo circulating plasminogens from the three species were purified and their N-terminal sequences were KVYLSE, RITLL and RIYLS for the human, caprine and canine, in that order. Conclusion: Activation of the three plasminogens confirmed the formation of the typical electrophoretic bands for human plasmin corresponding to the heavy A and the light B chains which were also identified in the caprine and canine plasmins. This new purification methodology facilitates the comparison and further elucidation of the fibrinolytic systems in mammals.

Omaira, Cañas Bermúdez; Alfonso, Quijano Parra; Luis Fernando, Arbeláez Ramírez.

91

Expression, purification and characterization of recombinant plasminogen activator from Gloydius brevicaudus venom in Escherichia coli.  

Science.gov (United States)

The plasminogen activator (PA) in snake venom, a serine protease, can convert plasminogen to active plasmin, indirectly causing the degradation of fibrin. It is difficult to purify sufficient snake venom PA (SV-PA) for clinical applications due to the low SV-PA content in venom. The gene encoding PA was obtained from the venom gland of Gloydius brevicaudus using RT-PCR with primers designed according to the N-terminal amino acids of G. brevicaudus venom PA (GBV-PA), was cloned into the prokaryotic expression vector pET-42a, and recombinant GBV-PA (rGBV-PA) was expressed via Isopropyl-?-d-1-Thiogalactopyranoside (IPTG) induction. Like human tissue PA, the purified renatured rGBV-PA could significantly reduce the rabbit plasma euglobulin lysis time (ELT) and prevent thrombus formation in the inferior vena cava of rats. Within the dosage range, the dosage and effects were positively correlated. PMID:23891573

Zhang, Jinhua; Meng, Wenli; Wang, Chunhua; Wu, Zhiqiang; Wu, Guotu; Xu, Yunlu

2013-09-01

92

Inhibitors of Urokinase Type Plasminogen Activator and Cytostatic Activity from Crude Plants Extracts  

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Full Text Available In view of the clear evidence that urokinase type plasminogen activator (uPA plays an important role in the processes of tumor cell metastasis, aortic aneurysm, and multiple sclerosis, it has become a target of choice for pharmacological intervention. The goal of this study was thus to determine the presence of inhibitors of uPA in plants known traditionally for their anti-tumor properties. Crude methanol extracts were prepared from the leaves of plants (14 collected from the subtropical dry forest (Guanica, Puerto Rico, and tested for the presence of inhibitors of uPA using the fibrin plate assay. The extracts that tested positive (6 were then partitioned with petroleum ether, chloroform, ethyl acetate and n-butanol, in a sequential manner. The resulting fractions were then tested again using the fibrin plate assay. Extracts from leaves of Croton lucidus (C. lucidus showed the presence of a strong uPA inhibitory activity. Serial dilutions of these C. lucidus partitions were performed to determine the uPA inhibition IC50 values. The chloroform extract showed the lowest IC50 value (3.52 µg/mL and hence contained the most potent uPA inhibitor. Further investigations revealed that the crude methanol extract and its chloroform and n-butanol partitions did not significantly inhibit closely related proteases such as the tissue type plasminogen activator (tPA and plasmin, indicating their selectivity for uPA, and hence superior potential for medicinal use with fewer side effects. In a further evaluation of their therapeutic potential for prevention of cancer metastasis, the C. lucidus extracts displayed cytostatic activity against human pancreatic carcinoma (PaCa-2 cells, as determined through an MTS assay. The cytostatic activities recorded for each of the partitions correlated with their relative uPA inhibitory activities. There are no existing reports of uPA inhibitors being present in any of the plants reported in this study.

Augusto Carvajal

2013-07-01

93

Ultrasound-triggered Release of Recombinant Tissue-type Plasminogen Activator from Echogenic Liposomes  

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Echogenic liposomes (ELIP) were developed as ultrasound-triggered targeted drug or gene delivery vehicles (Lanza et al., 1997; Huang et al., 2001). Recombinant tissue-type Plasminogen Activator (rt-PA), a thrombolytic, has been loaded into ELIP (Tiukinhoy-Laing et al., 2007). These vesicles have the potential to be used for ultrasound-enhanced thrombolysis in the treatment of acute ischemic stroke, myocardial infarction, deep vein thrombosis, or pulmonary embolus. A clinical diagnostic ultras...

Smith, Denise A. B.; Vaidya, Sampada S.; Kopechek, Jonathan A.; Huang, Shao-ling; Klegerman, Melvin E.; Mcpherson, David D.; Holland, Christy K.

2010-01-01

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Recombinant tissue-type plasminogen activator and immediate angioplasty in acute myocardial infarction.  

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BACKGROUND. The European Cooperative Study Group conducted two randomized trials in patients with suspected myocardial infarction to assess the effect of 100 mg single-chain recombinant tissue-type plasminogen activator (rt-PA, alteplase) on enzymatic infarct size, left ventricular function, morbidity and mortality relative to placebo (alteplase/placebo trial) and to assess the effect of immediate percutaneous transluminal coronary angioplasty (PTCA) in addition to alteplase (alteplase/PTCA t...

Arnold, A. E. R.; Simoons, M. L.; Bono, D. P.; Tijssen, J. G. P.; Serruys, P. W. J. C.; Verstraete, M.; Lubsen, J.; Werf, F. J. J.

1992-01-01

95

Acute myocardial infarction following intravenous tissue plasminogen activator for acute ischemic stroke: An unknown danger  

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Thrombolysis with intravenous tissue (IV) plasminogen activator (tPA) is considered for patients with acute ischemic stroke falling within the described inclusion criteria defined by The National Institute of Neurological Disorders and Stroke (NINDS) rtPA trial. Complications of IV thrombolysis with tPA are commonly related to hemorrhage, anaphylaxis, or arterial occlusion. We describe two cases of acute myocardial infarction (MI) following IV tPA infusion for acute stroke. One of the patient...

Adatia Sweta; Sanghani Sejal; Sanzgiri Prakash; Chauhan Vinay; Hastak Shirish

2010-01-01

96

Tissue type plasminogen activator regulates myeloid-cell dependent neoangiogenesis during tissue regeneration  

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Ischemia of the heart, brain, and limbs is a leading cause of morbidity and mortality worldwide. Treatment with tissue type plasminogen activator (tPA) can dissolve blood clots and can ameliorate the clinical outcome in ischemic diseases. But the underlying mechanism by which tPA improves ischemic tissue regeneration is not well understood. Bone marrow (BM)–derived myeloid cells facilitate angiogenesis during tissue regeneration. Here, we report that a serpin-resistant form of tPA by activa...

Ohki, Makiko; Ohki, Yuichi; Ishihara, Makoto; Nishida, Chiemi; Tashiro, Yoshihiko; Akiyama, Haruyo; Komiyama, Hiromitsu; Lund, Leif R.; Nitta, Atsumi; Yamada, Kiyofumi; Zhu, Zhenping; Ogawa, Hideoki; Yagita, Hideo; Okumura, Ko; Nakauchi, Hiromitsu

2010-01-01

97

Tissue plasminogen activator (alteplase) treatment for femoral artery thrombosis after cardiac catheterisation in infants and children.  

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OBJECTIVE--To determine the efficacy of fibrinolytic therapy with tissue plasminogen activator (alteplase) in infants and children with arterial thrombosis after cardiac catheterisation. DESIGN--Use of alteplase (Actilyse) in a protocol with prospective data collection. Alteplase was administered to infants and children with arterial thrombosis after cardiac catheterisation. A dose of 0.5 mg/kg/h was given continuously via a peripheral vein for the first hour followed by 0.25 mg/kg/h till clo...

Zenz, W.; Muntean, W.; Beitzke, A.; Zobel, G.; Riccabona, M.; Gamillscheg, A.

1993-01-01

98

Differing Roles for Urokinase and Tissue-Type Plasminogen Activator in Collagen-Induced Arthritis  

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The plasminogen activators, urokinase PA (u-PA) and tissue-type PA (t-PA), are believed to play important roles in inflammatory cell infiltration, fibrin deposition, and joint destruction associated with rheumatoid arthritis; however, their precise roles in such processes, particularly u-PA, have yet to be defined. Using gene-deficient mice we examined the relative contribution of the PAs to the chronic systemic collagen-induced arthritis model. Based on clinical and histological assessments,...

Cook, Andrew D.; Braine, Emma L.; Campbell, Ian K.; Hamilton, John A.

2002-01-01

99

Coordinate regulation of fibronectin matrix assembly by the plasminogen activator system and vitronectin in human osteosarcoma cells  

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Abstract Background Plasminogen activators are known to play a key role in the remodeling of bone matrix which occurs during tumor progression, bone metastasis and bone growth. Dysfunctional remodeling of bone matrix gives rise to the osteoblastic and osteolytic lesions seen in association with metastatic cancers. The molecular mechanisms responsible for the development of these lesions are not well understood. Studies were undertaken to address the role of the plasminogen ac...

McKeown-Longo Paula J; Monaghan-Benson Elizabeth; Vial Daniel

2006-01-01

100

Plasminogen activators and plasminogen activator inhibitors in connective tissues and connective tissue cells: influence of the neuropeptide substance P on expression.  

Science.gov (United States)

Tissue segments isolated from ligament, epiligament, and synovial tissues from mature female New Zealand White Rabbits were demonstrated to constitutively secrete a plasminogen activator. Several tissues were also observed to constitutively secrete a plasminogen activator inhibitor which was detected in the form of a PA-PAI complex. Heterogeneity was observed in PA and PAI activity between the different connective tissues. Heterogeneity also existed between and within the medial collateral (MCL), lateral collateral (LCL), and the anterior cruciate (ACL) ligaments. In addition to the differences in constitutive expression of PA and PAI activity, differences in the responsiveness to the neuropeptide substance P (10(-5)-10(-9) M) were also detected. This responsiveness to substance P was displayed by an increase in PA and PAI activity in the conditioned medium. The pattern of responsiveness reflected the degree of innervation of these tissues. That is, synovium and epiligament tissue were the most responsive tissues to substance P while the MCL, LCL and ACL were less responsive to the neuropeptide. Parallel results were obtained using cell culture with fibroblasts isolated from the above mentioned tissues. That is, the pattern of responsiveness was similar between cells and tissue segments. More specifically, cells isolated from both synovium and epiligament increased their both their PA (slightly) and PAI activity following exposure to substance P. This was demonstrated at both the protein and RNA level. Thus, cells within a tissue maintain their phenotype when removed from their three-dimensional matrix. These results are unique in demonstrating that normal ligament and synovial cells and tissue respond to substance P by altering the expression of PA and PAI activity. This investigation further supports the concept that innervation may be important in normal connective tissue function. PMID:7689342

Murphy, P G; Hart, D A

1993-09-01

 
 
 
 
101

Activators of plasminogen and the progression of small abdominal aortic aneurysms  

DEFF Research Database (Denmark)

The aim of this study was to examine the role of activating pathways of plasminogen in the natural history of abdominal aortic aneurysms (AAA). To fulfill this objective 70 male patients with small AAA (> 3 cm) were interviewed and examined. Their blood samples were taken at diagnosis. The patients were scanned annually for a minimum period of 1 year and a maximum of 5 years (mean 2.5 years), and referred for surgery if the AAA exceeded 5 cm in diameter. Plasma levels of urokinase-like plasminogen activator (uPA), tissue-type plasminogen activator (tPA), plasminogen-activator-inhibitor-1 (PAI-1), macrophage-inhibiting factor (MIF), transforming-growth-factor-beta1 (TGF-beta1), homocysteine, and serum levels of IgA-antibodies against Chlamydia pneumoniae (IgA-CP) and cotinine (a nicotine metabolite) were measured. The annual expansion rate correlated positively with tPA, IgA-CP, and S-cotinine; rho = 0.37 (P = 0.004), 0.28 (P = 0.01), and 0.24 (P = 0.04), while PAI-1, uPA, TGF-beta1, homocysteine, and MIF did not. S-cotinine and PAI-1 also correlated positively with tPA, rho = 0.24 (P = 0.04), and 0.33 (P = 0.005). IgA-CP did not correlate with tPA. By receiver operating characteristics (ROC) curve analysis, tPA showed to be predictive of cases expanding to above 5 cm within the first 5 years with an optimal sensitivity and specificity of 0.73 and 0.71, respectively (P = 0.015). The aortic matrix degradation in AAA may be partly caused by an activation of plasminogen by tPA, but not by uPA, which usually dominates matrix degradation. Smoking seems to be an important factor for this pathway, while the pathway of IgA-CP seems different.

Lindholt, Jes Sanddal

2006-01-01

102

Plasminogen interaction with Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The ability of Trypanosoma cruzi to interact with plasminogen, the zimogenic form of the blood serin protease plasmin, was examined. Immunohistochemistry studies revealed that both forms, epimastigotes and metacyclic trypomastigotes, were able to fix plasminogen in a lysine dependant manner. This in [...] teraction was corroborated by plasminogen activation studies. Both forms of the parasite enhanced the plasminogen activation by tissue-type plasminogen activator.The maximal enhancements obtained were 15-fold and 3.4-fold with epimastigotes and metacyclic trypomastigotes, respectively, as compared to plasminogen activation in absence of cells. Ligand-blotting analysis of proteins extracted with Triton X-114 from a microsomal fraction of epimastigotes revealed at least five soluble proteins and one hydrophobic protein able to bind plasminogen.

Laura, Almeida; Gilmer, Vanegas; Marina, Calcagno; Juan Luis, Concepción; Luisana, Avilan.

103

Mechanism of action of omega-amino acids on plasminogen activation and fibrinolysis induced by staphylokinase.  

Science.gov (United States)

Stimulation of Lys-plasminogen (Lys-Pg) and Glu-plasminogen (Glu-Pg) activation under the action of staphylokinase and Glu-Pg activation under the action of preformed plasmin-staphylokinase activator complex (Pm-STA) by low concentrations and inhibition by high concentrations of omega-amino acids (>90-140 mM) were found. Maximal stimulation of the activation was observed at concentrations of L-lysine, 6-aminohexanoic acid (6-AHA), and trans-(4-aminomethyl)cyclohexanecarboxylic acid 8.0, 2.0, and 0.8 mM, respectively. In contrast, the Lys-Pg activation rate by Pm-STA complex sharply decreased when concentrations of omega-amino acids exceeded the above-mentioned values. It was found that formation of Pm-STA complex from a mixture of equimolar concentrations of staphylokinase and Glu-Pg or Lys-Pg is stimulated by low concentrations (maximal at 10 mM) of 6-AHA. Negligible increase in the specific activities of plasmin and Pm-STA complex was detected at higher concentrations of 6-AHA (to maximal at 70 and 50 mM, respectively). Inhibitory effects of omega-amino acids on the rate of fibrinolysis induced by staphylokinase, Pm-STA complex, and plasmin were compared. It was found that inhibition of staphylokinase-induced fibrinolysis by omega-amino acids includes blocking of the reactions of Pm-STA complex formation, plasminogen activation by this complex, and lysis of fibrin by forming plasmin as a result of displacement of plasminogen and plasmin from the fibrin surface. Thus, the slow stage of Pm-STA complex formation plays an important role in the mechanism of action of omega-amino acids on Glu-Pg activation and fibrinolysis induced by staphylokinase. In addition to alpha-->beta change of Glu-Pg conformation, stimulation of Pm-STA complex formation leads to increase in Glu-Pg activation rate in the presence of low concentrations of omega-amino acids. Inhibition of Pm-STA complex formation on fibrin surface by omega-amino acids is responsible for appearance of long lag phases on curves of fibrinolysis induced by staphylokinase. PMID:17680762

Levashov, M Yu; Aisina, R B; Gershkovich, K B; Varfolomeyev, S D

2007-07-01

104

Accessibility of receptor-bound urokinase to type-1 plasminogen activator inhibitor  

International Nuclear Information System (INIS)

Urokinase plasminogen activator (uPA) interacts with a surface receptor and with specific inhibitors, such as plasminogen activator inhibitor type 1 (PAI-1). These interactions are mediated by two functionally independent domains of the molecule: the catalytic domain (at the carboxyl terminus) and the growth factor domain (at the amino terminus). The authors have now investigated whether PAI-1 can bind and inhibit receptor-bound uPA. Binding of 125I-labeled ATF (amino-terminal fragment of uPA) to human U937 monocyte-like cells can be competed for by uPA-PAI-1 complexes, but not by PAI-1 alone. Preformed 125I-labeled uPA-PAI-1 complexes can bind to uPA receptor with the same binding specificity as uPA. PAI-1 also binds to, and inhibits the activity of, receptor-bound uPA in U937 cells, as shown in U937 cells by a caseinolytic plaque assay. Plasminogen activator activity of these cells is dependent on exogenous uPA, is competed for by receptor-binding diisopropyl fluorophosphate-treated uPA, and is inhibited by the addition of PAI-1. In conclusion, in U937 cells the binding to the receptor does not shield uPA from the action of PAI-1. The possibility that in adherent cells a different localization of PAI-1 and uPA leads to protection of uPA from PAI-1 is to be considered

105

Distal hinge of plasminogen activator inhibitor-1 involves its latency transition and specificities toward serine proteases  

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Full Text Available Abstract Background The plasminogen activator inhibitor-1 (PAI-1 spontaneously converts from an inhibitory into a latent form. Specificity of PAI-1 is mainly determined by its reactive site (Arg346-Met347, which interacts with serine residue of tissue-type plasminogen activator (tPA with concomitant formation of SDS-stable complex. Other sites may also play roles in determining the specificity of PAI-1 toward serine proteases. Results To understand more about the role of distal hinge for PAI-1 specificities towards serine proteases and for its conformational transition, wild type PAI-1 and its mutants were expressed in baculovirus system. WtPAI-1 was found to be about 12 fold more active than the fibrosarcoma PAI-1. Single site mutants within the Asp355-Arg356-Pro357 segment of PAI-1 yield guanidine activatable inhibitors (a that can still form SDS stable complexes with tPA and urokinase plasminogen activator (uPA, and (b that have inhibition rate constants towards plasminogen activators which resemble those of the fibrosarcoma inhibitor. More importantly, latency conversion rate of these mutants was found to be ~3–4 fold faster than that of wtPAI-1. We also tested if Glu351 is important for serine protease specificity. The functional stability of wtPAI-1, Glu351Ala, Glu351Arg was about 18 ± 5, 90 ± 8 and 14 ± 3 minutes, respectively, which correlated well with both their corresponding specific activities (84 ± 15 U/ug, 112 ± 18 U/ug and 68 ± 9 U/ug, respectively and amount of SDS-stable complex formed with tPA after denatured by Guanidine-HCl and dialyzed against 50 mM sodium acetate at 4°C. The second-order rate constants of inhibition for uPA, plasmin and thrombin by Glu351Ala and Glu351Arg were increased about 2–10 folds compared to wtPAI-1, but there was no change for tPA. Conclusion The Asp355-Pro357 segment and Glu351 in distal hinge are involved in maintaining the inhibitory conformation of PAI-1. Glu351 is a specificity determinant of PAI-1 toward uPA, plasmin and thrombin, but not for tPA.

Shaltiel Shmuel

2003-07-01

106

Immunohistochemical localization of urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor and ?2-antiplasmin in human corneal perforation: a case report  

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Full Text Available Abstract Background Corneal ulceration leading to perforation is associated with infectious and non-infectious destructive conditions in the cornea. The fibrinolytic (plasminogen/plasmin system is considered to contribute to tissue remodeling in the wound healing process and it is believed to play an important role in proteolysis and fibrosis. To determine the localization of urokinase-type plasminogen activator (u-PA, u-PA receptor (u-PAR and ?2-antiplasmin (?2AP in the tissue of a corneal perforation, we investigated immunohistochemical expressions of u-PA, u-PAR, ?2AP, CD68, and ?-smooth muscle actin (?-SMA in a patient with corneal perforation that developed from an ulcer of no clear cause. Case presentation The patient was a 77-year-old woman who presented with a perforated corneal ulcer in her right eye. The cause of her corneal ulcer was unknown. Double immunohistochemistry was performed for the combinations of u-PA with u-PAR, CD68 or ?-SMA and ?2AP with CD68 or ?-SMA to detect the localization of u-PA and ?2AP. u-PA and u-PAR co-localization was seen in the corneal ulceration area. u-PA was mainly observed in CD68-positive cells and in some ?-SMA positive cells. On the other hand, ?2AP was not expressed in CD68-positive cells, but was expressed in ?-SMA positive cells. Conclusion We identified expression of the u-PA/u-PAR complex and ?2AP in a patient with a corneal ulcer. These two molecules are believed to play a crucial role in inflammatory cell recruitment, ECM synthesis and degradation during corneal wound healing.

Sugioka Koji

2012-11-01

107

Hormonal regulation of plasminogen activator production in porcine kidney cells (LLC-PK1)  

International Nuclear Information System (INIS)

An attempt is made to study the molecular events regulating and accompanying the hormonally modulated plasminogen activator (PA) gene expression. The model system of interest is a porcine kidney cell line, LLC-PK1, responding to calcitonin in the PA production. The plasminogen activator secreted by calcitonin treated pig kidney cells has been purified, characterized, and compared with human urinary urokinase. The purified enzyme resembles the 53 k MW components of human urokinase. PA induction in LLC-PK1 cells is sensitive to inhibition by actinomycin D, suggesting the enhanced transcription of PA-mRNA. This hypothesis was tested by measuring PA-mRNA sequences in Xenopus oocyte system which showed a 15-20 fold enhanced PA synthesis when supplied with poly (A)+ RNA from induced cells, above that obtained from uninduced cell RNA. A pleiotropic response to calcitonin in LLC-PK1 cells has been examined using two-dimensional gel electrophoresis of 35S methionine labeled polypeptides. A set of twelve intracellular polypeptides, ten induced and two repressed, has been identified in calcitonin stimulated cells. One of the induced polypeptides has been identified as plasminogen activator by two dimensional tryptic peptide mapping. Other calcitonin induced polypeptides have been identified as cytokeratins by their solubility properties and cross-reactivity with antiserum against human keratin. The results indicate that the an keratin. The results indicate that the experimental system presented here is a useful and valid one for the study of molecular events regulating and accompanying the hormonally modulated PA gene expression

108

Peroxisome Proliferator-Activated Receptor-? Ligands Alter Breast Cancer Cell Motility through Modulation of the Plasminogen Activator System.  

Science.gov (United States)

We investigated peroxisome proliferator-activated receptor-? (PPAR-?) ligands effect on cell motility and the plasminogen activator system using normal MCF-10A and malignant MCF-10CA1 cell lines. Ciglitazone reduced both wound-induced migration and chemotaxis. However, the effect was not reversed with pretreatment of cells with the PPAR-?-specific antagonist GW9662. Immunoblot analysis of conditioned media showed ciglitazone decreased plasminogen activator inhibitor-1 (PAI-1) in both cell lines; this effect was also unaltered by PPAR-? antagonism. Alternatively, treatment with the ?-6 fatty acid arachidonic acid (ArA), but not the ?-3 fatty acid docosahexanoic acid, increased both MCF-10A cell migration and cell surface uPA activity. Pretreatment with a PPAR-? antagonist reversed these effects, suggesting that ArA mediates its effect on cell motility and uPA activity through PPAR-? activation. Collectively, the data suggest PPAR-? ligands have a differential effect on normal and malignant cell migration and the plasminogen activation system, resulting from PPAR-?-dependent and PPAR-?-independent effects. PMID:22131991

Carter, Jennifer C; Church, Frank C

2011-01-01

109

Mechanism of the stimulatory effect of 6-aminohexanoic acid on plasminogen activation by streptokinase or tissue plasminogen activator: the role of chloride.  

Science.gov (United States)

Studies were conducted on the mechanism of the stimulatory effect of 6-aminohexanoic acid (6-AH) during the in vitro activation of human glutamic plasminogen (Glu-Plg) by streptokinase or by tissue plasminogen activator (t-PA) and the possible role of the addition of physiological concentrations of NaCl to the buffer solution. Enhancement by 6-AH was investigated by measuring the rate of plasmin generation using chromogenic substrate H-D-glu-phe-lys-pNA (S-2403). Control studies using plasmin showed that the addition of 6-AH at concentrations below 20 mM did not significantly affect the initial rate of the amidolytic activity of plasmin with or without the addition of NaCl to 0.05 M Tris buffer (pH 7.4). On the other hand, addition of NaCl to the buffer slowed down the initial rate of activation of Glu-Plg by streptokinase or by t-PA while increasing the percent enhancement by 6-AH when compared with the controls. The ratios of the initial rates of plasmin generation in the presence or in the absence of 6-AH were plotted against the inverse of the volume fraction of Glu-Plg, streptokinase or t-PA after serial dilutions. The results showed that when the activation reactions were performed in 50 mM of Tris buffer (pH 7.4), the enhancements by 6-AH were related to its interaction with streptokinase or t-PA, while using the same Tris buffer containing 0.6 % NaCl, the enhancements by 6-AH were related to its interaction with both Glu-Plg and streptokinase or t-PA. However, upon increasing the NaCl to 0.9%, the results showed that the enhancements by 6-AH of the activation of Glu-Plg by streptokinase or t-PA were related to its interaction with Glu-Plg. The results suggested that changes in the concentrations of NaCl play a regulatory role during the activation process. PMID:14743974

Guinn, L; Doctor, V M

2003-01-01

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Effects of Korean Red Ginseng extract on tissue plasminogen activator and plasminogen activator inhibitor-1 expression in cultured rat primary astrocytes.  

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Korean Red Ginseng (KRG) is an oriental herbal preparation obtained from Panax ginseng Meyer (Araliaceae). To expand our understanding of the action of KRG on central nervous system (CNS) function, we examined the effects of KRG on tissue plasminogen activator (tPA)/plasminogen activator inhibitor-1 (PAI-1) expression in rat primary astrocytes. KRG extract was treated in cultured rat primary astrocytes and neuron in a concentration range of 0.1 to 1.0 mg/mL and the expression of functional tPA/PAI-1 was examined by casein zymography, Western blot and reverse transcription-polymerase chain reaction. KRG extracts increased PAI-1 expression in rat primary astrocytes in a concentration dependent manner (0.1 to 1.0 mg/mL) without affecting the expression of tPA itself. Treatment of 1.0 mg/mL KRG increased PAI-1 protein expression in rat primary astrocytes to 319.3±65.9% as compared with control. The increased PAI-1 expression mediated the overall decrease in tPA activity in rat primary astrocytes. Due to the lack of PAI-1 expression in neuron, KRG did not affect tPA activity in neuron. KRG treatment induced a concentration dependent activation of PI3K, p38, ERK1/2, and JNK in rat primary astrocytes and treatment of PI3K or MAPK inhibitors such as LY294002, U0126, SB203580, and SP600125 (10 ?M each), significantly inhibited 1.0 mg/mL KRG-induced expression of PAI- 1 and down-regulation of tPA activity in rat primary astrocytes. Furthermore, compound K but not other ginsenosides such as Rb1 and Rg1 induced PAI-1 expression. KRG-induced up-regulation of PAI-1 in astrocytes may play important role in the regulation of overall tPA activity in brain, which might underlie some of the beneficial effects of KRG on CNS such as neuroprotection in ischemia and brain damaging condition as well as prevention or recovery from addiction. PMID:24235858

Ko, Hyun Myung; Joo, So Hyun; Kim, Pitna; Park, Jin Hee; Kim, Hee Jin; Bahn, Geon Ho; Kim, Hahn Young; Lee, Jongmin; Han, Seol-Heui; Shin, Chan Young; Park, Seung Hwa

2013-10-01

111

Localization of tissue plasminogen activator in the endothelium of a limited number of vessels.  

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The immunolocalization of tissue plasminogen activator (tPA) was assessed in vessels of various sizes from baboons. Femoral artery and vein, carotid artery, aorta, and sections from basal ganglia and cerebral cortex were stained for tPA and CD31, an endothelial cell-specific surface antigen. In each case, the endothelium of the large vessel stained positively for anti-CD31 but not for tPA. However, vascular structures in the adventitia corresponding to the vasa vasorum were found to be associ...

Levin, E. G.; Del Zoppo, G. J.

1994-01-01

112

Vascular protection to increase the safety of tissue plasminogen activator for stroke.  

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Thrombolytic therapy with tissue plasminogen activator (tPA) remains the most effective treatment for acute ischemic stroke, but can cause vascular damage leading to edema formation and hemorrhagic transformation (HT). In this review, we discuss how tPA contributes to the pathogenesis of vascular damage and highlight evidence to support combination therapy of tPA with pharmacological agents that are vascular protective. There is an unmet need to develop therapeutic interventions which target the underlying mechanisms of vascular damage after acute ischemic stroke in order to prevent HT and improve the safety and impact of tPA. PMID:22574982

Ishrat, Tauheed; Soliman, Sahar; Guan, Weihua; Saler, Mihaela; Fagan, Susan C

2012-01-01

113

[D-dimer and plasminogen activator of the urokinase type: personal experiences with breast cancer].  

Science.gov (United States)

Plasma values of d-dimer, a stable end product of plasmin-induced fibrinolysis, were ascertained in 128 female patients with mammary carcinoma. These patients demonstrated significantly increased d-dimers in comparison with the control group with benign mammary disease (p CA 15-3 and CEA. There was no correlation between d-dimers in the plasma and increased expression of urokinase plasminogen activator (UPA) in the tissue. Increased d-dimers in the plasma of female patients with mammary carcinoma reflect multi-factoral interactions between carcinoma growth and the haemostatic-fibrinolytic system, and may be used as tumour markers. PMID:8370485

Neises, M; Schäfer, T; Strittmatter, H J; Wischnik, A; Dettmar, P; Melchert, F

1993-07-01

114

Interconversion of Active and Inactive Conformations of Urokinase-Type Plasminogen Activator  

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The catalytic activity of serine proteases depends on a salt-bridge between the amino group of residue 16 and the side chain of Asp194. The salt-bridge stabilizes the oxyanion hole and the S1 specificity pocket of the protease. Some serine proteases exist in only partially active forms, in which the amino group of residue 16 is exposed to the solvent. Such a partially active state is assumed by a truncated form of the murine urokinase-type plasminogen activator (muPA), consisting of residues 16-243. Here we investigated the allosteric interconversion between partially active states and the fully active state. Both a monoclonal antibody (mU3) and a peptidic inhibitor (mupain-1-16) stabilize the active state. The epitope of mU3 is located in the 37- and 70-loops at a site homologous to exosite I of thrombin. The N-terminus((Ile16)) of muPA((16-243)) was less exposed upon binding of mU3 or mupain-1-16. In contrast, introduction of the mutations F40Y or E137A into muPA((16-243)) increased exposure of the N-terminus((Ile16)) and resulted in large changes in the thermodynamic parameters for mupain-1-16 binding. We conclude that the distorted state of muPA((16-243)) is conformationally ordered upon binding of ligands to the active site and upon binding of mU3 to the 37- and 70-loops. Our study establishes the 37- and 70-loops as a unique site for binding to compounds stabilizing the active state of serine proteases.

Liu, Zhuo; Kromann-Hansen, Tobias

2012-01-01

115

The nature of interactions between tissue-type plasminogen activator and platelets  

International Nuclear Information System (INIS)

To elucidate interactions responsible for inhibition of aggregation of platelets in platelet-rich plasma (PRP) harvested from whole blood preincubated with t-PA, experiments were performed with PRP and washed platelets under diverse conditions of preincubation. Both ADP and collagen induced aggregation were inhibited in PRP unless aprotinin had been added to the preincubated whole blood concomitantly with t-PA. However, in washed platelets prepared after the same exposure aggregation was intact. When washed platelets were supplemented with fibrinogen degradation products (FDPs) in concentrations simulating those in whole blood preincubated with t-PA, aggregation induced with either ADP or collagen was inhibited. Thus, the inhibition in PRP depended on generation of FDPs by activated plasminogen. The functional integrity of surface glycoprotein (GP) IIb/IIIa receptors in washed platelets was documented by autoradiography after SDS-PAGE of surface labeled GPs and by fibrinogen binding despite preincubation of the whole blood or washed platelets themselves with t-PA and plasminogen as long as exogenous calcium (greater than or equal to 0.1 microM) was present. In contrast, when calcium was absent, the platelet GP IIb/IIIa receptor was rendered susceptible to degradation by plasmin, and aggregation was inhibited by preincubation at 37 degrees C even if aprotinin was present when aggregation was being assayed. These observations reconcile disparate results in the literature from studies in vivo and in vitro by demonstrating that inhibition of aggregation of platelets in PRP and in whole blood reflects indirect effects of plasminogen activation rather than direct effects of t-PA or plasmin on the platelets themselves

116

Angiostatin generating capacity and anti-tumour effects of D-penicillamine and plasminogen activators  

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Full Text Available Abstract Background Upregulation of endogenous angiostatin levels may constitute a novel anti-angiogenic, and therefore anti-tumor therapy. In vitro, angiostatin generation is a two-step process, starting with the conversion of plasminogen to plasmin by plasminogen activators (PAs. Next, plasmin excises angiostatin from other plasmin molecules, a process requiring a donor of a free sulfhydryl group. In previous studies, it has been demonstrated that administration of PA in combination with the free sulfhydryl donor (FSD agents captopril or N-acetyl cysteine, resulted in angiostatin generation, and anti-angiogenic and anti-tumour activity in murine models. Methods In this study we have investigated the angiostatin generating capacities of several FSDs. D-penicillamine proved to be most efficient in supporting the conversion of plasminogen to angiostatin in vitro. Next, from the optimal concentrations of tPA and D-penicillamine in vitro, equivalent dosages were administered to healthy Balb/c mice to explore upregulation of circulating angiostatin levels. Finally, anti-tumor effects of treatment with tPA and D-penicillamine were determined in a human melanoma xenograft model. Results Surprisingly, we found that despite the superior angiostatin generating capacity of D-penicillamine in vitro, both in vivo angiostatin generation and anti-tumour effects of tPA/D-penicillamine treatment were impaired compared to our previous studies with tPA and captopril. Conclusion Our results indicate that selecting the most appropriate free sulfhydryl donor for anti-angiogenic therapy in a (preclinical setting should be performed by in vivo rather than by in vitro studies. We conclude that D-penicillamine is not suitable for this type of therapy.

Maass Cathy N

2006-06-01

117

Roles of tissue plasminogen activator and its inhibitor in proliferative diabetic retinopathy  

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Full Text Available AIM:To investigate the role of tissue plasminogen activator (t-PA and plasminogen activator inhibitor (PAI in proliferative diabetic retinopathy (PDR and to discuss the correlations among t-PA, PAI and vascular endothelial growth factor (VEGF expressions.METHODS: A total of 36 vitreous samples were collected from 36 patients with PDR (PDR group, and 17 vitreous samples from 17 patients with idiopathic macular hole were used as control. The concentrations of t-PA, PAI and VEGF in samples were determined by ELISA method. The correlations among t-PA, PAI and VEGF expressions were discussed.RESULTS: The concentrations of t-PA, PAI and VEGF in the PDR group were significantly higher than those in the control group (P<0.001. The t-PA and PAI expressions were highly correlated with the VEGF expression (P<0.001.CONCLUSION:In addition to VEGF, a variety of bioactive substances, such as t-PA and PAI, are involved in the pathogenesis involved in the angiogenesis of PDR. VEGF can activate t-PA expression, resulting in collagen tissue degradation and angiogenesis. VEGF may also activate the mechanism for endogenous anti-neovascularization.

Shu-Ling Wu

2014-10-01

118

Roles of tissue plasminogen activator and its inhibitor in proliferative diabetic retinopathy  

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AIM To investigate the role of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in proliferative diabetic retinopathy (PDR) and to discuss the correlations among t-PA, PAI and vascular endothelial growth factor (VEGF) expressions. METHODS A total of 36 vitreous samples were collected from 36 patients with PDR (PDR group), and 17 vitreous samples from 17 patients with idiopathic macular hole were used as control. The concentrations of t-PA, PAI and VEGF in samples were determined by ELISA method. The correlations among t-PA, PAI and VEGF expressions were discussed. RESULTS The concentrations of t-PA, PAI and VEGF in the PDR group were significantly higher than those in the control group (P<0.001). The t-PA and PAI expressions were highly correlated with the VEGF expression (P<0.001). CONCLUSION In addition to VEGF, a variety of bioactive substances, such as t-PA and PAI, are involved in the pathogenesis involved in the angiogenesis of PDR. VEGF can activate t-PA expression, resulting in collagen tissue degradation and angiogenesis. VEGF may also activate the mechanism for endogenous anti-neovascularization. PMID:25349789

Wu, Shu-Ling; Zhan, Dong-Mei; Xi, Shu-Hong; He, Xiang-Lian

2014-01-01

119

The effect of recombinant tissue plasminogen activator on MMP-2 and MMP-9 activities in vitro.  

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One of the most significant side effects during recombinant tissue plasminogen activator (rtPA) for acute stroke treatment is intracranial bleeding. Gelatinases [matrix metalloproteinase (MMP)-2 and MMP-9] are one of the agents involved in the blood-brain barrier destruction resulting in secondary bleeding into the ischemic area during stroke. Previous papers revealed that patients with high baseline MMP-9 serum level have higher risk of intracranial bleeding after thrombolytic therapy. Our objective was to evaluate rtPA influence on serum MMP-2 and MMP-9 activities in vitro. Nine sera obtained from healthy donors were applied for experiment. The commercially available rtPA (Actylise) were diluted with included solvent and additionally with phosphate-buffered saline (PBS) to get concentrations: 2, 4, 8, and 16 ?g/ml. Next, 100 ?l of serum was mixed with equal proportion with different concentrations of rtPA to obtain final rtPA concentrations: 1, 2, 4, and 8 ?g/ml. The sera together with rtPA were incubated for 1 or 2 hours at 37°C. The activity of gelatinases was estimated with zymography. The activities of MMP-9 (92 kDa) and MMP-2 (72 kDa) were increased by incubation with rtPA in a dose-dependent manner. Simultaneously, the activity of band at 200 kDa (MMP-9/MMP-9 homodimer) was decreased. The activity of gelatinases incubated for 2 hours was elevated in comparison with 1-hour incubation; however, the increase was observed even for sample without rtPA. In conclusion, this study showed that rtPA can increase the biological activity of MMP-2 and MMP-9 on posttranslational level. PMID:24963695

Golab, Piotr; Kielbus, Michal; Bielewicz, Joanna; Kurzepa, Jacek

2015-01-01

120

Activation of the zymogen to urokinase-type plasminogen activator is associated with increased interdomain flexibility  

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A key regulatory step for serine proteases of the trypsin clan is activation of the initially secreted zymogens, leading to an increase in activity by orders of magnitude. Zymogen activation occurs by cleavage of a single peptide bond near the N-terminus of the catalytic domain. Besides the catalytic domain, most serine proteases have N-terminal A-chains with independently folded domains. Little is known about how zymogen activation affects the interplay between domains. This question is investigated with urokinase-type plasminogen activator (uPA), which has an epidermal growth factor domain and a kringle domain, connected to the catalytic domain by a 15-residue linker. uPA has been implicated under several pathological conditions, and one possibility for pharmacological control is targeting the conversion of the zymogen pro-uPA to active uPA. Therefore, a small-angle X-ray scattering study of the conformations of pro-uPA and uPA in solution was performed. Structural models for the proteins were derived usingavailable atomic-resolution structures for the various domains. Active uPA was found to be flexible with a random conformation of the amino-terminal fragment domain with respect to the serine protease domain. In contrast, pro-uPA was observed to be rigid, with the amino-terminal fragment domain in a fixed position with respect to the serine protease domain. Analytical ultracentrifugation analysis supported the observed difference between pro-uPA and uPA in overall shape and size seen with small-angle X-ray scattering. Upon association of either of two monoclonal Fab (fragment antigen-binding) fragments that are directed against the catalytic domain of, respectively, pro-uPA and uPA, rigid structures were formed

Behrens, Manja A; BØtkjær, Kenneth AlrØ

2011-01-01

 
 
 
 
121

High level of urokinase plasminogen activator contributes to cholangiocarcinoma invasion and metastasis  

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Full Text Available AIM: To investigate the role of urokinase plasminogen activator (uPA in cholangiocarcinoma (CCA invasion and its correlation with clinicopathological parameters. METHODS: uPA expression in CCA tissue was determined by immunohistochemistry. The level of uPA from two CCA cell lines (HuCCA-1 and KKU-M213 and a non-cancer immortalized cholangiocyte cell line (H69 was monitored by plasminogen-gelatin zymography and western blotting, whereas that of plasminogen activator inhibitor type 1 (PAI-1 protein and uPA receptor (uPAR mRNA was monitored by western blotting and quantitative real-time reverse transcriptase polymerase chain reaction, respectively. Two independent methods were employed to suppress uPA function: a synthetic uPA inhibitor (B428 and silencing of uPA gene expression using siRNA. In vitro invasion of the uPA-disrupted cells was assessed by Matrigel-coated Transwell assay. RESULTS: The immunohistochemical study showed that 75.3% (131/174 of CCA tissues expressed uPA. High uPA expression was correlated with lymphatic invasion and metastasis of CCA patients. Plasminogen-gelatin zymography of the conditioned media and cell-surface eluates showed that both CCA cell lines, but not H69, expressed both secreted and membrane-bound forms of uPA. Although the two CCA cell lines, HuCCA-1 and KKU-M213, expressed a relatively high level of uPA and uPAR, the latter exhibited a much lower degree of in vitro invasiveness, correlating with a high expression of PAI-1 in the latter, but not in the former. Suppressing uPA function with a specific uPA inhibitor, B428, or with siRNA against uPA reduced in vitro invasiveness of KKU-M213 cells, demonstrating the requirement for uPA in the invasiveness of CCA cells. Therefore, our in vivo and in vitro studies suggest that uPA is an important requirement for the invasion process of CCA. CONCLUSION: uPA expression correlates with lymphatic invasion and metastasis in vivo and is required for CCA cell invasion in vitro, suggesting its potential as a therapeutic target.

Tuangporn Suthiphongchai

2012-01-01

122

Serum-stable RNA aptamers to urokinase-type plasminogen activator blocking receptor binding  

DEFF Research Database (Denmark)

The serine proteinase urokinase-type plasminogen activator (uPA) is widely recognized as a potential target for anticancer therapy. Its association with cell surfaces through the uPA receptor (uPAR) is central to its function and plays an important role in cancer invasion and metastasis. In the current study, we used systematic evolution of ligands by exponential enrichment (SELEX) to select serum-stable 2'-fluoro-pyrimidine-modified RNA aptamers specifically targeting human uPA and blocking the interaction to its receptor at low nanomolar concentrations. In agreement with the inhibitory function of the aptamers, binding was found to be dependent on the presence of the growth factor domain of uPA, which mediates uPAR binding. One of the most potent uPA aptamers, upanap-12, was analyzed in more detail and could be reduced significantly in size without severe loss of its inhibitory activity. Finally, we show that the uPA-scavenging effect of the aptamers can reduce uPAR-dependent endocytosis of the uPA-PAI-1 complex and cell-surface associated plasminogen activation in cell culture experiments. uPA-scavenging 2'-fluoro-pyrimidine-modified RNA aptamers represent a novel promising principle for interfering with the pathological functions of the uPA system.

Dupont, Daniel Miotto; Madsen, Jeppe Buur

2010-01-01

123

Plasminogen activator inhibitor-1 polymers, induced by inactivating amphipathic organochemical ligands.  

DEFF Research Database (Denmark)

Negatively charged organochemical inactivators of the anti-proteolytic activity of plasminogen activator inhibitor-1 (PAI-1) convert it to inactive polymers. As investigated by native gel electrophoresis, the size of the PAI-1 polymers ranged from dimers to multimers of more than 20 units. As compared with native PAI-1, the polymers exhibited an increased resistance to temperature-induced unfolding. Polymerization was associated with specific changes in patterns of digestion with non-target proteases. During incubation with urokinase-type plasminogen activator, the polymers were slowly converted to reactive centre-cleaved monomers, indicating substrate behaviour of the terminal PAI-1 molecules in the polymers. A quadruple mutant of PAI-1 with a retarded rate of latency transition also had a retarded rate of polymerization. Studying a number of serpins by native gel electrophoresis, ligand-induced polymerization was observed only with PAI-1 and heparin cofactor II, which were also able to copolymerize. On the basis of these results, we suggest that the binding of ligands in a specific region of PAI-1 leads to so-called loop-sheet polymerization, in which the reactive centre loop of one molecule binds to beta-sheet A in another molecule. Induction of serpin polymerization by small organochemical ligands is a novel finding and is of protein chemical interest in relation to pathological protein polymerization in general. Udgivelsesdato: 2003-Jun-15

Pedersen, Katrine E; Einholm, Anja P

2003-01-01

124

Targeting the autolysis loop of urokinase-type plasminogen activator with conformation-specific monoclonal antibodies  

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Tight regulation of serine proteases is essential for their physiological function, and unbalanced states of protease activity have been implicated in a variety of human diseases. One key example is the presence of uPA (urokinase-type plasminogen activator) in different human cancer types, with high levels correlating with a poor prognosis. This observation has stimulated efforts into finding new principles for intervening with uPA's activity. In the present study we characterize the so-called autolysis loop in the catalytic domain of uPA as a potential inhibitory target. This loop was found to harbour the epitopes for three conformation-specific monoclonal antibodies, two with a preference for the zymogen form pro-uPA, and one with a preference for active uPA. All three antibodies were shown to have overlapping epitopes, with three common residues being crucial for all three antibodies, demonstrating a direct link between conformational changes of the autolysis loop and the creation of a catalytically matureactive site. All three antibodies are potent inhibitors of uPA activity, the two pro-uPA-specific ones by inhibiting conversion of pro-uPA to active uPA and the active uPA-specific antibody by shielding the access of plasminogen to the active site. Furthermore, using immunofluorescence, the conformation-specific antibodies mAb-112 and mAb-12E6B10 enabled us to selectively stain pro-uPA or active uPA on the surface of cultured cells. Moreover, in various independent model systems, the antibodies inhibited tumour cell invasion and dissemination, providing evidence for the feasibility of pharmaceutical intervention with serine protease activity by targeting surface loops that undergo conformational changes during zymogen activation.

BØtkjær, Kenneth AlrØ; Fogh, Sarah

2011-01-01

125

Detection of deep venous thrombosis with indium 111-labelled monoclonal antibody against tissue plasminogen activator  

International Nuclear Information System (INIS)

The administration of a radiolabelled monoclonal antibody against tissue plasminogen activator allows detection of areas with increased fibrinolytic activity, i.e. those with an active thrombotic lesion. Eight patients with phlebographically verified deep venous thrombosis were examined. At the time of immunoscintigraphy study they were examined receiving anticoagulant therapy. Some 75-85 MBq 111In-labelled antibody were injected, and scintigrams were obtained after 30 min and after 24 h. The precise site of the thrombus could not be visualized after 30 min due to high background activity, whereas after 24 h it was detectable in all patients. The thrombus/background ratios achieved are twice as high as those observed in a human antifibrin antibody study. These preliminary data suggest a high sensitivity of our PA-specific antibody for the detection of active deep venous thrombosis in man, and our antibody seems to offer theoretical advantages over both platelet and fibrin-specific antibodies. (orig.)

126

Urokinase plasminogen activator receptor on invasive cancer cells: A prognostic factor in distal gastric adenocarcinoma  

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Gastric cancer is the second cancer causing death worldwide. The five-year survival for this malignancy is below 25% and few parameters have shown an impact on the prognosis of the disease. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micrometastasis and poor prognosis. Using immunohistochemistry, the prognostic significance of uPAR was evaluated in tissue samples from a retrospective series of 95 gastric cancer patients. uPAR was expressed by neoplastic cells, macrophages, myofibroblasts and neutrophils in both intestinal and diffuse subtypes. No association was demonstrated between the expression of uPAR on cancer cells and histological subtype (p = 0.64) or TNM stage (p = 0.75). Univariate analysis revealed a significant association between the expression of uPAR on tumor cells in the peripheral invasion zone and overall survival of gastric cancer patients (HR = 2.16; 95% CI: 1.13-4.14; p = 0.02). Multivariate analysis showed that uPAR immunoreactivity in cancer cells at the invasive front is an independent prognostic factor for overall survival in gastric cancer (HR = 2.39; 95% CI: 1.22-4.69; p = 0.011). In consequence, scoring of uPAR-positive cancer cells may be a direct measure for the invasive potential of gastric adenocarcinomas.

Alpizar, Warner Enrique Alpizar; Christensen, Ib Jarle

2012-01-01

127

The Role of Plasminogen Activator Inhibitor-1 in the Metabolic Syndrome and Its Regulation  

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Full Text Available Obesity is a major risk factor for cardiovascular disease (CVD. Lipid abnormalities, hypertension, impaired glucose tolerance or diabetes, are cardiovascular risk factors that are frequently present in patients with obesity. Haemostatic and fibrinolytic disturbances are also considered to be important risk factors for CVD hence, a potential link between CVD, obesity and the metabolic syndrome arises. Regulation of the fibrinolytic system can occur at the level of plasminogen activators and plasminogen activator inhibitor-1 (PAI-1. PAI-1, a glycoprotein, is one of the most important inhibitors of fibrinolysis. Regulation of this serine protease inhibitor may have a beneficial effect on other conditions associated with the metabolic syndrome. Human adipose tissue is a source of PAI-1. PAI-1 production may in turn be controlled by a number of hormones and cytokines which are secreted by adipose tissue in addition to dietary factors. In this review we summarise the current knowledge regarding the role of altered fibrinolytic function in obesity, CVD and hence the metabolic syndrome. Regulatory factors including different dietary components, weight loss and dietary intervention will also be discussed.

Martha Phelan

2014-07-01

128

Recombinant tissue plasminogen activator enhances microglial cell recruitment after stroke in mice.  

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The effect of recombinant human tissue plasminogen activator (rtPA) on neuroinflammation after stroke remains largely unknown. Here, we tested the effect of rtPA on expression of cellular adhesion molecules, chemokines, and cytokines, and compared those with levels of inflammatory cell recruitment, brain injury, and mortality over 3 days after transient middle cerebral artery occlusion (MCAO) in mice. Mortality was dramatically increased after rtPA treatment compared with saline treatment during the first day of reperfusion. Among the animals that survived, rtPA significantly increased CCL3 expression, microglia recruitment, and cerebral infarction 6 hours after MCAO. In contrast, the extent of neutrophils and macrophages infiltration in the brain was similar in both saline- and rtPA-treated animals. Recombinant human tissue plasminogen activator induced Il1b and Tnf expression, 6 and 72 hours after MCAO, respectively, and dramatically reduced interleukin 6 (IL-6) level 24 hours after reperfusion. A dose response study confirmed the effect of rtPA on CCL3 and Il1b expressions. The effect was similar at the doses of 1 and 10 mg/kg. In conclusion, we report for the first time that rtPA amplified microglia recruitment early after stroke in association with a rapid CCL3 production. This early response may take part in the higher susceptibility of rtPA-treated animals to reperfusion injury. PMID:24473480

Lenglet, Sébastien; Montecucco, Fabrizio; Denes, Adam; Coutts, Graham; Pinteaux, Emmanuel; Mach, François; Schaller, Karl; Gasche, Yvan; Copin, Jean-Christophe

2014-05-01

129

Regulation of programmed cell death by plasminogen activator inhibitor type 1 (PAI-1)  

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Et forhøjet niveau af plasminogen activator inhibitor-1 (PAI-1) er forbundet med dårlig prognose i kræft. En forklaring på det forhøjede niveau af PAI-1 kunne være et beskyttende respons på en forøget proteolytisk aktivitet forårsaget af et forhøjet niveau af urokinase-type plasminogen activator (uPA) som er observeret i tumorer. En lang række af videnskabelige arbejder peger derimod i retning af at PAI-1 i sig selv bidrager til sydomsudviklingen. PAI-1 er blevet rapporteret at ahve indvikning på de fleste basale cellulære mekanismer herunder, celle-adhæsion, celle-migration, celle-proliferation og et stigernde antal af videnskabelige artikler indikere at PAI-1 også kan regulere programmeret celle-død (PCD) in kræft-celler og normale celler. I en række videnskabelige arbejder indikere, at PAI-1 can hæmme PCD gennem PAI-1's pro-adhæsive/anti-proteolytiske egenskab, hvorimod andre videnskabelige arbejder indikere at PAI-1 enten kan inducere PCD gennem PAI-1's anti-adhæsive egenskab.

Lademann, Ulrik Axel; RØmer, Maria Unni Koefoed

2008-01-01

130

Suppression of ovine lymphocyte activation by Teladorsagia circumcincta larval excretory-secretory products.  

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Teladorsagia circumcincta is an important pathogenic nematode of sheep. It has been demonstrated previously that stimulation of murine T lymphocytes with excretory-secretory (ES) products derived from fourth stage larvae of T. circumcincta (Tci-L4-ES) results in de novo expression of Foxp3, a transcription factor intimately involved in regulatory T cell function. In the current study, Foxp3? T cell responses in the abomasum and the effects of Tci-L4-ES on ovine peripheral blood mononuclear cells (PBMC) following T. circumcincta infection were investigated. T. circumcincta infection resulted in a significant increase in numbers of abomasal Foxp3? T cells, but not an increase in the proportion of T cells expressing Foxp3. Unlike in mice, Tci-L4-ES was incapable of inducing T cell Foxp3 expression but instead suppressed mitogen-induced and antigen-specific activation and proliferation of ovine PBMC in vitro. This effect was heat labile, suggesting that it is mediated by protein(s). Suppression was associated with up-regulation of interleukin-10 (IL-10) mRNA, and specific monoclonal antibody neutralisation of IL-10 resulted in a 50% reduction in suppression, indicating involvement of the IL-10 signaling pathway. Suppression was significantly reduced in PBMC isolated from T. circumcincta infected vs. helminth-naïve lambs, and this reduction in suppression was associated with an increase in Tci-L4-ES antigen-specific T cells within the PBMC. In conclusion, we have identified a mechanism by which T. circumcincta may modulate the host adaptive immune response, potentially assisting survival of the parasite within the host. However, the impact of Tci-L4-ES-mediated lymphocyte suppression during T. circumcincta infection remains to be determined. PMID:23964850

McNeilly, Tom N; Rocchi, Mara; Bartley, Yvonne; Brown, Jeremy K; Frew, David; Longhi, Cassandra; McLean, Louise; McIntyre, Jenni; Nisbet, Alasdair J; Wattegedera, Sean; Huntley, John F; Matthews, Jacqueline B

2013-01-01

131

Long-term stability of recombinant tissue plasminogen activator at -80 C  

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Full Text Available Abstract Background Recombinant tissue plasminogen activator (tPA is a thrombolytic widely used clinically in the treatment of acute thrombotic disease such as ischemic stroke, myocardial infarction, and deep venous thrombosis. This has led to much interest in tPA based lytic therapies leading to laboratory based in-vitro and in-vivo investigations using this drug. However, tPA reconstituted in solution exhibits full activity for only 6–8 hours, according to the manufacturer. Therefore, methods to store reconstituted tPA for long durations while maintaining activity would be of assistance to laboratories using this enzyme. Findings In this work, the enzymatic activity of tPA stored at -80 C over time was measured, using an ELISA technique that measured the amount of active tPA bound to plasminogen activator inhibitor 1 (PAI-1 in a given sample. Sample of tPA solution mixed to a concentration of 1 (mg/ml were stored in cryogenic vials at -80 C for up to 7 years. For a given sample, aliquots were assayed for tPA activity, and compared with a tPA standard to determine relative enzymatic activity. Results are reported as means with standard errors, and 12 measurements were performed for each sample age. Conclusion There was no decrease in tPA activity for samples stored up to 7 years. Such cryogenic storage is a viable method for the preservation of tPA solution for laboratory investigations of tPA-based lytic therapies.

Sperling Matthew

2009-06-01

132

Stability of Recombinant Tissue Plasminogen Activator at ?30 °C over One Year  

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Full Text Available Recombinant tissue plasminogen activator (rt-PA is used to restore patency and avoid inadvertent removal of peripheral and central venous catheters. rt-PA was reconstituted (1 mg/mL then cryopreserved at ?30 °C for 1, 2, 3, 6, 8, and 12 months and, then its stability was determined. After cryopreservation for one and two months, rt-PA kept more than 95% of its activity compared to standard samples, while cryopreservation for three months caused 8% loss of activity. However, after cryopreservation for six months or more, rt-PA retained only 87.5% or less activity compared to standard samples. Therefore, it is recommended that reconstituted rt-PA be cryopreserved at ?30 °C for a maximum period of three months.

Abdulmalik Alkatheri

2013-01-01

133

HMGB-1 promotes fibrinolysis and reduces neurotoxicity mediated by tissue plasminogen activator.  

Science.gov (United States)

Owing to its ability to generate the clot-dissolving protease plasmin, tissue plasminogen activator (tPA) is the only approved drug for the acute treatment of ischemic stroke. However, tPA also promotes hemorrhagic transformation and excitotoxic events. High mobility group box-1 protein (HMGB-1) is a non-histone transcription factor and a pro-inflammatory cytokine, which has also been shown to bind to both tPA and plasminogen. We thus investigated the cellular and molecular effects through which HMGB-1 could influence the vascular and parenchymal effects of tPA during ischemia. We demonstrate that HMGB-1 not only increases clot lysis by tPA, but also reduces the passage of vascular tPA across the blood-brain barrier, as well as tPA-driven leakage of the blood-brain barrier. In addition, HMGB-1 prevents the pro-neurotoxic effect of tPA, by blocking its interaction with N-methyl-D-aspartate (NMDA) receptors and the attendant potentiation of NMDA-induced neuronal Ca²? influx. In conclusion, we show in vitro that HMGB-1 can promote the beneficial effects of tPA while counteracting its deleterious properties. We suggest that derivatives of HMGB-1, devoid of pro-inflammatory properties, could be used as adjunctive therapies to improve the overall benefit of tPA-mediated thrombolysis following stroke. PMID:21610098

Roussel, Benoit D; Mysiorek, Caroline; Rouhiainen, Ari; Jullienne, Amandine; Parcq, Jerome; Hommet, Yannick; Culot, Maxime; Berezowski, Vincent; Cecchelli, Romeo; Rauvala, Heikki; Vivien, Denis; Ali, Carine

2011-06-15

134

Expression of plasminogen activators in preimplantation rat embryos developed in vivo and in vitro  

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Full Text Available Abstract Background Embryo implantation plays a major role in embryogenesis and the outcome of pregnancy. Plasminogen activators (PAs have been implicated in mammalian fertilization, early stages of development and embryo implantation. The invasion of trophoblast cells into the endometrium during the implantation process can be blocked by inhibitors of serine proteases, illustrating the role of these enzymes in the invasion process. As in vitro developing embryos resulted in lower implantation rate than those developed in vivo we assume that a reduced PAs activity may lead to it. There is hardly any information regarding qualitative or quantitative differences in expression of PAs in preimplantation embryos, or comparisons between in vivo and in vitro developed embryos. The purpose of this study was to assess the expression of urokinase type (uPA and tissue type (tPA plasminogen activators in in vivo and in vitro preimplantation development in rat embryos using immunofluorescence confocal microscopy and computerized image analysis. Methods Zygotes, 2-cell, 4-cell, 8-cell, morula and blastocyst stages of development were flushed from the reproductive tract (control groups of Wistar rats. Zygotes were flushed and grown in vitro to the above mentioned developmental stages and comprised the experimental groups. Immunofluorescence microscopy and computerized image analysis were used to evaluate both qualitative (localization and quantitative expression of plasminogen activators. Results uPA and tPA were found to be expressed in rat embryos throughout their preimplantation development, both in vivo and in vitro. While uPA was localized mainly in the cell cytoplasm, the tPA was detected mainly on cell surface and in the perivitelline space. In blastocysts, both in vivo and in vitro, uPA and tPA were localized in the trophectoderm cells. Total uPA content per embryo was higher in the in vivo as compared with the in vitro developed embryos at all stages measured. Blastocyst uPA content was significantly low as compared with the four-cell, eight-cell, and morula stages. Total tPA content was higher in embryos developed in vivo than those developed in vitro except for the 4-cell and 8-cell stages. Conclusion In vitro embryo development leads to lower PAs expression in a stage dependent manner as compared with in vivo developing controls. The enzymes studied vary probably in the ratio of their active and inactive forms as there is no correlation between their content and the activity observed in our previous study. The localization of both PAs in the blastocysts' trophectoderm supports the assumption that PAs plays a role in the implantation process in rats.

Har-Vardi Iris

2005-02-01

135

Differential regulation of plasminogen activation in normal keratinocytes and SCC-4 cells by fibroblasts.  

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The plasminogen activator (PA)/plasmin system is thought to be involved in processes such as tumor invasion and wound healing, during which epithelial and mesenchymal cells come close together. However, information on regulation of the PA/plasmin system during epithelial-mesenchymal interactions is scarce. Therefore, we examined the in vitro modulation of the production and activity of the components of the PA/plasmin system in squamous carcinoma cells (SCC-4) and normal human keratinocytes in relation to cell density and the presence or absence of fibroblasts (3T3 cells). There was an inverse relation between cell density and mRNA expression for urokinase-type plasminogen activator (u-PA) and u-PA receptor in both SCC-4 cells and keratinocytes. In addition, such a relation was found for plasminogen activator inhibitor types 1 (PAI-1) and 2 (PAI-2) in SCC-4 monocultures, but not in keratinocyte monocultures. In contrast to monocultures, variation of cell density did not affect the mRNA expression of the components of the PA/plasmin system in cocultures of SCC-4 cells or keratinocytes with 3T3 cells. However, the relative expression of mRNAs in co-cultures was clearly different from that in monocultures, especially at low cell density. For most of the components of the PA/plasmin system, a decrease in mRNA expression and u-PA receptor protein was observed at most cell densities, whereas for PAI-1 only in keratinocytes a marked increase was documented. Zymography of supernatants revealed that the levels of both free u-PA and PA-PAI were increased in SCC-4/3T3 co-cultures, whereas in keratinocytes/3T3 co-cultures, only levels of the PA-PAI complex were increased, while the amount of free u-PA activity decreased. This occurred despite the increase u-PA immunoreactivity and was probably caused by the markedly elevated levels of immunoreactive PAI-1. The results of the present study reveal that the production and synthesis of various components of the PA/plasmin system in keratinocytes and SCC-4 cells depend on the density of epithelial cells and are modulated by fibroblasts, probably through a direct cell-cell or cell-matrix contact. Fibroblast-induced modulations are similar in keratinocytes and SCC-4 cells except for the regulation of PAI-1, which is markedly enhanced only in keratinocytes. This suggests that the modulation of PA activity in the direct microenvironment may be different under physiologic and pathologic conditions. PMID:7861005

Boxman, I L; Quax, P H; Löwik, C W; Papapoulos, S E; Verheijen, J; Ponec, M

1995-03-01

136

Production of longer acting tissue plasminogen activator of humans in milk of transgenic mice.  

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An exogenous gene was expressed in the mammary epithelium of transgenic mice in the hope that the encoded protein could be secreted into milk. The transgenic mice carrying the promoter and upstream regulatory sequences from the sheep BLG gene which were fused to cDNA encoding human tissue plasminogen activator (tPA) with its endogenous secretion signal sequence were generated. The hybrid genes were microinjected into mouse embryos. Two mice were identified as being transgenic by Southern blot. Milk obtained from lactating females contained biologically active tPA, and its concentration was calculated to be about 1.5 microg/ml. This result establishes the feasibility of secreting protein into the milk of transgenic animals for production of biologically active tPA proteins, and may provide a powerful method to produce such proteins on a large scale. PMID:10503638

Zhou, J; Deng, J; Huang, P; Huang, C

1998-01-01

137

Urokinase Plasminogen Activator Receptor (uPAR) and Plasminogen Activator Inhibitor-1 (PAI-1) Are Potential Predictive Biomarkers in Early Stage Oral Squamous Cell Carcinomas (OSCC)  

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Oral squamous cell carcinoma (OSCC) is often associated with metastatic disease and a poor 5 year survival rate. Patients diagnosed with small tumours generally have a more favourable outcome, but some of these small tumours are aggressive and lead to early death. To avoid harmful overtreatment of patients with favourable prognosis, there is a need for predictive biomarkers that can be used for treatment stratification. In this study we assessed the possibility to use components of the plasminogen activator (PA) system as prognostic markers for OSCC outcome and compared this to the commonly used biomarker Ki-67. A tissue-micro-array (TMA) based immunohistochemical analysis of primary tumour tissue obtained from a North Norwegian cohort of 115 patients diagnosed with OSCC was conducted. The expression of the biomarkers was compared with clinicopathological variables and disease specific death. The statistical analyses revealed that low expression of uPAR (p?=?0.031) and PAI-1 (p?=?0.021) in the tumour cells was significantly associated with low disease specific death in patients with small tumours and no lymph node metastasis (T1N0). The commonly used biomarker, Ki-67, was not associated with disease specific death in any of the groups of patients analysed. The conclusion is that uPAR and PAI-1 are potential predictive biomarkers in early stage tumours and that this warrants further studies on a larger cohort of patients. PMID:24999729

Hadler-Olsen, Elin; Uhlin-Hansen, Lars; Svineng, Gunbj?rg

2014-01-01

138

Reduced Plasminogen Binding and Delayed Activation Render ?'-Fibrin More Resistant to Lysis than ?A-Fibrin.  

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Fibrin (Fn) clots formed from ?'-fibrinogen (?'-Fg), a variant with an elongated ?-chain, are resistant to lysis when compared with clots formed from the predominant ?A-Fg, a finding previously attributed to differences in clot structure due to delayed thrombin-mediated fibrinopeptide (FP) B release or impaired cross-linking by factor XIIIa. We investigated whether slower lysis of ?'-Fn reflects delayed plasminogen (Pg) binding and/or activation by tissue plasminogen activator (tPA), reduced plasmin-mediated proteolysis of ?'-Fn, and/or altered cross-linking. Clots formed from ?'-Fg lysed more slowly than those formed from ?A-Fg when lysis was initiated with tPA/Pg when FPA and FPB were both released, but not when lysis was initiated with plasmin, or when only FPA was released. Pg bound to ?'-Fn with an association rate constant 22% lower than that to ?A-Fn, and the lag time for initiation of Pg activation by tPA was longer with ?'-Fn than with ?A-Fn. Once initiated, however, Pg activation kinetics were similar. Factor XIIIa had similar effects on clots formed from both Fg isoforms. Therefore, slower lysis of ?'-Fn clots reflects delayed FPB release, which results in delayed binding and activation of Pg. When clots were formed from Fg mixtures containing more than 20% ?'-Fg, the upper limit of the normal level, the delay in lysis was magnified. These data suggest that circulating levels of ?'-Fg modulate the susceptibility of clots to lysis by slowing Pg activation by tPA and provide another example of the intimate connections between coagulation and fibrinolysis. PMID:25128532

Kim, Paul Y; Vu, Trang T; Leslie, Beverly A; Stafford, Alan R; Fredenburgh, James C; Weitz, Jeffrey I

2014-10-01

139

Crystal structure of plasminogen activator inhibitor-1 in an active conformation with normal thermodynamic stability  

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The serpin plasminogen activator inhibitor-1 (PAI-1) is a crucial regulator in fibrinolysis and tissue remodeling. PAI-1 has been associated with several pathological conditions and is a validated prognostic marker in human cancers. However, structural information about the native inhibitory form of PAI-1 has been elusive because of its inherent conformational instability and rapid conversion to a latent, inactive structure. Here we report the crystal structure of PAI-1 W175F at 2.3 ? resolution as the first model of the metastable native molecule. Structural comparison with a quadruple mutant (14-1B) previously used as representative of the active state uncovered key differences. The most striking differences occur near the region that houses three of the four mutations in the 14-1B PAI-1 structure. Prominent changes are localized within a loop connecting ?-strand 3A with the F helix, in which a previously observed 3(10)-helix is absent in the new structure. Notably these structural changes are found near the binding site for the cofactor vitronectin. Because vitronectin is the only known physiological regulator of PAI-1 that slows down the latency conversion, the structure of this region is important. Furthermore, the previously identified chloride-binding site close to the F-helix is absent from the present structure and likely to be artifactual, because of its dependence on the 14-1B mutations. Instead we found a different chlorine-binding site that is likely to be present in wild type PAI-1 and that more satisfactorily accounts for the chlorine stabilizing effect on PAI-1.

Jensen, Jan K; Thompson, Lawrence C

2011-01-01

140

Oxidized LDL and lysophosphatidylcholine stimulate plasminogen activator inhibitor-1 expression in vascular smooth muscle cells.  

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Plasminogen activator inhibitor-1 (PAI-1) functions as an important regulator of fibrinolysis by inhibiting both tissue-type and urokinase-type plasminogen activator. PAI-1 is produced by smooth muscle cells (SMCs) in atherosclerotic arteries, but the mechanisms responsible for induction of PAI-1 in SMCs are less well understood. In cultured human aortic SMCs, PAI-1 mRNA expression and protein secretion were increased after incubation with oxidized low-density lipoprotein (LDL) and the lipid peroxidation product lysophosphatidylcholine, whereas the effects of native LDL on PAI-1 production and release were more variable and did not reach statistical significance. The effect of LDL on arterial expression of PAI-1 in vivo was also studied in an animal model. Intravenous injection of human LDL in Sprague-Dawley rats resulted in accumulation of apolipoprotein B in the aorta within 12 hours as assessed by immunohistochemical testing. Epitopes specific for oxidized LDL began to develop in the aorta 12 hours after injection of LDL and peaked at 24 hours; this peak was accompanied by intense expression of PAI-1 immunoreactivity in the media. Also, increased aortic expression of PAI-1 mRNA after LDL injection was detected by using in situ hybridization. The transcription factor activator protein-1, which is known to bind to the promoter of the PAI-1 gene, was activated in the aortic wall 24 hours after LDL injection as assessed by electrophoretic mobility shift assay. Pretreatment of LDL with the antioxidant probucol decreased expression of oxidized LDL and PAI-1 immunoreactivity and activator protein-1 induction in the aorta but did not affect expression of apolipoprotein B immunoreactivity. These findings demonstrate that LDL oxidation enhances secretion of PAI-1 from cultured SMCs and that a similar mechanism may be involved in vascular expression of PAI-1. PMID:10591684

Dichtl, W; Stiko, A; Eriksson, P; Goncalves, I; Calara, F; Banfi, C; Ares, M P; Hamsten, A; Nilsson, J

1999-12-01

 
 
 
 
141

Acceleration of tissue plasminogen activator-mediated thrombolysis by magnetically powered nanomotors.  

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Dose control and effectiveness promotion of tissue plasminogen activator (t-PA) for thrombolysis are vitally important to alleviate serious side effects such as hemorrhage in stroke treatments. In order to increase the effectiveness and reduce the risk of stroke treatment, we use rotating magnetic nanomotors to enhance the mass transport of t-PA molecules at the blood clot interface for local ischemic stroke therapy. The in vitro experiments demonstrate that, when combined with magnetically activated nanomotors, the thrombolysis speed of low-concentration t-PA (50 ?g mL(-1)) can be enhanced up to 2-fold, to the maximum lysis speed at high t-PA concentration. Based on the convection enhanced transport theory due to rotating magnetic nanomotors, a theoretical model is proposed and predicts the experimental results reasonably well. The validity and efficiency of this enhanced treatment has been demonstrated in a rat embolic model. PMID:25006696

Cheng, Rui; Huang, Weijie; Huang, Lijie; Yang, Bo; Mao, Leidong; Jin, Kunlin; ZhuGe, Qichuan; Zhao, Yiping

2014-08-26

142

The activation of bovine plasminogen by PauA is not required for virulence of Streptococcus uberis.  

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A mutant of Streptococcus uberis carrying a single copy of ISS1 within pauA was unable to activate bovine plasminogen. Contrary to a hypothesis postulated previously, this mutation did not alter the ability of the bacterium to grow in milk or to infect the lactating bovine mammary gland. PMID:14638815

Ward, Philip N; Field, Terence R; Rapier, Christopher D; Leigh, James A

2003-12-01

143

Procollagen-III in serum, plasminogen activation and fibronectin in bronchoalveolar lavage fluid during and following irradiation of human lung  

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In the search for predictors of late radiation-induced lung injury we studied procollagen type III peptide concentration (P-III-P) in serum as well as fibronectin and plasminogen activation in bronchoalveolar lavage (BAL) fluid during and following irradiation of human lung. The patients received either high-dose hemithorax irradiation for pleural mesothelioma (11 patients) or high-dose irradiation with individually shaped fields for non-small cell lung cancer (12 patients). The severity of radiation fibrosis was assessed clinically from CT scans 6 months and 12 months after treatment. Four scores were used: severe, moderate, mild, or normal. Radiological lung injury varied from 'severe' (9 patients) to near absence of injury-'normal' (6 patients). Serum levels of P-III-P, when measured weekly during the 5-week period of radiotherapy or at several time-points after treatment, did not show consistent changes, nor did the levels correlate with the score for radiation fibrosis as assessed by CT scanning. Changes in fibronectin levels or in markers of plasminogen activation in BAL fluid did not correlate with the development of late lung injury. The levels of BAL fluid plasmin and plasminogen activator as assessed zymographically, but not the free net enzyme values, showed a tendency to be elevated in patients with severe radiation-induced lung injury, suggesting a possible role for inhibitors of the plasminogen activation cascade in the process of radiation-induced lung in the process of radiation-induced lung injury

144

Successful thrombolysis of a thrombosed prosthetic mitral valve using a synthetic tissue plasminogen activator: a case report  

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Abstract Introduction Prosthetic valve thrombosis is a rare but life-threatening condition that requires careful evaluation and prompt treatment. While surgical intervention remains the gold standard, thrombolytic therapy is now emerging as a potential substitute. Various thrombolytic treatments including streptokinase, urokinase and recombinant tissue plasminogen activators have been reported with variable success rates. However, the data on the use of tenecteplase (a synthe...

Al-Fadhli Jamal; Al-Shammari Fahad; Al-Sarraf Nael; Al-Shawaf Emad

2010-01-01

145

[Plasminogen activator inhibitor type 1 activity in women with unexplained very early recurrent pregnancy loss].  

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The aim of the study was to assess the independent role of polymorphism 4G/5G (PL 4G/5G)--genotype 4G/4G in plasminogen activator inhibitor type 1 (PAI-1) in the development of very early recurrent pregnancy loss (RPL)--before 10 weeks of gestation of pregnancy. The polymorphism 4G/5G as well as Factor V Leiden (FVL), prothrombin (FII) gene mutation 20210 G > A and polymorphism 677 C > T in methylentetrahydrofolat reductase (MTHFR) gene was investigated in 110 women with recurrent pregnancy loss before 10 weeks of gestation and in 97 healthy women with at least one uncomplicated full-term pregnancy. A significant prevalence of PL 4G/5G in women with RPL was found in comparison to prevalence of the polymorphism in controls (41.8% versus 26.8% respectively in patients and controls, OR: 1.96, 95% CI: 1.05 3.69, p = 0.034). The difference in prevalence of the polymorphism remains still significant after exclusion of patients and control carriers of FVL, FII 202010 G > A and 677 C > T in MTHFR (the prevalence of PL 4G/5G alone was 44.1% and 24% respectively in patients and controls, OR: 2,5, 95% CI: 1,15 5, 45, p = 0.018). The found association of PL 4G/5G in PAI-1 with early recurrent pregnancy loss encourage an extension of the list of inherited thrombophilic factors with this one. This result also could have had an implication for adjustment of further prophylactic low-molecular weight heparin implication in further pregnancy to prevent a poor foetal outcome. PMID:21268395

Ivanov, P; Komsa-Penkova, R; Ivanov, I; Konova, E; Kovacheva, K; Simeonova, M; Tanchev, S

2010-01-01

146

Mechanism of the stimulatory effect of native fucoidan, highly sulfated fucoidan and heparin on plasminogen activation by tissue plasminogen activator: the role of chloride.  

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Native Fucoidan and unfractionated heparin enhanced by 6-fold the in vitro activation of human glutamic plasminogen (Glu-Plg) by tissue plasminogen activator (t-PA) using 0.05M Tris buffer pH 7.4, while sulfated fucoidan inhibited the activation under these conditions. Double reciprocal plots of these interactions showed that sulfated fucoidan inhibited the activation in a noncompetitive manner while the enhancements by heparin or native fucoidan were due to an increase of Vmax without affecting Km. To determine whether the stimulatory effect of the individual cofactor was due to its interaction with Glu-Plg or with t-PA, experiments were performed at a fixed level of the cofactor and either varying in a serial fashion the concentration of Glu-Plg or of t-PA. The ratios of the initial rate of plasmin generation in the presence or absence of the cofactors were plotted against the inverse of the volume fraction of Glu-Plg or of t-PA. The results showed that heparin interacted with Glu-Plg while native fucoidan and sulfated fucoidan interacted with t-PA. Studies were also conducted on the effect of the two fucoidans and heparin on the activation of Glu-Plg by t-PA using 0.05M Tris buffer pH 7.4 containing 0.1 M NaCl. Under these conditions, sulfated fucoidan was most effective in enhancing the activation followed by native fucoidan and heparin respectively. The results of this study showed that in presence of the buffer containing 0.1 M NaCl, heparin was interacting with t-PA while the two fucoidans were interacting with both t-PA and Glu-Plg. A comparison of the double reciprocal plots of the rate of enhancement by the cofactors using 0.05M Tris buffer pH 7.4 containing 0.1M NaCl or in presence of buffer alone showed that the cofactors were more effective using 0.05M Tris buffer pH 7.4 alone and that addition of NaCl to the buffer slowed down the reactions by decreasing Vmax without affecting Km. Circular Dichroism (CD) studies of Glu-Plg in the far ultraviolet (UV) range showed that addition of NaCl destabilized the beta sheet structure which was reversed by addition of 6-aminohexanoic acid (6-AH) or one of the cofactors, while the near UV CD spectra of Glu-Plg in presence of 0.1 M NaCl was enhanced by the cofactors by increasing its ellipticity as reported earlier for 6-AH. PMID:15726889

Lang, DeShawn; Williams, Talya; Phillips, Altovise; Doctor, V M

2004-01-01

147

Urokinase-type plasminogen activator-like proteases in teleosts lack genuine receptor-binding epidermal growth factor-like domains  

DEFF Research Database (Denmark)

Plasminogen activation catalyzed by urokinase-type plasminogen activator (uPA) plays an important role in normal and pathological tissue remodeling processes. Since its discovery in the mid-1980s, the cell membrane-anchored urokinase-type plasminogen activator receptor (uPAR) has been believed to be central to the functions of uPA, as uPA-catalyzed plasminogen activation activity appeared to be confined to cell surfaces through the binding of uPA to uPAR. However, a functional uPAR has so far only been identified in mammals. We have now cloned, recombinantly produced, and characterized two zebrafish proteases, zfuPA-a and zfuPA-b, which by several criteria are the fish orthologs of mammalian uPA. Thus, both proteases catalyze the activation of fish plasminogen efficiently and both proteases are inhibited rapidly by plasminogen activator inhibitor-1 (PAI-1). But zfuPA-a differs from mammalian uPA by lacking the exon encoding the uPAR-binding epidermal growth factor-like domain; zfuPA-b differs from mammalian uPA by lacking two cysteines of the epidermal growth factor-like domain and a uPAR-binding sequence comparable with that found in mammalian uPA. Accordingly, no zfuPA-b binding activity could be found in fish white blood cells or fish cell lines. We therefore propose that the current consensus of uPA-catalyzed plasminogen activation taking place on cell surfaces, derived from observations with mammals, is too narrow. Fish uPAs appear incapable of receptor binding in the manner known from mammals and uPA-catalyzed plasminogen activation in fish may occur mainly in solution. Studies with nonmammalian vertebrate species are needed to obtain a comprehensive understanding of the mechanism of plasminogen activation.

Bager, René; Kristensen, Thomas K.

2012-01-01

148

Ex vivo bubble production from ovine large blood vessels: size on detachment and evidence of "active spots".  

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Nanobubbles formed on the hydrophobic silicon wafer were shown to be the source of gas micronuclei from which bubbles evolved during decompression. Bubbles were also formed after decompression on the luminal surface of ovine blood vessels. Four ovine blood vessels: aorta, pulmonary vein, pulmonary artery, and superior vena cava, were compressed to 1013 kPa for 21 h. They were then decompressed, photographed at 1-s intervals, and bubble size was measured on detachment. There were certain spots at which bubbles appeared, either singly or in a cluster. Mean detachment diameter was between 0.7 and 1.0 mm. The finding of active spots at which bubbles nucleate is a new, hitherto unreported observation. It is possible that these are the hydrophobic spots at which bubbles nucleate, stabilise, and later transform into the gas micronuclei that grow into bubbles. The possible neurological effects of these large arterial bubbles should be further explored. PMID:24933644

Arieli, R; Marmur, A

2014-08-15

149

Concentrations of plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in induced sputum of asthma patients after allergen challenge.  

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Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 are involved in tiisue remodeling and repair processes associated with acute and chronic inflammation. The aim of the study was to evaluate the effect of allergen challenge on concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. Thirty HDM-AAs and ten healthy persons (HCswere recruited for the study. In 24 HDM-AAs bronchial challenge with Dermatophagoides pteronyssinus (Dp and in 6 HDM-AAs sham challenege with saline were performed. In HDM-AAs sputum was induced 24 hours before (T0 and 24 hours (T24 after the challenge. Concentration of uPA and PAI-1 in induced sputum were determined using immunoenzymatic assays. At T0 in HDM-AAs mean sputum uPA (151 Â? 96 pg/ml and PAI-1 (4341 Â? 1262 pg/ml concentrations were higher than in HC (18.8 Â? 6.7 pg/ml; p=0.0002 and 596 Â? 180 pg/ml; p<0.0001; for uPA and PAI-1 respectively. After allergen challenge further increase in sputum uPA (187 Â? 144 pg/ml; p=0.03 and PAI-1 (6252 Â? 2323 pg/ml; p<0.0001 concentrations were observed. Moreover, in Dp challenged, but not in saline challenged HDM-AAs the mean uPA/PAI-1 ratio decreased significantly at T24. No significant increase in the studied parameters were found in sham challenged patients. In HDM-AAs allergen exposure leads to activation of the plasmin system in the airways. Greater increase of the PAI-1 concentration than uPA concentration after allergen challenge may promote airway remodeling and play an important role in the development of bronchial hyperreactivity.

Marcin Moniuszko

2011-04-01

150

Concentrations of plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in induced sputum of asthma patients after allergen challenge  

Directory of Open Access Journals (Sweden)

Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 are involved in tiisue remodeling and repairprocesses associated with acute and chronic inflammation. The aim of the study was to evaluate the effect of allergen challengeon concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. ThirtyHDM-AAs and ten healthy persons (HCswere recruited for the study. In 24 HDM-AAs bronchial challenge with Dermatophagoidespteronyssinus (Dp and in 6 HDM-AAs sham challenege with saline were performed. In HDM-AAs sputumwas induced 24 hours before (T0 and 24 hours (T24 after the challenge. Concentration of uPA and PAI-1 in induced sputumwere determined using immunoenzymatic assays. At T0 in HDM-AAs mean sputum uPA (151±96 pg/ml and PAI-1(4341±1262 pg/ml concentrations were higher than in HC (18.8±6.7 pg/ml; p=0.0002 and 596±180 pg/ml; p<0.0001; foruPA and PAI-1 respectively. After allergen challenge further increase in sputum uPA (187±144 pg/ml; p=0.03 and PAI-1(6252±2323 pg/ml; p<0.0001 concentrations were observed. Moreover, in Dp challenged, but not in saline challengedHDM-AAs the mean uPA/PAI-1 ratio decreased significantly at T24. No significant increase in the studied parameters werefound in sham challenged patients. In HDM-AAs allergen exposure leads to activation of the plasmin system in the airways.Greater increase of the PAI-1 concentration than uPA concentration after allergen challenge may promote airway remodelingand play an important role in the development of bronchial hyperreactivity.

Krzysztof Kowal,

2010-04-01

151

Large scale, rapid purification of recombinant tissue-type plasminogen activator.  

Science.gov (United States)

Recombinant tissue-type plasminogen activator (rt-PA) from cultures of a genetically manipulated Bowes melanoma cell line (TRBM6) was purified in batches of average volume 451 using an autoclavable, reusable, continuous chromatography system comprising zinc chelate-Sepharose CL4B and lysine-Sepharose CL4B. After eight successive purifications the rt-PA was ultrafiltered to yield a preparation containing 4.9 mg protein/ml and 2.7 X 10(6) IU/ml. Analysis by SDS-polyacrylamide gel electrophoresis followed by staining with Coomassie brilliant blue R250 showed major protein bands at Mr = 63,000 and 65,000; most of the material was in the 1-chain form. The potential usefulness of a simple, rapid continuous chromatography system that can be operated under aseptic conditions is discussed. PMID:3100325

Dodd, I; Jalalpour, S; Southwick, W; Newsome, P; Browne, M J; Robinson, J H

1986-12-01

152

[Characterization of the primary structure of TNK-tissue plasminogen activator using LC-MS].  

Science.gov (United States)

The primary structure of TNK-tissue plasminogen activator (TNK-tPA) was characterized using liquid chromatography-mass spectrometry (LC-MS). Firstly, the molecular mass of deglycosylated protein was measured. Then peptide mass mapping and MS/MS of the reduced, alkylated and trypsin-digested sample were tested and analyzed so as to verify its amino acid sequence and identify post-translational modifications. Results show that the amino acid sequence was consistent with designed structure; about 5% of M207 was oxidized; T61 was fucosylated with -80% occupancy; N103, N448 and N184 (-15% occupancy) were glycosylated with complex-type oligosaccharides. LC-MS coupled with proper sample pretreatment is approved to be a rapid and powerful approach to characterize the primary structure of TNK-tPA. PMID:23984525

Tao, Lei; Ding, You-Xue; Guo, Ying; Rao, Chun-Ming; Wang, Jun-Zhi

2013-06-01

153

Stereotactic fibrinolysis of spontaneous intracerebral hematoma using infusion of recombinant tissue plasminogen activator  

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Full Text Available PURPOSE: The authors present a prospective study on 10 patients with stereotactic infusion of tissue plasminogen activator (rtPA intraparenchimal hemorrhage. METHODS: Between 1999 and 2000, 10 patients with deep seated hematomas in the basal ganglia were selected for stereotactic infusion of rtPA and spontaneous clot drainage. RESULTS: All cases had about 80% reduction of the hematoma volume in the CT scan at the third day. The intracranial pressure was normalized by the third day too. There were no local or systemic complications with the use of this trombolitic. The results were shown by the Glasgow Outcome Scale with six patients in V, three in IV and one in III after 3 months. CONCLUSION: Early treatment and drainage with minimally invasive neurosurgery , can make these patients with deep-seated hematomas recover the consciousness and they can be rehabilitated earlier avoiding secondary complications.

Nasser José Augusto

2002-01-01

154

Ischaemia-reperfusion injury impairs tissue plasminogen activator release in man  

DEFF Research Database (Denmark)

AimsIschaemia-reperfusion (IR) injury causes endothelium-dependent vasomotor dysfunction that can be prevented by ischaemic preconditioning. The effects of IR injury and preconditioning on endothelium-dependent tissue plasminogen activator (t-PA) release, an important mediator of endogenous fibrinolysis, remain unknown.Methods and resultsIschaemia-reperfusion injury (limb occlusion at 200 mmHg for 20 min) was induced in 22 healthy subjects. In 12 subjects, IR injury was preceded by local or remote ischaemic preconditioning (three 5 min episodes of ipsilateral or contralateral limb occlusion, respectively) or sham in a randomized, cross-over trial. Forearm blood flow (FBF) and endothelial t-PA release were assessed using venous occlusion plethysmography and venous blood sampling during intra-arterial infusion of acetylcholine (5-20 µg/min) or substance P (2-8 pmol/min). Acetylcholine and substance P caused dose-dependent increases in FBF (P

Pedersen, Christian MØller; Barnes, Gareth

2011-01-01

155

Intra-arterial tissue plasminogen activator and abciximab in patients with acute basilar artery occlusion.  

Science.gov (United States)

Acute basilar artery occlusion has a poor prognosis and best treatment has not been assessed yet; as for intra-arterial treatment, no "gold standard" exists. We evaluated a series of ten patients treated with intra-arterial combination of recombinant tissue plasminogen activator (rtPA) and abciximab. Partial/complete recanalisation was achieved in all patients and good outcome (1 month Modified Rankin Scale 0-2) in eight cases, while one patient had symptomatic intracranial haemorrhage and died. Such outcome appears significantly better if compared with the results of Basilar Artery International Cooperation Study, suggesting that intra-arterial administration of rtPA and abciximab may be a promising option in patients with acute basilar artery occlusion undergoing endovascular treatment. PMID:23703399

Chiti, A; Gialdini, G; Terni, E; Giannini, N; Gennaro, M; Lazzarotti, G A; Puglioli, M; Orlandi, G; Bonuccelli, U

2013-10-01

156

RNA aptamers as conformational probes and regulatory agents for plasminogen activator inhibitor-1  

DEFF Research Database (Denmark)

The hallmark of serpins is the ability to undergo the so-called "stressed-to-relaxed" switch during which the surface-exposed reactive center loop (RCL) becomes incorporated as strand 4 in central beta-sheet A. RCL insertion drives not only the inhibitory reaction of serpins with their target serine proteases but also the conversion to the inactive latent state. RCL insertion is coupled to conformational changes in the flexible joint region flanking beta-sheet A. One interesting serpin is plasminogen activator inhibitor-1 (PAI-1), a fast and specific inhibitor of the serine proteases tissue-type and urokinase-type plasminogen activator. Via its flexible joints' region, native PAI-1 binds vitronectin and relaxed, protease-complexed PAI-1 certain endocytosis receptors. From a library of 35-nucleotides long 2'-fluoropyrimidine-containing RNA oligonucleotides, we have isolated two aptamers binding PAI-1 by the flexible joint region with low nanomolar K(D) values. One of the aptamers exhibited measurable binding to native PAI-1 only, while the other also bound relaxed PAI-1. While none of the aptamers inhibited the antiproteolytic effect of PAI-1, both aptamers inhibited vitronectin binding and the relaxed PAI-1-binding aptamer also endocytosis receptor binding. The aptamer binding exclusively to native PAI-1 increased the half-life for the latency transition to more than 6 h, manyfold more than vitronectin. Contact with Lys124 in the flexible joint region was critical for strong inhibition of the latency transition and the lack of binding to relaxed PAI-1. We conclude that aptamers yield important information about the serpin conformational switch and, because they can compete with high-affinity protein-protein interactions, may provide leads for pharmacological intervention.

Madsen, Jeppe B; Dupont, Daniel Miotto

2010-01-01

157

Correlation between plasminogen activator inhibitor-1 (PAI-1) and infarct size in acute myocardial infarction  

International Nuclear Information System (INIS)

The purpose of this study was to clarify the effects of fibrinolytic changes on infarct size in patients with acute myocardial infarction (AMI). Thirty-one patients with first AMI were divided into 2 groups: 15 patients (group C) underwent neither direct percutaneous transluminal coronary angioplasty (PTCA) nor thrombolytic therapy and 16 patients (group P) underwent successful direct PTCA. We measured serial changes in plasma level of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). Furthermore, the relationship of these factors with the size of perfusion defects in Thallium-201 myocardial imaging (extent score) and peak creatine kinase (CK) were studied. Results obtained were as follows: In group C, plasma PAI-1 levels showed a tendency to increase within 24 hours after the onset of AMI compared with the control values and remained high on the 28th day. In group P, these levels increased within 24 hours and gradually decreased from the 7th day to the 28th day, but remained high on the 28th day compared with the control values. In group C, plasma t-PA levels increased within 24 hours, decreased on the 7th day, and increased again on the 28th day. In group P, these levels increased within 24 hours and gradually decreased from the 7th day to the 28th day. In both groups, PAI-1 levels within 24 hours correlated positively with the extent score. In group C, PAI-1 levels on the 1st day correlated positively with the levels of peak CK on tpositively with the levels of peak CK on the 1st day. On the other hand, this correlations was not shown in the group P. From these results, it is suggested that the plasma PAI-1 has the characteristics of an acute phase reactant and the PAI-1 level within 24 hours after the onset of AMI reflects the infarct size. (author)

158

Correlation between plasminogen activator inhibitor-1 (PAI-1) and infarct size in acute myocardial infarction  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to clarify the effects of fibrinolytic changes on infarct size in patients with acute myocardial infarction (AMI). Thirty-one patients with first AMI were divided into 2 groups: 15 patients (group C) underwent neither direct percutaneous transluminal coronary angioplasty (PTCA) nor thrombolytic therapy and 16 patients (group P) underwent successful direct PTCA. We measured serial changes in plasma level of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). Furthermore, the relationship of these factors with the size of perfusion defects in Thallium-201 myocardial imaging (extent score) and peak creatine kinase (CK) were studied. Results obtained were as follows: In group C, plasma PAI-1 levels showed a tendency to increase within 24 hours after the onset of AMI compared with the control values and remained high on the 28th day. In group P, these levels increased within 24 hours and gradually decreased from the 7th day to the 28th day, but remained high on the 28th day compared with the control values. In group C, plasma t-PA levels increased within 24 hours, decreased on the 7th day, and increased again on the 28th day. In group P, these levels increased within 24 hours and gradually decreased from the 7th day to the 28th day. In both groups, PAI-1 levels within 24 hours correlated positively with the extent score. In group C, PAI-1 levels on the 1st day correlated positively with the levels of peak CK on the 1st day. On the other hand, this correlations was not shown in the group P. From these results, it is suggested that the plasma PAI-1 has the characteristics of an acute phase reactant and the PAI-1 level within 24 hours after the onset of AMI reflects the infarct size. (author)

Soeki, Takeshi; Tamura, Yoshiyuki; Takeichi, Naoki; Shinohara, Hisanori; Yui, Yasuko; Fukuda, Nobuo; Sui, Osamu [Zentsuji National Hospital, Kagawa (Japan)

1998-05-01

159

Relationship between plasminogen activator inhibitor-1 antigen, leptin, and fat mass in obese children and adolescents.  

Science.gov (United States)

Hyperleptinemia may be associated with cardiovascular risk and is linked with parameters of fibrinolytic processes in adults. We studied whether body fatness, leptin, and insulin interact with plasminogen activator inhibitor-1 antigen (PAI-1-Ag) and tissue-type plasminogen activator antigen (tPA-Ag) in obese children and adolescents. Twenty-three boys (mean +/- SD: age, 10.7 +/- 3.3 years; body mass index [BMI], 28.7 +/- 5.4 Kg/m2) and 19 girls (age, 11.9 +/- 2.7 years; BMI, 29.4 +/- 4.8 Kg/m2) were investigated. Body fat mass (FM) in the children was calculated by bioelectrical impedance analysis, and blood samples were obtained for leptin, insulin, C-peptide, PAI-1-Ag, and tPA-Ag. The children were divided into 3 subgroups according to maturation. Maturity was associated with greater adiposity and higher levels of leptin and C-peptide, but insulin and PAI-1-Ag were not different between prepubertal, pubertal, and late/postpubertal children. PAI-1-Ag was associated with leptin and insulin, but not after adjustment for fatness. PAI-1-Ag was independently associated with tPA-Ag (r = .36, P age, or leptin contributed significantly to the variation in either PAI-1-Ag or tPA-Ag. Our data suggest that adiposity and other variables contribute to higher levels of PAI-1-Ag. Leptin seems not to be independently linked with fibrinolytic parameters, but an unfavorable metabolic and fibrinolytic risk profile might emanate from the obese pubertal stage. PMID:10910001

Sudi, K M; Gallistl, S; Weinhandl, G; Muntean, W; Borkenstein, M H

2000-07-01

160

Plasminogen Acquisition and Activation at the Surface of Leptospira Species Lead to Fibronectin Degradation ?  

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Pathogenic Leptospira species are the etiological agents of leptospirosis, a widespread disease of human and veterinary concern. In this study, we report that Leptospira species are capable of binding plasminogen (PLG) in vitro. The binding to the leptospiral surface was demonstrated by indirect immunofluorescence confocal microscopy with living bacteria. The PLG binding to the bacteria seems to occur via lysine residues because the ligation is inhibited by addition of the lysine analog 6-aminocaproic acid. Exogenously provided urokinase-type PLG activator (uPA) converts surface-bound PLG into enzymatically active plasmin, as evaluated by the reaction with the chromogenic plasmin substrate d-Val-Leu-Lys 4-nitroanilide dihydrochloridein. The PLG activation system on the surface of Leptospira is PLG dose dependent and does not cause injury to the organism, as cellular growth in culture was not impaired. The generation of active plasmin within Leptospira was observed with several nonvirulent high-passage strains and with the nonpathogenic saprophytic organism Leptospira biflexa. Statistically significant higher activation of plasmin was detected with a low-passage infectious strain of Leptospira. Plasmin-coated virulent Leptospira interrogans bacteria were capable of degrading purified extracellular matrix fibronectin. The breakdown of fibronectin was not observed with untreated bacteria. Our data provide for the first time in vitro evidence for the generation of active plasmin on the surface of Leptospira, a step that may contribute to leptospiral invasiveness. PMID:19581392

Vieira, Monica L.; Vasconcellos, Silvio A.; Goncales, Amane P.; de Morais, Zenaide M.; Nascimento, Ana L. T. O.

2009-01-01

 
 
 
 
161

Intrapleural adenoviral delivery of human plasminogen activator inhibitor-1 exacerbates tetracycline-induced pleural injury in rabbits.  

Science.gov (United States)

Elevated concentrations of plasminogen activator inhibitor-1 (PAI-1) are associated with pleural injury, but its effects on pleural organization remain unclear. A method of adenovirus-mediated delivery of genes of interest (expressed under a cytomegalovirus promoter) to rabbit pleura was developed and used with lacZ and human (h) PAI-1. Histology, ?-galactosidase staining, Western blotting, enzymatic and immunohistochemical analyses of pleural fluids (PFs), lavages, and pleural mesothelial cells were used to evaluate the efficiency and effects of transduction. Transduction was selective and limited to the pleural mesothelial monolayer. The intrapleural expression of both genes was transient, with their peak expression at 4 to 5 days. On Day 5, hPAI-1 (40-80 and 200-400 nM of active and total hPAI-1 in lavages, respectively) caused no overt pleural injury, effusions, or fibrosis. The adenovirus-mediated delivery of hPAI-1 with subsequent tetracycline-induced pleural injury resulted in a significant exacerbation of the pleural fibrosis observed on Day 5 (P = 0.029 and P = 0.021 versus vehicle and adenoviral control samples, respectively). Intrapleural fibrinolytic therapy (IPFT) with plasminogen activators was effective in both animals overexpressing hPAI-1 and control animals with tetracycline injury alone. An increase in intrapleural active PAI-1 (from 10-15 nM in control animals to 20-40 nM in hPAI-1-overexpressing animals) resulted in the increased formation of PAI-1/plasminogen activator complexes in vivo. The decrease in intrapleural plasminogen-activating activity observed at 10 to 40 minutes after IPFT correlates linearly with the initial concentration of active PAI-1. Therefore, active PAI-1 in PFs affects the outcome of IPFT, and may be both a biomarker of pleural injury and a molecular target for its treatment. PMID:23002099

Karandashova, Sophia; Florova, Galina; Azghani, Ali O; Komissarov, Andrey A; Koenig, Kathy; Tucker, Torry A; Allen, Timothy C; Stewart, Kris; Tvinnereim, Amy; Idell, Steven

2013-01-01

162

Circadian variation of tissue plasminogen activator and its inhibitor, von Willebrand factor antigen, and prostacyclin stimulating factor in men with ischaemic heart disease.  

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OBJECTIVES--To determine whether plasma concentrations of tissue plasminogen activator antigen, von Willebrand factor antigen, and prostacyclin stimulating factor and plasminogen activator inhibitor activity show circadian variation in men with ischaemic heart disease. DESIGN--Blood samples were obtained every four hours for 24 hours from 10 men with ischaemic heart disease. The men were ambulant from 08:10 until 00:00 when they went to bed and they remained in bed until 08:00 the following m...

Bridges, A. B.; Mclaren, M.; Scott, N. A.; Pringle, T. H.; Mcneill, G. P.; Belch, J. J.

1993-01-01

163

Testicular peritubular cells in culture secrete specific inhibitor(s) of plasminogen activators  

International Nuclear Information System (INIS)

Rat peritubular myoid cells in culture secrete component(s) which inhibit the activity of plasminogen activators (PA) produced by Sextoli cells, but do not inhibit the activity of plasmin. The PA inhibitor(s) (PA-I) block both urokinase-type PA (u-PA) secreted by sertoli cells under basal conditions, and tissue-type PA (t-PA) synthesized by Sertoli cells stimulated by follicle stimulating hormone or by cAMP derivatives. The approximate molecular mass of the PA-I is 55 kDa, as determined by gel exclusion chromatography; by polyacrylamide gel electrophoresis; and by reverse autography. Formation of high molecular mass complexes between PA-I and 125I-uPA is prevented by PMSF, indicating that the inhibitor-protease interaction occurs via the active center of the serine protease. Most of the peritubular cell PA-I activity can be immunoprecipitated by antibodies directed against a vascular endothelial cell PA-I. The authors conclude that peritubular myoid cells secrete one or more specific inhibitors of t-PA and u-PA. Possible functions of the PA-I in the modulation of seminiferous tubule restructuring during spermatogenesis will be discussed in relation to their previous observations that testicular PA production and secretion are greatest at discrete stages of the cycle

164

Modulation of staphylokinase-dependent plasminogen activation by mono- and divalent ions  

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Full Text Available The effect of several ions (Cl-, Na+, K+, Ca2+ on the rate of plasminogen (Pg activation by recombinant staphylokinase (rSTA is reported. Both monovalent and divalent ions affect the rate at which Pg is activated by rSTA, in a concentration-dependent manner (range 0-100 mM. In almost all cases, a decrease of the initial velocity of activation was observed. Cl- showed the most striking inhibitory effect at low concentrations (64% at 10 mM. However, in the presence of a fibrin surface, this inhibition was attenuated to 38%. Surprisingly, 10 mM Ca2+ enhanced the Pg activation rate 21% when a polymerized fibrin matrix was present. These data support the idea that ions can modulate the rate of Pg activation through a mechanism that may be associated with changes in the molecular conformation of the zymogen. This effect is strongly dependent on the presence of a fibrin clot.

A. Yarzábal

1999-01-01

165

Modulation of staphylokinase-dependent plasminogen activation by mono- and divalent ions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The effect of several ions (Cl-, Na+, K+, Ca2+) on the rate of plasminogen (Pg) activation by recombinant staphylokinase (rSTA) is reported. Both monovalent and divalent ions affect the rate at which Pg is activated by rSTA, in a concentration-dependent manner (range 0-100 mM). In almost all cases, [...] a decrease of the initial velocity of activation was observed. Cl- showed the most striking inhibitory effect at low concentrations (64% at 10 mM). However, in the presence of a fibrin surface, this inhibition was attenuated to 38%. Surprisingly, 10 mM Ca2+ enhanced the Pg activation rate 21% when a polymerized fibrin matrix was present. These data support the idea that ions can modulate the rate of Pg activation through a mechanism that may be associated with changes in the molecular conformation of the zymogen. This effect is strongly dependent on the presence of a fibrin clot.

A., Yarzábal; R.L., Serrano; J., Puig.

166

Coordinate regulation of fibronectin matrix assembly by the plasminogen activator system and vitronectin in human osteosarcoma cells  

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Full Text Available Abstract Background Plasminogen activators are known to play a key role in the remodeling of bone matrix which occurs during tumor progression, bone metastasis and bone growth. Dysfunctional remodeling of bone matrix gives rise to the osteoblastic and osteolytic lesions seen in association with metastatic cancers. The molecular mechanisms responsible for the development of these lesions are not well understood. Studies were undertaken to address the role of the plasminogen activator system in the regulation of fibronectin matrix assembly in the osteoblast-like cell line, MG-63. Results Treatment of MG-63 cells with P25, a peptide ligand for uPAR, resulted in an increase in assembly of fibronectin matrix which was associated with an increase in the number of activated ?1 integrins on the cell surface. Overexpression of uPAR in MG-63 cells increased the effect of P25 on fibronectin matrix assembly and ?1 integrin activation. P25 had no effect on uPAR null fibroblasts, confirming a role for uPAR in this process. The addition of plasminogen activator inhibitor Type I (PAI-1 to cells increased the P25-induced fibronectin polymerization, as well as the number of activated integrins. This positive regulation of PAI-1 on fibronectin assembly was independent of PAI-1's anti-proteinase activity, but acted through PAI-1 binding to the somatomedin B domain of vitronectin. Conclusion These results indicate that vitronectin modulates fibronectin matrix assembly in osteosarcoma cells through a novel mechanism involving cross-talk through the plasminogen activator system.

McKeown-Longo Paula J

2006-03-01

167

Circadian variation of tissue plasminogen activator and its inhibitor, von Willebrand factor antigen, and prostacyclin stimulating factor in men with ischaemic heart disease.  

Science.gov (United States)

OBJECTIVES--To determine whether plasma concentrations of tissue plasminogen activator antigen, von Willebrand factor antigen, and prostacyclin stimulating factor and plasminogen activator inhibitor activity show circadian variation in men with ischaemic heart disease. DESIGN--Blood samples were obtained every four hours for 24 hours from 10 men with ischaemic heart disease. The men were ambulant from 08:10 until 00:00 when they went to bed and they remained in bed until 08:00 the following morning. PATIENTS--Ten men with positive diagnostic exercise tolerance tests with no significant past history, who were not regularly taking any medical treatment except for glyceryl trinitrate. RESULTS--There was significant circadian variation in plasminogen activator inhibitor activity (p = 0.001) (peak value 04:00 and trough value 20:00), but not in plasma concentrations of tissue plasminogen activator antigen, von Willebrand factor, or prostacyclin stimulating factor. CONCLUSION--Men with ischaemic heart disease showed a significant circadian variation in fibrinolysis. The combination of peak values of plasminogen activator inhibitor activity and failure of plasma concentrations of tissue plasminogen activator antigen to increase in the early morning must predispose to thrombosis at this time. The circadian variation in fibrinolysis may contribute to the increased incidence of myocardial infarction in the morning. PMID:8435236

Bridges, A B; McLaren, M; Scott, N A; Pringle, T H; McNeill, G P; Belch, J J

1993-01-01

168

Binding and activation of host plasminogen on the surface of Francisella tularensis  

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Full Text Available Abstract Background Francisella tularensis (FT is a gram-negative facultative intracellular coccobacillus and is the causal agent of a life-threatening zoonotic disease known as tularemia. Although FT preferentially infects phagocytic cells of the host, recent evidence suggests that a significant number of bacteria can be found extracellularly in the plasma fraction of the blood during active infection. This observation suggests that the interaction between FT and host plasma components may play an important role in survival and dissemination of the bacterium during the course of infection. Plasminogen (PLG is a protein zymogen that is found in abundance in the blood of mammalian hosts. A number of both gram-positive and gram-negative bacterial pathogens have the ability to bind to PLG, giving them a survival advantage by increasing their ability to penetrate extracellular matrices and cross tissue barriers. Results We show that PLG binds to the surface of FT and that surface-bound PLG can be activated to plasmin in the presence of tissue PLG activator in vitro. In addition, using Far-Western blotting assays coupled with proteomic analyses of FT outer membrane preparations, we have identified several putative PLG-binding proteins of FT. Conclusions The ability of FT to acquire surface bound PLG that can be activated on its surface may be an important virulence mechanism that results in an increase in initial infectivity, survival, and/or dissemination of this bacterium in vivo.

Whitt Michael A

2010-03-01

169

Targeted delivery of tissue plasminogen activator by binding to silica-coated magnetic nanoparticle  

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Full Text Available Jyh-Ping Chen,1 Pei-Ching Yang,1 Yunn-Hwa Ma,2 Su-Ju Tu,3 Yu-Jen Lu1,41Department of Chemical and Materials Engineering, 2Department of Physiology and Pharmacology, 3Department of Medical Imaging and Radiological Sciences, Chang Gung University, Kwei-San, Taoyuan, Taiwan, Republic of China; 4Department of Neurosurgery, Chang Gung Memorial Hospital, Kwei-San, Taoyuan, Taiwan, Republic of ChinaBackground and methods: Silica-coated magnetic nanoparticle (SiO2-MNP prepared by the sol-gel method was studied as a nanocarrier for targeted delivery of tissue plasminogen activator (tPA. The nanocarrier consists of a superparamagnetic iron oxide core and an SiO2 shell and is characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, superconducting quantum interference device, and thermogravimetric analysis. An amine-terminated surface silanizing agent (3-aminopropyltrimethoxysilane was used to functionalize the SiO2 surface, which provides abundant —NH2 functional groups for conjugating with tPA.Results: The optimum drug loading is reached when 0.5 mg/mL tPA is conjugated with 5 mg SiO2-MNP where 94% tPA is attached to the carrier with 86% retention of amidolytic activity and full retention of fibrinolytic activity. In vitro biocompatibility determined by lactate dehydrogenase release and cell proliferation indicated that SiO2-MNP does not elicit cytotoxicity. Hematological analysis of blood samples withdrawn from mice after venous administration indicates that tPA-conjugated SiO2-MNP (SiO2-MNP-tPA did not alter blood component concentrations. After conjugating to SiO2-MNP, tPA showed enhanced storage stability in buffer and operation stability in whole blood up to 9.5 and 2.8-fold, respectively. Effective thrombolysis with SiO2-MNP-tPA under magnetic guidance is demonstrated in an ex vivo thrombolysis model where 34% and 40% reductions in blood clot lysis time were observed compared with runs without magnetic targeting and with free tPA, respectively, using the same drug dosage. Enhanced penetration of SiO2-MNP-tPA into blood clots under magnetic guidance was confirmed from microcomputed tomography analysis.Conclusion: Biocompatible SiO2-MNP developed in this study will be useful as a magnetic targeting drug carrier to improve clinical thrombolytic therapy.Keywords: magnetic nanoparticles, drug delivery, thrombolysis, tissue plasminogen activator, silica

Chen JP

2012-09-01

170

Tumor marker utility and prognostic relevance of cathepsin B, cathepsin L, urokinase-type plasminogen activator, plasminogen activator inhibitor type-1, CEA and CA 19-9 in colorectal cancer  

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Abstract Background Cathepsin B and L (CATB, CATL), urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 play an important role in colorectal cancer invasion. The tumor marker utility and prognostic relevance of these proteases have not been evaluated in the same experimental setting and compared with that of CEA and CA-19-9. Methods Protease, CEA and CA 19-9 serum or plasma levels were determined in 56 patients with colorectal cancer, 25 patients ...

De Paoli Massimo; Hritz István; Molnár László D; István Gábor; Cardin Romilda; Farinati Fabio; Herszényi László; Plebani Mario; Tulassay Zsolt

2008-01-01

171

Simvastatin suppresses dexamethasone-induced secretion of plasminogen activator inhibitor-1 in human bone marrow adipocytes  

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Full Text Available Abstract Background Osteonecrosis of the femoral head is a common complication of high-dose glucocorticoid treatment. Intravascular thrombosis is thought to be associated with the ischemic state of the femoral head. Plasminogen activator inhibitor-1 (PAI-1 is an adipokine, which are physiologically active substances secreted from visceral and subcutaneous adipocytes. PAI-1 suppresses fibrinolysis by binding tissue-type plasminogen activator. Several reports have described the relationship between PAI-1 and steroid-induced osteonecrosis of the femoral head, and the preventive effects of lipid-lowering agents (statins against steroid-induced osteonecrosis of the femoral head. We previously reported that adipokines and dexamethasone induced PAI-1 secretion from bone marrow adipocytes. The purpose of the present study is to examine the effects of simvastatin on PAI-1 secretion from human bone marrow adipocytes in vitro. Methods Primary bone marrow adipocytes were extracted from collagenase-treated bone marrow fluid obtained from the femoral necks of 40 patients (6 men, 34 women; age range, 52-81 years undergoing hip joint replacement surgery. After suspended culture with or without dexamethasone or simvastatin, PAI-1 mRNA expression was assessed by real-time RT-PCR. Total PAI-1 protein secretion in culture medium was assessed by enzyme-linked immunosorbent assay. Results PAI-1 mRNA expression was up-regulated by 388% (P = 0.002 with dexamethasone, and down-regulated by 45% (P = 0.002 with simvastatin, as compared to control levels. Dexamethasone increased total PAI-1 secretion by 166% (P = 0.001 and simvastatin decreased total PAI-1 secretion by 64% (P = 0.002. No significant changes were observed in adiponectin mRNA expression and secretion by dexamethasone and simvastatin, while pre-treatment with simvastatin reversed dexamethasone induced PAI-1 secretion by 89%, as compared to control levels. Conclusion The present study confirmed the suppressive effects of simvastatin on PAI-1 expression and secretion from bone marrow adipocytes. Furthermore, pre-treatment with simvastatin reversed dexamethasone induced PAI-1 secretion. Simvastatin may thus exhibit preventive effects against steroid-induced osteonecrosis of the femoral head by suppressing PAI-1 secretion.

Baba Hideo

2011-04-01

172

Bioconjugation of recombinant tissue plasminogen activator to magnetic nanocarriers for targeted thrombolysis  

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Full Text Available Hung-Wei Yang,1,* Mu-Yi Hua,1,* Kun-Ju Lin,2,* Shiaw-Pyng Wey,3 Rung-Ywan Tsai,4 Siao-Yun Wu,5 Yi-Ching Lu,5 Hao-Li Liu,6 Tony Wu,7 Yunn-Hwa Ma5 1Chang Gung Molecular Medicine Research Center, Department of Chemical and Materials Engineering, 2Molecular Imaging Center, Department of Nuclear Medicine, Chang Gung Memorial Hospital, Kuei-Shan, Tao-Yuan, Taiwan, Republic of China; 3Department of Medical Imaging and Radiological Sciences, 4Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsin-chu, Taiwan, Republic of China; 5Department of Physiology and Pharmacology and Healthy Aging Research Center, 6Department of Electrical Engineering, Chang Gung University, Kuei-Shan, Tao-Yuan, Taiwan, Republic of China; 7Department of Neurology, Chang Gung University College of Medicine and Memorial Hospital, Tao-Yuan, Taiwan, Republic of China*These authors contributed equally to this workAbstract: Low-toxicity magnetic nanocarriers (MNCs composed of a shell of poly [aniline-co-N-(1-one-butyric acid aniline] over a Fe3O4 magnetic nanoparticle core were developed to carry recombinant tissue plasminogen activator (rtPA in MNC-rtPA for targeted thrombolysis. With an average diameter of 14.8 nm, the MNCs exerted superparamagnetic properties. Up to 276 µg of active rtPA was immobilized per mg of MNCs, and the stability of the immobilized rtPA was greatly improved during storage at 4°C and 25°C. In vitro thrombolysis testing with a tubing system demonstrated that magnet-guided MNC-rtPA showed significantly improved thrombolysis compared with free rtPA and reduced the clot lysis time from 39.2 ± 3.2 minutes to 10.8 ± 4.2 minutes. In addition, magnet-guided MNC-rtPA at 20% of the regular rtPA dose restored blood flow within 15–25 minutes of treatment in a rat embolism model without triggering hematological toxicity. In conclusion, this improved system is based on magnetic targeting accelerated thrombolysis and is potentially amenable to therapeutic applications in thromboembolic diseases.Keywords: thrombolysis, recombinant tissue plasminogen activator, magnetic nanocarriers, magnetic targeting, targeting therapy

Yang HW

2012-10-01

173

Tissue Plasminogen Activator Alters Intracellular Sequestration of Zinc through Interaction with the Transporter ZIP4  

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Glutamatergic neurons contain free zinc packaged into neurotransmitter-loaded synaptic vesicles. Upon neuronal activation, the vesicular contents are released into the synaptic space, whereby the zinc modulates activity of postsynaptic neurons though interactions with receptors, transporters and exchangers. However, high extracellular concentrations of zinc trigger seizures and are neurotoxic if substantial amounts of zinc reenter the cells via ion channels and accumulate in the cytoplasm. Tissue plasminogen activator (tPA), a secreted serine protease, is also proepileptic and excitotoxic. However, tPA counters zinc toxicity by promoting zinc import back into the neurons in a sequestered form that is nontoxic. Here, we identify the zinc influx transporter, ZIP4, as the pathway through which tPA mediates the zinc uptake. We show that ZIP4 is upregulated after excitotoxin stimulation of the mouse, male and female, hippocampus. ZIP4 physically interacts with tPA, correlating with an increased intracellular zinc influx and lysosomal sequestration. Changes in prosurvival signals support the idea that this sequestration results in neuroprotection. These experiments identify a mechanism via which neurons use tPA to efficiently neutralize the toxic effects of excessive concentrations of free zinc.

Emmetsberger, Jaime; Mirrione, Martine M.; Zhou, Chun; Fernandez-Monreal, Monica; Siddiq, Mustafa M.; Ji, Kyungmin; Tsirka, Stella E. (SBU)

2010-09-17

174

Sustained thrombolysis with DNA-recombinant tissue type plasminogen activator in rabbits  

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Tissue type plasminogen activator (t-PA) is an effective thrombolytic agent in experimental animals. The duration of the thrombolytic effect of infused t-PA is unknown. The authors compared the duration of the thrombolytic effect of t-PA with streptokinase by measuring the lysis of 125I-fibrin-labeled thrombi in rabbit jugular veins at different times after a bolus injection of the fibrinolytic agents. The pharmacodynamics of both thrombolytic agents were determined in rabbits using a sensitive ex vivo fibrinolytic assay. Streptokinase and t-PA were given as a bolus dose of 15,000 U/kg. There was no detectable circulating fibrinolytic activity 30 minutes after the bolus dose of t-PA and 120 minutes after the bolus dose of streptokinase. The t-PA injection produced 34% thrombolysis at 30 minutes, 90% thrombolysis at 120 minutes, and 96% thrombolysis at 240 minutes. The streptokinase injection produced 17% thrombolysis at 30 minutes, 34% at 120 minutes, and 34% at 240 minutes. These observations indicate that the thrombolytic effect of t-PA is sustained beyond its time of clearance from the circulation whereas the thrombolytic effect of streptokinase closely parallels its activity in the circulation

175

Enhanced levels of urokinase plasminogen activator and its soluble receptor in common variable immunodeficiency  

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Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by defective immunoglobulin production and high frequency of bacterial infections, autoimmunity and manifestations of chronic inflammation. The urokinase plasminogen activator (uPA), its cell bound and soluble receptor (uPAR, suPAR) have complex biological functions involving innate immune defense mechanisms and regulation of inflammation. Based on this dual role, we hypothesized that the uPA system could be affected in CVID, and examined expression of components of the uPA system in subgroups of CVID. All CVID-patients had increased plasma levels of suPAR with particularly high levels in those with splenomegaly and thrombocytopenia. Plasma uPA levels were also raised in these patients, and both suPAR and uPA levels correlated with the monocyte activation marker neopterin. Monocytes from CVID patients had increased expression of uPAR. We show an increased activation of the uPA system possibly contributing to the inflammatory phenotype seen in subgroups of CVID patients.

Fevang, BØrre; Eugen-Olsen, Jesper

2009-01-01

176

Elevated levels of plasminogen activators in the pathogenesis of delayed radiation damage in rat cervical spinal cord in vivo  

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The pathophysiology of the cellular basis of radiation-induced demyelination and white-matter necrosis of the central nervous system (CNS) is poorly understood. Preliminary data suggest that tissue damage is partly mediated through changes in the proteolytic enzymes. In this study, we irradiated rat cervical spinal cords with single doses of 24 Gy of 18 MV photons or 20 MeV electrons and measured the levels of plasminogen activators at days 2, 7, 30, 60, 90, 120, 130 and 145 after irradiation, using appropriate controls at each time. Fibrin zymography revealed fibrinolytic bands representing molecular weights of 68,000 and 48,000 in controls and irradiated samples; these bands increased significantly at days 120, 130 and 145 after irradiation. Inhibition of these enzymatic bands with specific antibodies against tissue-type plasminogen activator (tPA) and amiloride, an inhibitor for urokinase plasminogen activator (uPA), confirmed that these bands were tPA and uPA. Enzymatic levels quantified by densitometry showed a twofold elevation in the levels of tPA and more than a tenfold increase in uPA after 120 days' irradiation. Activity of uPA was increased threefold by day 2 and increased steadily with time compared to nonirradiated control samples. Enzyme-linked immunosorbent assay (ELISA) also showed a threefold increase in the tPA content in the extracts of irradiated rat cervical spinal cords at days 120, 130 and 145. This study adds additional information to the propoy adds additional information to the proposed role of plasminogen activators in the pathogenic pathways of radiation damage in the CNS. 38 refs., 6 figs

177

Synthesis and evaluation of non-basic inhibitors of urokinase-type plasminogen activator (uPA).  

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Recent drug discovery programs targeting urokinase plasminogen activator (uPA) have resulted in nonpeptidic inhibitors consisting of amidine or guanidine functional groups attached to aromatic or heteroaromatic scaffolds. There is a general problem of poor oral bioavailability of these charged inhibitors. In this paper, we report the synthesis and evaluation of a series of naphthamide and naphthalene sulfonamides as uPA inhibitors containing non-basic groups as substitute for amidine or guanidine groups. PMID:22285569

Venkatraj, Muthusamy; Messagie, Jonas; Joossens, Jurgen; Lambeir, Anne-Marie; Haemers, Achiel; Van der Veken, Pieter; Augustyns, Koen

2012-02-15

178

Cloning and Expression of a Human Tissue Plasminogen Activator Variant:K2S in Escherichia coli  

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Full Text Available The DNA sequence of Kringle-2 and serine protease domains of the human tissue plasminogen activator (reteplase, K2S was PCR amplified. This product was then cloned into the expression vector pET15b plasmid. The presence of the insert was confirmed by restriction digestion, PCR and determination of the nucleotide sequence. By using isopropyl ?-D thiogalactopyranoside (IPTG, reteplase was induced in E. coli BL21 cells and analyzed using polyacrylamide gel electrophoresis (PAGE.

Hamid Mir Mohammad Sadeghi

2007-01-01

179

Successful thrombolysis using recombinant tissue plasminogen activator in cases of severe pulmonary embolism with mobile thrombi in the right atrium  

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Hereby, we report two cases of acute pulmonary embolism with concomitant right-sided thrombus, which were successfully treated using recombinant tissue plasminogen activator (rtPA). These patients had life-threatening acute right ventricular failure, which dramatically improved within hours following thrombolysis. These cases emphasize the clinical utility of rtPA for the treatment of life-threatening pulmonary embolism. PMID:24936311

Durakoglugil, Murtaza Emre; Ugurlu, Yavuz; Sahin, Ismail; Dogan, Sitki; Ergul, Elif; Karadag, Zakir; Bostan, Mehmet

2014-01-01

180

Angiotensin I-converting-enzyme (ACE)-inhibitory activity of tryptic peptides of ovine $\\beta$-lactoglobulin and of milk yoghurts obtained by using different starters  

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The aim of this study was to investigate the angiotensin I-converting-enzyme (ACE)-inhibitory activity of tryptic hydrolysates of ovine $\\beta$-lactoglobulin, and of yoghurts made by using different starters. Ovine $\\beta$-lactoglobulin (a mixture of variants A and B at a ratio of 50/50) was subjected to trypsin activity. The degree of hydrolysis of native whole $\\beta$-lactoglobulin reached 56, 72, 93 and 95% after 1, 2, 8 and 24 h, respectively. ACE-inhibitory activity of tryptic hydrolysat...

Chobert, Jean-marc; El-zahar, Khaled; Sitohy, Mahmoud; Dalgalarrondo, Miche?le; Me?tro, Franc?ois; Choiset, Yvan; Haertle?, Thomas

2005-01-01

 
 
 
 
181

Age-dependent neonatal intracerebral hemorrhage in plasminogen activator inhibitor 1 knockout mice.  

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Intracerebral-intraventricular hemorrhages (ICH/IVH) in very preterm neonates are responsible for high mortality and subsequent disabilities. In humans, tissue plasminogen activator (t-PA) initiates fibrinolysis and activates endoluminal-endothelial receptors; dysfunction of the t-PA inhibitor (PAI-1) results in recurrent hemorrhages. We used PAI-1 knockout (PAI-1) mice to examine the role of t-PA in age-dependent intracranial hemorrhages as a possible model of preterm ICH/IVH. Intracortical injection of 2 ?L of phosphate-buffered saline produced a small traumatic injury and a high rate of hemorrhage in PAI-1 pups at postnatal day 3 (P3) or P5, whereas it had no effect in wild-type neonates. This resulted in white matter and cortical lesions, ventricle enlargement, hyperlocomotion, and altered cortical levels of serotonin and dopamine in the adult PAI mice. N-methyl-D-aspartate receptor blockers, plasmin- and matrix metalloproteinases inhibitors reduced hemorrhage and tissue lesions. In contrast to P3 to P5, no significant hemorrhages were induced in P10 PAI-1 pups and there were no behavioral or neurochemical alterations in adulthood. These data suggest that microvascular immaturity up to P5 in mice is a determinant factor required for t-PA-dependent vascular rupture. Neonatal PAI-1 mice could be a useful ICH/IVH model for studying the ontogenic window of vascular immaturity and vascular protection against later neurodisabilities. PMID:24709679

Leroux, Philippe; Omouendze, Priscilla L; Roy, Vincent; Dourmap, Nathalie; Gonzalez, Bruno J; Brasse-Lagnel, Carole; Carmeliet, Peter; Leroux-Nicollet, Isabelle; Marret, Stéphane

2014-05-01

182

SIRT1-mediated epigenetic downregulation of plasminogen activator inhibitor-1 prevents vascular endothelial replicative senescence.  

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The inactivation of plasminogen activator inhibitor-1 (PAI-1) has been shown to exert beneficial effects in age-related vascular diseases. Limited information is available on the molecular mechanisms regarding the negatively regulated expression of PAI-1 in the vascular system. In this study, we observed an inverse correlation between SIRT1, a class III histone deacetylase, and PAI-1 expression in human atherosclerotic plaques and the aortas of old mice, suggesting that internal negative regulation exists between SIRT1 and PAI-1. SIRT1 overexpression reversed the increased PAI-1 expression in senescent human umbilical vein endothelial cells (HUVECs) and aortas of old mice, accompanied by decreased SA-?-gal activity in vitro and improved endothelial function and reduced arterial stiffness in vivo. Moreover, the SIRT1-mediated inhibition of PAI-1 expression exerted an antisenescence effect in HUVECs. Furthermore, we demonstrated that SIRT1 is able to bind to the PAI-1 promoter, resulting in a decrease in the acetylation of histone H4 lysine 16 (H4K16) on the PAI-1 promoter region. Thus, our findings suggest that the SIRT1-mediated epigenetic inhibition of PAI-1 expression exerts a protective effect in vascular endothelial senescence. PMID:25040736

Wan, Yan-Zhen; Gao, Peng; Zhou, Shuang; Zhang, Zhu-Qin; Hao, De-Long; Lian, Li-Shan; Li, Yong-Jun; Chen, Hou-Zao; Liu, De-Pei

2014-10-01

183

Use of tissue plasminogen activator for thrombolysis in occluded peritoneal dialysis catheters in children.  

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Peritoneal dialysis is often the renal replacement therapy of choice in pediatric patients, but the smaller catheters are at high risk for occlusion by fibrin clots. Tissue-type plasminogen activator (t-PA) is a recombinant protease specific for fibrin, and has been shown to be an effective thrombolytic for central venous catheters. The present study aimed to demonstrate the effectiveness of t-PA for thrombolysis in occluded peritoneal catheters. Six patients between 3 weeks and 15 years of age presented with 7 episodes of occluded peritoneal catheters. In all cases, t-PA (2 mg in 40 mL normal saline) was instilled into the catheter. Patency was assessed after 60 minutes by rapid instillation and drainage of 10 mL dialysis solution per kilogram patient body weight. Thrombolysis was effective in 4 of 7 attempts. In 2 cases, occlusion occurred in the setting of acute peritonitis. In 2 cases, catheters required surgical replacement. One child developed a leak at the catheter exit site within 24 hours after treatment. No intraperitoneal bleeding was observed, and no changes were observed in systemic coagulation indices [prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen degradation products (FDP), and fibrinogen] assessed pre- and post-thrombolysis. In cases of occluded PD catheters, t-PA appears to be an effective and safe treatment. PMID:11510286

Shea, M; Hmiel, S P; Beck, A M

2001-01-01

184

Expression of the recombinant plasminogen activator (reteplase) by a non-lytic insect cell expression system.  

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Reteplase is a potent thrombolytic agent which is widely used in the management of acute myocardial infarction and stroke. It belongs to the third generation of the thrombolytic drugs and has been derived from native human tissue plasminogen activator by removing three domains of it and keeping the Kringle 2 and Serine protease domains. However, the high cost of this drug, has limited the application of this drug especially in the developing and third world countries. The most laborious steps in the bacterial production of this drug is its purification and refolding steps which keep the process yield low and the cost high. Therefore, in the present study we evaluated the expression of reteplase by a non-lytic insect cell expression system. Following cloning and transfection procedures, recombinant Sf9 insect cell clones expressing the reteplase protein were selected. Primarily, the expression was verified by dot-blot analysis and subsequently it was confirmed by Western Blotting showing a band of about 45 kD on nitrocellulose membrane. The biological activity of the expressed protein was also evaluated and showed to be about 29 IU/ml. This confirmed the possibility of expression and the correct folding of the expressed protein. Hence, optimization of the expression followed by purification of the protein could be the next steps of the study. PMID:24459471

Aflakiyan, S; Sadeghi, H Mir Mohammad; Shokrgozar, M; Rabbani, M; Bouzari, S; Jahanian-Najafabadi, A

2013-01-01

185

Identification of multiple linear epitopes of the plasminogen activator A (PauA) of Streptococcus uberis with murine monoclonal antibodies.  

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Streptococcus (S.) uberis is a common cause of mastitis in cattle. A protein (PauA) secreted by this bacterium is capable of activating plasminogen from sheep and cattle. The PauA first binds to bovine plasminogen (b-plg) to form a PauA-plasminogen complex that subsequently binds to and activates b-plg to form plasmin. We have identified several linear epitopes of PauA that are recognized by murine monoclonal antibodies to PauA. Two of the monoclonal antibodies which neutralized the enzymatic activity of PauA, EC3 and 2.22, recognized common linear peptide sequences with similar charge and spacing patterns. These neutralization epitopes are located in the predicted alpha-domain of the PauA molecule. Further, these same epitopes are in critical structure/function domains identified in other studies. These characterizations may facilitate the design of an efficacious vaccine for streptococcal mastitis in the dairy cow. PMID:15734536

McVey, D Scott; Shi, Jishu; Leigh, James A; Rosey, Everett L; Ward, Philip N; Field, Terence R; Yancey, Robert J

2005-04-01

186

Full Time Course Kinetics of the Streptokinase-Plasminogen Activation Pathway*  

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Our previously hypothesized mechanism for the pathway of plasminogen (Pg) activation by streptokinase (SK) was tested by the use of full time course kinetics. Three discontinuous chromogenic substrate initial rate assays were developed with different quenching conditions that enabled quantitation of the time courses of Pg depletion, plasmin (Pm) formation, transient formation of the conformationally activated SK·Pg* catalytic complex intermediate, formation of the SK·Pm catalytic complex, and the free concentrations of Pg, Pm, and SK. Analysis of full time courses of Pg activation by five concentrations of SK along with activity-based titrations of SK·Pg* and SK·Pm formation yielded rate and dissociation constants within 2-fold of those determined previously by continuous measurement of parabolic chromogenic substrate hydrolysis and fluorescence-based equilibrium binding. The results obtained with orthogonal assays provide independent support for a mechanism in which the conformationally activated SK·Pg* complex catalyzes an initial cycle of Pg proteolytic conversion to Pm that acts as a trigger. Higher affinity binding of the formed Pm to SK outcompetes Pg binding, terminating the trigger cycle and initiating the bullet catalytic cycle by the SK·Pm complex that converts the residual Pg into Pm. The new assays can be adapted to quantitate SK-Pg activation in the context of SK- or Pg-directed inhibitors, effectors, and SK allelic variants. To support this, we show for the first time with an assay specific for SK·Pg* that fibrinogen forms a ternary SK·Pg*·fibrinogen complex, which assembles with 200-fold enhanced SK·Pg* affinity, signaled by a perturbation of the SK·Pg* active site. PMID:23970549

Nolan, Miranda; Bouldin, Samantha D.; Bock, Paul E.

2013-01-01

187

Tissue-type plasminogen activator deficiency delays bone repair: roles of osteoblastic proliferation and vascular endothelial growth factor.  

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Further development in research of bone regeneration is necessary to meet the clinical demand for bone reconstruction. Recently, we reported that plasminogen is crucial for bone repair through enhancement of vessel formation. However, the details of the role of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) in the bone repair process still remain unknown. Herein, we examined the effects of plasminogen activators on bone repair after a femoral bone defect using tPA-deficient (tPA(-/-)) and uPA-deficient (uPA(-/-)) mice. Bone repair of the femur was delayed in tPA(-/-) mice, unlike that in wild-type (tPA(+/+)) mice. Conversely, the bone repair was comparable between wild-type (uPA(+/+)) and uPA(-/-) mice. The number of proliferative osteoblasts was decreased at the site of bone damage in tPA(-/-) mice. Moreover, the proliferation of primary calvarial osteoblasts was reduced in tPA(-/-) mice. Recombinant tPA facilitated the proliferation of mouse osteoblastic MC3T3-E1 cells. The proliferation enhanced by tPA was antagonized by the inhibition of endogenous annexin 2 by siRNA and by the inhibition of extracellular signal-regulated kinase (ERK)1/2 phosphorylation in MC3T3-E1 cells. Vessel formation as well as the levels of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1? (HIF-1?) were decreased at the damaged site in tPA(-/-) mice. Our results provide novel evidence that tPA is crucial for bone repair through the facilitation of osteoblast proliferation related to annexin 2 and ERK1/2 as well as enhancement of vessel formation related to VEGF and HIF-1? at the site of bone damage. PMID:24918201

Kawao, Naoyuki; Tamura, Yukinori; Okumoto, Katsumi; Yano, Masato; Okada, Kiyotaka; Matsuo, Osamu; Kaji, Hiroshi

2014-08-01

188

Immunohistochemically identifiable tissue plasminogen activator in cavernous angioma: mechanism for re-hemorrhage and lesion growth.  

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The mechanisms governing growth of cavernous angiomas of the brain and their propensity to hemorrhage remain unknown. Repetitive hemorrhage with neovascularization during clot organization and maturation of new vessels into a larger cavernous angioma has been hypothesized as one mechanism. This hypothesis is largely based on the histopathological similarity between the organizing clot surrounding cavernous malformations and the organizing phase of the membranes surrounding chronic subdural hematoma. The presence of tissue plasminogen activator (TPA) in the vascular endothelium of vessels contained within chronic subdural membranes has been used to argue that an intrinsic thrombolytic process is responsible, in part, for rebleeding within chronic subdural cavities. By analogy, we sought to identify whether TPA is located in tissues in and around cavernous angiomas. Cavernous malformations, surgically removed and pathologically confirmed by standard staining techniques, were immunohistochemically stained for TPA. Eleven of thirteen lesions (85%) studied contained vascular endothelial cells which stained for TPA. Of the 2 lesions which did not contain TPA, 1 was non-hemorrhagic and calcified; 7 of 11 (64%) lesions which contained TPA presented clinically with hemorrhage. These data support the hypothesis that a local thrombolytic process may be responsible for the frequent hemorrhagic nature of cavernous angiomas. Alternatively, since local elaboration of TPA is common to both chronic subdural membranes and cavernous angiomas, this finding may represent a more global characteristic of fibrinolytic homeostasis in cerebral tissues. PMID:9144712

Frim, D M; Zec, N; Golden, J; Scott, R M

1996-09-01

189

The myofibroblast is the predominant plasminogen activator inhibitor-1-expressing cell type in human breast carcinomas  

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The tumor level of plasminogen activator inhibitor-1 (PAI-1) is an informative biochemical marker of a poor prognosis in several cancer types. However, the tumor biological functions of PAI-1 and the identity of PAI-1-expressing cells are controversial. With the aim of immunohistochemically localizing PAI-1 in formalin-fixed, paraffin-embedded invasive ductal breast carcinoma samples, we raised new polyclonal antibodies against PAI-1 from different expression systems. The antibodies were affinity purified by absorption on immobilized preparations of PAI-1 different from those used for immunization. The specificity of the antibodies was ensured by immunoblotting analysis. In immunohistochemistry, the staining pattern obtained with the antibodies showed a good correlation with the PAI-1 mRNA expression pattern. In all 25 cases analyzed, PAI-1 immunoreactivity was predominantly localized in fibroblast-like cells. Double-immunofluorescence analyses showed co-expression of PAI-1 and alpha-smooth muscle actin in these cells, suggesting that they are myofibroblasts. PAI-1 was also seen in some myoepithelial cells surrounding occasional foci of ductal carcinoma in situ (9 of 25), some endothelial cells (8 of 25), some cancer cells (3 of 25), and some mast cells (6 of 25). In conclusion, we have provided a robust immunohistochemical procedure for detection of PAI-1 and shown that the majority of the PAI-1-expressing cells in invasive ductal breast carcinomas are myofibroblasts.

Offersen, Birgitte Vrou; Nielsen, Boye Schnack

2003-01-01

190

Pericyte protection by edaravone after tissue plasminogen activator treatment in rat cerebral ischemia.  

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Pericytes play a pivotal role in contraction, mediating inflammation and regulation of blood flow in the brain. In this study, changes of pericytes in the neurovascular unit (NVU) were examined in relation to the effects of exogenous tissue plasminogen activator (tPA) and a free radical scavenger, edaravone. Immunohistochemistry and Western blot analyses showed that the overlap between platelet-derived growth factor receptor ?-positive pericytes and N-acetylglucosamine oligomers (NAGO)-positive endothelial cells increased significantly at 4 days after 90 min of transient middle cerebral artery occlusion (tMCAO). The number of pericytes and the overlap with NAGO decreased with tPA but recovered with edaravone 4 days after tMCAO with proliferation. Thus, tPA treatment damaged pericytes, resulting in the detachment from astrocytes and a decrease in glial cell line-derived neurotrophic factor secretion. However, treatment with edaravone greatly improved tPA-induced damage to pericytes. The present study demonstrates that exogenous tPA strongly damages pericytes and destroys the integrity of the NVU, but edaravone treatment can greatly ameliorate such damage after acute cerebral ischemia in rats. PMID:24938625

Deguchi, Kentaro; Liu, Ning; Liu, Wentao; Omote, Yoshio; Kono, Syoichiro; Yunoki, Taijun; Deguchi, Shoko; Yamashita, Toru; Ikeda, Yoshio; Abe, Koji

2014-11-01

191

Effects of sulfonylureas on the synthesis and secretion of plasminogen activator from bovine aortic endothelial cells.  

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The effects of sulfonylureas on the production of plasminogen activator (PA) and antiactivator (PAI) were investigated using bovine aortic endothelial cells. All compounds studied stimulated PA release (1.3- to 5.2-fold), with glipizide being the most potent, followed by tolazamide, chlorpropamide, and tolbutamide, in that order, while glyburide was the least effective. Both tissue-type and urokinase-type PA production was enhanced. Studies using metabolic inhibitors indicated that both RNA and protein syntheses are required for the sulfonylurea-mediated stimulation of PA release. In addition to continuous release of the two PAs, there was also a continuous release of a single PAI, which did not show an increase after the sulfonylureas. These results suggest that, in addition to their beneficial effects in the treatment of diabetes mellitus, some sulfonylurea compounds may also have significant thrombolytic effects. These results also suggest that pharmacological enhancement of PA production by vascular endothelial cells may be a promising antithrombotic mechanism. PMID:3125227

Kuo, B S; Korner, G; Bjornsson, T D

1988-03-01

192

Relationship between expression of urokinase-type plasminogen activator and tumor angiogenesis in epithelial ovarian carcinoma  

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Full Text Available Objective To explore the expression of urokinase-type plasminogen activator(uPA in epithelial ovarian carcinoma(EOC and the relationship of the expression to microvessel density.Methods SP immunohistochemical staining was performed to determine the expression of uPA in ovarian cancer(85 cases,borderline ovarian tumor(16 cases,benign ovarian tumor(39 cases and normal ovarian tissue(24 cases.Microvessels in ovarian cancer were marked by CD34,and microvessel density(MVD was determined by direct count.The relationship between uPA and MVD was analyzed.The 85 patients with epithelial ovarian cancer were followed up.Results The highest positive rate of uPA existed in the patients with EOC.There was a correlation between the expression of uPA and MVD and the differentiation of EOC,clinical stage,lymphatic metastasis,omental metastasis,and 5 years survival rate.A significant positive correlation was found between the expression of uPA in EOC and MVD(r=0.56,P=0.02.Conclusion uPA may promote the angiogenesis of EOC,and participate in the occurrence,development,invasion and metastasis of ovarian cancer.The detection of uPA and MVD may be used as an indicator of biological behaviors and prognosis of ovarian cancer.

Ping NAN

2011-06-01

193

Angiotensinogen and Plasminogen Activator Inhibitor-1 Gene Polymorphism in Relation to Renovascular Disease  

International Nuclear Information System (INIS)

The present study was designed to evaluate angiotensinogen (AGT) M235T and plasminogen activator inhibitor-1 (PAI-1) (4G/5G) polymorphisims in relation to the occurrence of atherosclerotic renal artery stenosis (ARAS) and recurrent stenosis. In this study, 30 patients were enrolled after angiographic demonstration of ARAS; 100 healthy subjects for AGT polymorphism and 80 healthy subjects for PAI-1 polymorphism were considered the control group. The patients were followed for a mean 46.1 ± 9.2 months. The patients had significantly higher frequencies of the MT genotype and the T allele than control group (?2 = 18.2, p 2 = 11.5 p 2= 2.45, p = 0.29 and ?2 = 0.019, p = 0.89). There were no significant differences in the genotype and allele findings for the patients with and without restenosis (p > 0.05). The C-reactive protein (CRP) level was higher in the patients with restenosis than in the patients without restenosis (7.694 ± 0.39 mg/L and 1.56 ± 1.08 mg/L) (p = 0.001). Our results suggest that the M235T MT genotype and T allele might be associated with increased risk of atherosclerotic renal artery stenosis. The CRP level might be an independent predictor for recurrent stenosis

194

Binding of tissue plasminogen activator to human umbilical vein endothelial cells  

International Nuclear Information System (INIS)

The binding of purified, recombinant tissue plasminogen activator (tPA) to human umbilical vein endothelial cells (HUVEC) was studied in vitro using immunofluorescence as well as radiolabeled tPA. Immunofluorescence was performed on HUVEC grown on round glass coverslips using rabbit anti-human tPA and fluorescein-conjugated anti-rabbit immunoglobulin. Positive fluorescence was observed only after incubation of HUVEC with tPA. HUVEC were grown to confluence in 24-well tissue culture plates, washed, and incubated with a constant amount of 125I-tPA and various concentrations of unlabeled tPA. The binding of tPA to HUVEC was found to be specific, saturable, and reversible. Scatchard analysis yielded as equilibrium constant (K/sub eq/) of 4.2 x 106 M-1 and 1.2 x 107 binding sites per cell. Binding was inhibited by positively charged amino acids and by D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone but not by carbohydrates including mannose, galactose, N-acetyl glucosamine and N-acetyl galactosamine. Neat human plasma abrogates but does not totally inhibit binding of tPA to HUVEC. Binding was neither enhanced nor inhibited by fibronectin. Although the affinity of binding of tPA to HUVEC is low, the endothelial cell may be involved in regulating plasma levels of tPA in vivo which may have therapeutic significance

195

Induction of plasminogen activator by UV light in normal and xeroderma pigmentosum fibroblasts  

International Nuclear Information System (INIS)

Normal and DNA repair-deficient human fibroblasts have been used to study induction of plasminogen activator (PA) by DNA damage. UV light induced the synthesis of PA in skin fibroblasts of all types of xeroderma pigmentosum (XP) in XP heterozygotes and in human amniotic cells. Enzyme induction was, however, not observed in fibroblasts of normal adults. In classical XP, which are deficient in excision repair, PA synthesis occurred in a narrow range of low-UV fluences. In such strains, the level of enzyme produced was correlated with the extent of repair deficiency. UV fluences required for PA induction in XP variants and XP heteozygotes were at least 10 times those inducing enzyme synthesis in excision-deficient XP. Maximum enzyme induction occurred 48 hr after irradiation, and the highest levels of enzyme produced were 15-20 times those of PA baseline levels. Electrophoretic analysis showed that UV irradiation enhances the synthesis of the M/sub r/ 60,000 human urokinase-type PA, which is present in low amounts in untreated cells. Our results suggest that PA induction in human cells is caused by unrepaired DNA damage and represents a eukaryotic SOS-like function. In addition, PA induction may provide a sensitive assay for detection of cellular DNA repair deficiencies and identification of XP heterozygotes

196

ADAM9 Promotes Lung Cancer Metastases to Brain by a Plasminogen Activator-Based Pathway.  

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The transmembrane cell adhesion protein ADAM9 has been implicated in cancer cell migration and lung cancer metastasis to the brain, but the underpinning mechanisms are unclear and clinical support has been lacking. Here, we demonstrate that ADAM9 enhances the ability of tissue plasminogen activator (tPA) to cleave and stimulate the function of the promigratory protein CDCP1 to promote lung metastasis. Blocking this mechanism of cancer cell migration prolonged survival in tumor-bearing mice and cooperated with dexamethasone and dasatinib (a dual Src/Abl kinase inhibitor) treatment to enhance cytotoxic treatment. In clinical specimens, high levels of ADAM9 and CDCP1 correlated with poor prognosis and high risk of mortality in patients with lung cancer. Moreover, ADAM9 levels in brain metastases derived from lung tumors were relatively higher than the levels observed in primary lung tumors. Our results show how ADAM9 regulates lung cancer metastasis to the brain by facilitating the tPA-mediated cleavage of CDCP1, with potential implications to target this network as a strategy to prevent or treat brain metastatic disease. Cancer Res; 74(18); 5229-43. ©2014 AACR. PMID:25060522

Lin, Chen-Yuan; Chen, Hung-Jen; Huang, Cheng-Chung; Lai, Liang-Chuan; Lu, Tzu-Pin; Tseng, Guan-Chin; Kuo, Ting-Ting; Kuok, Qian-Yu; Hsu, Jennifer L; Sung, Shian-Ying; Hung, Mien-Chie; Sher, Yuh-Pyng

2014-09-15

197

Extracellular proteolysis of reelin by tissue plasminogen activator following synaptic potentiation.  

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The secreted glycoprotein reelin plays an indispensable role in neuronal migration during development and in regulating adult synaptic functions. The upstream mechanisms responsible for initiating and regulating the duration and magnitude of reelin signaling are largely unknown. Here we report that reelin is cleaved between EGF-like repeats 6-7 (R6-7) by tissue plasminogen activator (tPA) under cell-free conditions. No changes were detected in the level of reelin and its fragments in the brains of tPA knockouts, implying that other unknown proteases are responsible for generating reelin fragments found constitutively in the adult brain. Induction of NMDAR-independent long-term potentiation with the potassium channel blocker tetraethylammonium chloride (TEA-Cl) led to a specific up-regulation of reelin processing at R6-7 in wild-type mice. In contrast, no changes in reelin expression and processing were observed in tPA knockouts following TEA-Cl treatment. These results demonstrate that synaptic potentiation results in tPA-dependent reelin processing and suggest that extracellular proteolysis of reelin may regulate reelin signaling in the adult brain. PMID:24892761

Trotter, J H; Lussier, A L; Psilos, K E; Mahoney, H L; Sponaugle, A E; Hoe, H-S; Rebeck, G W; Weeber, E J

2014-08-22

198

Acute myocardial infarction following intravenous tissue plasminogen activator for acute ischemic stroke: An unknown danger  

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Full Text Available Thrombolysis with intravenous tissue (IV plasminogen activator (tPA is considered for patients with acute ischemic stroke falling within the described inclusion criteria defined by The National Institute of Neurological Disorders and Stroke (NINDS rtPA trial. Complications of IV thrombolysis with tPA are commonly related to hemorrhage, anaphylaxis, or arterial occlusion. We describe two cases of acute myocardial infarction (MI following IV tPA infusion for acute stroke. One of the patients had underlying ischemic heart disease (IHD while the other did not have any prior IHD. Both had presented with acute ischemic stroke within the window period of thrombolysis and had no contraindications for thrombolysis. Both the patients succumbed due to myocardial infarction and cardiovascular collapse due to new onset arrhythmias. Acute MI immediately following IV tPA for stroke is a rare but serious complication. The disruption of intracardiac thrombus and subsequent embolization to coronary arteries may be an important mechanism in the occurrence of MI after administration of tPA for acute ischemic stroke. As both the patients succumbed before the arrangement for coronary angiography, the demonstration of intracardiac or intracoronary thrombus was not possible. But clinically, the presence of chest pain with elevated troponin levels and ST segment elevation pointed to MI. We suspect that fragmentation and lysis of intracardiac thrombus may result in MI after use of tPA for acute ischemic stroke, though the remote possibility of simultaneous occurrence of two atherosclerotic events MI and stroke exists.

Adatia Sweta

2010-01-01

199

Pneumatic Displacement of a Dense Submacular Hemorrhage with or without Tissue Plasminogen Activator  

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Full Text Available Background: To evaluate the efficacy of treating a dense submacular hemorrhage withpneumatic displacement with or without tissue plasminogen activator (tPA.Methods: Twenty-four patients with a dense submacular hemorrhage were treated withintravitreal expansile gas, with or without an intravitreal injection of tPA, inorder to displace the submacular blood. The main outcome measurementsinclude preoperative and postoperative visual acuity, postoperative fluoresceinangiography (FAG results and additional postoperative treatments.Results: Total or subtotal subfoveal blood displacement was achieved in all 24 eyes.After a mean follow-up of 15.5 months (range 6-50 months, final visualacuity had improved two or more lines in 11 (45.8% of the 24 eyes, andmeasured 20/100 or better in 10 (4l.7% of the 11 eyes. Based on the FAGresults for 14 cases, nine eyes (64.3% received additional postoperativelaser treatment. Final visual acuity of 20/100 or better was achieved in four(40% of the 10 eyes, with a choroidal neovascular membrane (CNVMdetected on FAG, and dye leakage not detected in three (75% of the foureyes.Conclusions: Pneumatic displacement, with or without intravitreal injection of tPA, seemsuseful in displacing dense submacular hemorrhage and facilitating visualimprovement, although the visual result is often limited by the progression ofthe underlying macular disease. In patients with age-related macular degeneration,more treatable CNVM may be detected on postoperative FAG.

Po-Min Yang

2005-12-01

200

Fatty acids differentially modify the expression of urokinase type plasminogen activator receptor in monocytes.  

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The urokinase plasminogen activator system with its receptor uPAR contributes to the migratory potential of macrophages, a key event in atherosclerosis. We here investigated whether free fatty acids (FFA) modify the expression for uPAR in the PMA-differentiated human monocyte/macrophage-like cell line U937. Two hundred micromolar palmitate induced a threefold increase of the uPAR mRNA expression. Although the mono- and polyunsaturated fatty acids oleate and linoleate also stimulated uPAR expression, oleate had a significantly lower effect than palmitate. The observed effects were time and dose dependent. Inhibition of PKC-and ERK-pathways resulted in a strong down-regulation of basal uPAR expression whereas the FFA induced up-regulation remained unchanged. In contrast, FFA induced uPAR up-regulation was abolished by the specific inhibition of p38 MAPK. In conclusion we demonstrate that uPAR expression in human monocytes/macrophages is differentially stimulated by FFA. These effects are partially mediated by the p38 MAP-kinase signaling pathway. PMID:18762175

Assmann, Anke; Möhlig, Matthias; Osterhoff, Martin; Pfeiffer, Andreas F H; Spranger, Joachim

2008-11-01

 
 
 
 
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Recombinant tissue-plasminogen activator-induced thrombolysis after cerebral thromboembolism in mice.  

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The effects of intracarotid thrombolysis with recombinant tissue-plasminogen activator (rt-PA) on cerebral laser Doppler flow (LDF) and the degree of ischemic injury, as revealed by triphenyltetrazolium chloride (TTC) staining, were studied 24 h following cerebral thromboembolism in mice. Thromboembolization with fibrin-rich clot material (0.28-microl clot volume) led to an LDF decline to about 20-30% of baseline in untreated mice, which resulted in reproducible infarcts of the middle cerebral artery (MCA) territory (122.8 +/- 29.4 mm(3)). Administration of rt-PA (10 mg/kg) 15 min after clot injection induced a progressive LDF restoration to approximately 115% of control values after 2 h, and brought about a significant reduction of the infarct volume (62.3 +/- 42.4 mm(3)). Our results indicate that ischemic injury may be significantly attenuated by intracarotid thrombolysis. However, injury is not completely reversed, even if reperfusion is initiated as early as 15 min after embolization. PMID:10663962

Kilic, E; Hermann, D M; Hossmann, K A

2000-03-01

202

Is vascular imaging valuable prior to administration of intravenous tissue plasminogen activator?  

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Our goals were to explore whether performing computerized tomography angiography (CTA) prior to administration of tissue plasminogen activator (tPA) delays treatment and impacts outcome in patients with proximal middle cerebral artery occlusions (pMCAO). Patients with pMCAO with a National Institutes of Health Stroke scale (NIHSS) score >10 were identified from a prospective Stroke Registry. Patients underwent multi-parametric imaging studies whenever possible. Patients who underwent CTA were compared to those who only had non-contrast CT scan. Disability was measured with the modified Rankin Scale. Logistic regression was used to determine outcome modifiers. We included 73 patients (median age 73years, 52% men) with moderate-severe stroke (median admission NIHSS 14). Of those, 44 underwent CTA and 29 did not. There were no differences between the groups in risk factor profile or baseline characteristics including stroke severity and door to needle, door to imaging or imaging to treatment times. At 90days post-stroke there were no statistically significant differences in outcomes between the groups. On multivariate analysis, performing CTA had no impact on the chance of obtaining favorable outcome. In conclusion, CTA does not have a major impact on outcome in patients with pMCAO treated with tPA. Therefore, performing CTA should be considered on an individual basis prior to administration of tPA. PMID:24874695

Eichel, Roni; Cohen, Jose E; Gomori, John M; Ben-Hur, Tamir; Keigler, Galina; Leker, Ronen R

2014-10-01

203

Dissociation of severity of stroke and aphasia recovery early after intravenous recombinant tissue plasminogen activator thrombolysis.  

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Clinical observation suggested to us that aphasia recovers relatively better than other deficits early after intravenous recombinant tissue plasminogen activator (IV-rtPA) treatment in stroke patients with minor deficits, while the reverse seemed the case in those with severe deficits. Retrospective analysis of acute ischemic stroke patients with aphasia admitted within 3hours from symptom onset and treated with IV-rtPA was carried out. Stroke severity, aphasia and global neurological impairment were assessed at admission and 24hours after thrombolysis. Improvement of aphasia (gain of ?1 point on the National Institutes of Health Stroke Scale [NIHSS] aphasia score) and global neurological improvement (gain of ?4 points on the NIHSS) were compared in minor strokes (NIHSS ?7), moderate strokes (NIHSS 8-15), and major strokes (NIH ?16). Sixty-nine of 243 stroke patients suffered from aphasia. Improvement of aphasia occurred in 7/16 minor strokes, 11/25 moderate strokes, and 7/28 severe strokes. Improvement of ?4 points on the NIHSS occurred in 3/16 minor strokes, 17/25 moderate strokes and 15/28 severe strokes. There is a significant (X(2)=4.073, psevere strokes. This confirms the clinically suspected dissociation between a good early recovery from aphasia in minor strokes relative to recovery of other neurological deficits, as opposed to a better recovery from other neurological deficits than from aphasia in patients with severe strokes. PMID:24852905

Kremer, Christine; Kappelin, Johan; Perren, Fabienne

2014-10-01

204

Targeting plasminogen activator inhibitor-1 inhibits angiogenesis and tumor growth in a human cancer xenograft model.  

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Cancers of the urinary bladder result in aggressive and highly angiogenic tumors for which standard treatments have only limited success. Patients with advanced disease have a 5-year survival rate of less than 20%, and no new anticancer agent has been successfully introduced into the clinic armamentarium for the treatment of bladder cancer in more than 20 years. Investigations have identified plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, as being highly expressed in several malignancies, including bladder cancer, in which high expression is associated with a poor prognosis. In this study, we evaluated PAI-1 as a potential therapeutic target for bladder cancer. PAI-1 expression was manipulated in a panel of cell lines and functional inhibition was achieved using the small molecule tiplaxtinin. Reduction or inhibition of PAI-1 resulted in the reduction of cellular proliferation, cell adhesion, and colony formation, and the induction of apoptosis and anoikis in vitro. Treatment of T24 xenografts with tiplaxtinin resulted in inhibition of angiogenesis and induction of apoptosis, leading to a significant reduction in tumor growth. Similar results were obtained through evaluation of the human cervical cancer HeLa cell line, showing that PAI-1-mediated effects are not restricted to tumor cells of bladder origin. Collectively, these data show that targeting PAI-1 may be beneficial and support the notion that novel drugs such as tiplaxtinin could be investigated as anticancer agents. PMID:24072883

Gomes-Giacoia, Evan; Miyake, Makito; Goodison, Steve; Rosser, Charles J

2013-12-01

205

Aggregation and retention of human urokinase type plasminogen activator in the yeast endoplasmic reticulum  

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Full Text Available Abstract Background Secretion of recombinant proteins in yeast can be affected by their improper folding in the endoplasmic reticulum and subsequent elimination of the misfolded molecules via the endoplasmic reticulum associated protein degradation pathway. Recombinant proteins can also be degraded by the vacuolar protease complex. Human urokinase type plasminogen activator (uPA is poorly secreted by yeast but the mechanisms interfering with its secretion are largely unknown. Results We show that in Hansenula polymorpha overexpression worsens uPA secretion and stimulates its intracellular aggregation. The absence of the Golgi modifications in accumulated uPA suggests that aggregation occurs within the endoplasmic reticulum. Deletion analysis has shown that the N-terminal domains were responsible for poor uPA secretion and propensity to aggregate. Mutation abolishing N-glycosylation decreased the efficiency of uPA secretion and increased its aggregation degree. Retention of uPA in the endoplasmic reticulum stimulates its aggregation. Conclusions The data obtained demonstrate that defect of uPA secretion in yeast is related to its retention in the endoplasmic reticulum. Accumulation of uPA within the endoplasmic reticulum disturbs its proper folding and leads to formation of high molecular weight aggregates.

Smirnov Vladimir N

2002-10-01

206

Inhibitory mechanism of peptides and antibodies targeting murine urokinase-type plasminogen activator.  

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Urokinase-type plasminogen activator (uPA) is a serine protease that plays an important role in many pathophysiological processes. It is also a marker for a poor prognosis in several cancer types. In order to investigate the efficiency of uPA inhibitors which might be candidates for therapeutic drugs, a detailed mechanistic understanding must be obtained. One peptide and two antibodies were studied in this thesis. First, an engineered cyclic peptide, mupain-1-16 with an unnatural amino acid in the P1 position and the sequence CPAYS[L-3-(N-Amidino-4-piperidyl)alanine]YLDC was investigated. The high affinity and specificity of mupain-1-16 makes it a suitable inhibitor for targeting of murine uPA in order to investigate the importance of uPA in murine disease models. Secondly, two high affinity monoclonal antibodies targeting murine uPA (mU1 and mU3) were studied. These antibodies showed different conformational and inhibitory mechanisms both in vivo and in vitro. Their similar epitopes, but different functions revealed two different allosteric regulation mechanisms for antibodies binding to serine proteases. Both the peptidic inhibitors and the allosteric mechanisms of uPA are believed to be important for future tumour model studies and the development of more efficient inhibitors against uPA.

Liu, Zhuo

2012-01-01

207

Role of plasminogen activator inhibitor type-1 in radiation-induced normal tissues injury  

International Nuclear Information System (INIS)

Radiotherapy is an essential tool for cancer treatment, but there is a balance between benefits and risks related to the use of ionizing radiation: the objective is to deliver a maximum dose to the tumour to destroy or to sterilize it while protecting surrounding normal tissues. Radio-induced damages to normal tissues are therefore a limiting factor when increasing the dose delivered to the tumour. One of the objectives of this research thesis is to bring to the fore a relationship between the initiation of lesions and the development of late damages, more particularly in the intestine, and to identify the involved molecular actors and their inter-connectivity. After a first part presenting ionizing radiation, describing biological effects of ionizing radiation and their use in radiotherapy, presenting the intestine and the endothelium and discussing the intestine radio-sensitivity, discussing the radio-induced intestine damages and radiotherapy-induced complications, and presenting the plasminogen activator inhibitor (PAI-1) and its behaviour in presence of ionizing radiation, two articles are reproduced. The first one addresses the effect of a pharmacological inhibition and of genetic deficiency in PAI-1 on the evolution of radio-induced intestine lesions. The second one discusses the fact that radio-induced PAI-1-related death of endothelial cells determines the severity of early radio-induced intestine lesions

208

A human monoclonal antibody scFv to urokinase plasminogen activator.  

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A human monoclonal antibody can be a good method for tumor diagnosis and treatment. This study is aimed at the generation of human antibody fragments against urokinase plasminogen activator (uPA) known to be related to tumor metastasis using the naive human antibody phage display library. Three clones--A2, A8, and E4--were selected from 1 x 10(10) sized human naïve antibody phage library using BIAcore rescue and screen. Clone A8 was finally selected by flow cytometry against Hep3 and HT1080, uPA overexpressing tumor cell lines. A8 clone consisted of 324 bp lambda and 402 bp heavy chains. The affinity (K(D)) of purified A8 antibody fragments was 1.44 x 10(-8) M(-1). The antibody fragment was reacted with HT1080 in a dose-dependent manner but not reacted with LS513 normal fibroblast. In this study, uPA specific human monoclonal antibody fragment A8 was made with BIAcore selection. Selected A8 was bound specifically to uPA expressed on the tumor cell surface. Further study for the application of A8 antibody clones will be needed. PMID:20443707

Bae, Ki-Beom; Jeong, Young-Joo; Won, Hae Jeong; Hong, Kwan-Hee; Choi, Il-Whan; Seo, Su-Kil; Park, Sae-Gwang

2010-04-01

209

Endovascular thrombolysis for pediatric cerebral sinus venous thrombosis with tissue plasminogen activator and abciximab.  

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Cerebral sinus venous thrombosis (CSVT) is a relatively rare but potentially devastating disease. Medical management of CSVT with systemic anticoagulation has been the mainstay treatment strategy with these patients. However, some patients may not respond to this treatment or may present with very severe symptoms indicating more aggressive management strategies. The authors present the case of a pediatric patient who presented with severe CSVT, who underwent successful recanalization with endovascular tissue plasminogen activator (tPA) and abciximab. To the authors' knowledge there are no cases of endovascular thrombolysis for CSVT described in the literature in which abciximab has been used in conjunction with tPA. The authors also review the literature regarding the agents used and outcome in pediatric patients with CSVT after endovascular thrombolysis. The use of abciximab in conjunction with tPA may be considered in patients whose blood is hypercoagulable and in whom the treatment strategy is to obtain acute recanalization and long-term venous patency. However, the use of adjunctive agents increases the risk of hemorrhagic complications and must be done judiciously. PMID:24180679

Khan, Imad S; Ladner, Travis R; Satti, Komal F; Ehtesham, Moneeb; Jordan, Lori C; Singer, Robert J

2014-01-01

210

Effects of retinoids on proliferation and plasminogen activator expression in a bovine mammary epithelial cell line.  

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Effects of two natural (retinol and retinoic acid, RA) and one synthetic N-(4-hydroxyphenyl) retinamide (4-HPR) retinoids on proliferation and expression of urokinase-plasminogen activator (u-PA) by bovine mammary epithelial cells were examined. The BME-UV1 established bovine mammary epithelial cell line was used as a model system. All retinoids tested (retinol, RA and 4-HPR) were effective inhibitors of cell proliferation. When cells were cultured in the absence of fetal bovine calf serum (FBCS), inhibition occurred at concentrations as low as 1 nM for all retinoids tested. The effect of retinoids on cell proliferation was not dose-related when cells were cultured in the absence of FBCS. All retinoids (retinol, RA, 4-HPR), when used in the range 1 nM-10 microM (noncytotoxic concentrations), were equally effective and had identical inhibition patterns. Inhibition of cell proliferation by RA was apparent by 6 h and was higher after 24 h in culture. In contrast, when cells were cultured in the presence of FBCS, the effect of RA and retinol on cell proliferation was dose-related. RA and retinol inhibited cell proliferation (P0.05) on u-PA mRNA levels or u-PA activity. Furthermore, RA inhibited cell proliferation in the presence of FBCS but had no effect (P>0.05) on u-PA mRNA levels. Thus, retinoids are effective inhibitors of bovine mammary epithelial cell proliferation and this growth inhibition does not seem to correlate with any changes in u-PA mRNA or u-PA activity. PMID:14649406

Cheli, Federica; Politis, Ioannis; Rossi, Luciana; Fusi, Eleonora; Baldi, Antonella

2003-11-01

211

Tissue plasminogen activator involvement in experimental autoimmune myasthenia gravis: aggravation and therapeutic potential.  

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Tissue plasminogen activator (tPA), a component of the PA/plasmin system, is elevated in inflammatory areas and plays a role in inflammatory neurological disorders. In the present study we explored the involvement of tPA and the potential immunomodulatory activity of tPA in experimental autoimmune myasthenia gravis (EAMG). Mice deficient in tPA (tPA(-/-)) present with a markedly more severe disease than wild type EAMG mice. In an attempt to treat EAMG with an 18aa peptide derived from the PA system inhibitor (PAI-1), designed to tether out the endogenous inhibitor, a significant suppression of disease severity was demonstrated. The more severe disease in tPA(-/-) mice was accompanied by a higher level of anti-AChR antibodies and increased expression of B-cell markers. In view of the essential role of B-cell activating factor (BAFF) in B-cell maturation, the expression of BAFF family components was tested. An increase in BAFF and BAFF receptor was observed in EAMG tPA(-/-) mice, whereas BCMA expression was reduced, consistent with the increased level of pathogenic antibodies and the more severe disease. Given the importance of T regulatory cells (Tregs) in EAMG, they were evaluated and their number was reduced in tPA(-/-) mice, in which EAMG was aggravated, whereas following PAI-1dp treatment, Tregs were replenished and the disease was ameliorated. The results show the involvement of tPA in EAMG, implying a protective role for tPA in EAMG pathogenesis. The amelioration of EAMG by PAI-1dp treatment suggests that the PA system may be considered a potential site for therapeutic intervention in neuroimmune diseases. PMID:24423642

Gur-Wahnon, Devorah; Mizrachi, Tehila; Wald-Altman, Shane; Al-Roof Higazi, Abd; Brenner, Talma

2014-08-01

212

Oviduct-specific expression of tissue plasminogen activator in laying hens  

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Full Text Available Egg-laying hens are important candidate bioreactors for pharmaceutical protein production because of the amenability of their eggs for protein expression. In this study, we constructed an oviduct-specific vector containing tissue plasminogen activator (tPA protein and green fluorescent protein (pL-2.8OVtPAGFP and assessed its expression in vitro and in vivo. Oviduct epithelial and 3T3 cells were cultured and transfected with pL-2.8OVtPAGFP and pEGP-N1 (control vector, respectively. The pL-2.8OVtPAGFP vector was administered to laying hens via a wing vein and their eggs and tissues were examined for tPA expression. The oviduct-specific vector pL-2.8OVtPAGFP was expressed only in oviduct epithelial cells whereas pEGP-N1 was detected in oviduct epithelial and 3T3 cells. Western blotting detected a 89 kDa band corresponding to tPA in egg white and oviduct epithelial cells, thus confirming expression of the protein. The amount of tPAGFP in eggs ranged 9 to 41 ng/mL on the third day after vector injection. The tPA expressed in egg white and oviduct epithelial cells showed fibrinolytic activity, indicating that the protein was expressed in active form. GFP was observed only in oviducts, with no detection in heart, muscle, liver and intestine. This is the first study to report the expression of tPA in egg white and oviduct epithelial cells using an oviduct-specific vector.

Hubdar Ali Kaleri

2011-01-01

213

Optimizing production of recombinant tissue plasminogen activator in non-pathogenic Leishmania by two genetic constructs  

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Full Text Available "nBackground: Recombinant tissue plasminogen activator (rt-PA is one of the most important thrombolytic agents used in patients with vascular occlusions such as acute ischemic stroke or myocardial infarction. A variety of recombinant protein expression systems have been developed for heterologous gene expression in prokaryotic and eukaryotic hosts. In recent years, Leishmania tarentolae (L. tarentolae, a non-pathogenic trypanosomatid protozoa, has come under consideration because of its safety and immunogenicity as a vaccine vector and special attributes in the expression of complex proteins. This study was done to improve rt-PA expression in this protozoon and create the opportunity for the replacement of rt-PA gene with other genes for the production of other complex proteins."n "n Methods: Two expression cassettes were used for the integration of two copies of t-PA cDNA, one copy in each cassette, into the parasite genome by electroporation. The transformed clones were selected by antibiotic resistancy. The expression of active secreted rt-PA was confirmed by Western blot analysis and Chromolize assay."n "n Results: Appearance of a 64 kD band in nitrocellulose membrane in the Western blot analysis confirmed the presence of full-length rt-PA in the culture media. Chromolize assay showed the expression levels of active recombinant t-PA in single and double transfected L. tarentolae clones- 375 IU/ml and 480 IU/ml of the culture media, respectively."n "n Conclusion: The produced rt-PA in the culture media containing the transfected cells was at least seven times higher than what has been reported in previous studies on L. tarentolae or on some other eukaryotic systems.

Hemayatkar M

2011-02-01

214

Oviduct-specific expression of tissue plasminogen activator in laying hens  

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Full Text Available SciELO Brazil | Language: English Abstract in english Egg-laying hens are important candidate bioreactors for pharmaceutical protein production because of the amenability of their eggs for protein expression. In this study, we constructed an oviduct-specific vector containing tissue plasminogen activator (tPA) protein and green fluorescent protein (pL- [...] 2.8OVtPAGFP) and assessed its expression in vitro and in vivo. Oviduct epithelial and 3T3 cells were cultured and transfected with pL-2.8OVtPAGFP and pEGP-N1 (control vector), respectively. The pL-2.8OVtPAGFP vector was administered to laying hens via a wing vein and their eggs and tissues were examined for tPA expression. The oviduct-specific vector pL-2.8OVtPAGFP was expressed only in oviduct epithelial cells whereas pEGP-N1 was detected in oviduct epithelial and 3T3 cells. Western blotting detected a 89 kDa band corresponding to tPA in egg white and oviduct epithelial cells, thus confirming expression of the protein. The amount of tPAGFP in eggs ranged 9 to 41 ng/mL on the third day after vector injection. The tPA expressed in egg white and oviduct epithelial cells showed fibrinolytic activity, indicating that the protein was expressed in active form. GFP was observed only in oviducts, with no detection in heart, muscle, liver and intestine. This is the first study to report the expression of tPA in egg white and oviduct epithelial cells using an oviduct-specific vector.

Hubdar Ali, Kaleri; Liu, Xiang; Jueken, Aniwashi; Shiyong, Xu.

215

Biochemical mechanism of action of a diketopiperazine inactivator of plasminogen activator inhibitor-1.  

DEFF Research Database (Denmark)

XR5118 [(3 Z,6 Z )-6-benzylidine-3-(5-(2-dimethylaminoethyl-thio-))-2-(thienyl)methylene-2,5-dipiperazinedione hydrochloride] can inactivate the anti-proteolytic activity of the serpin plasminogen activator inhibitor-1 (PAI-1), a potential therapeutic target in cancer and cardiovascular diseases. Serpins inhibit their target proteases by the P(1) residue of their reactive centre loop (RCL) forming an ester bond with the active-site serine residue of the protease, followed by insertion of the RCL into the serpin's large central beta-sheet A. In the present study, we show that the RCL of XR5118-inactivated PAI-1 is inert to reaction with its target proteases and has a decreased susceptibility to non-target proteases, in spite of a generally increased proteolytic susceptibility of specific peptide bonds elsewhere in PAI-1. The properties of XR5118-inactivated PAI-1 were different from those of the so-called latent form of PAI-1. Alanine substitution of several individual residues decreased the susceptibility of PAI-1 to XR5118. The localization of these residues in the three-dimensional structure of PAI-1 suggested that the XR5118-induced inactivating conformational change requires mobility of alpha-helix F, situated above beta-sheet A, and is in agreement with the hypothesis that XR5118 binds laterally to beta-sheet A. These results improve our understanding of the unique conformational flexibility of serpins and the biochemical basis for using PAI-1 as a therapeutic target. Udgivelsesdato: 2003-Aug-1

Einholm, Anja P; Pedersen, Katrine E

2003-01-01

216

Soluble Urokinase-Type Plasminogen Activator Receptor Levels in Patients With Schizophrenia  

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BACKGROUND: The etiology of schizophrenia remains largely unknown but alterations in the immune system may be involved. In addition to the psychiatric symptoms, schizophrenia is also associated with up to 20 years reduction in life span. Soluble urokinase-type plasminogen activator receptor (suPAR) is a protein that can be measured in blood samples and reflects the levels of inflammatory activity. It has been associated with mortality and the development of type 2 diabetes and cardiovascular disease. METHODS: suPAR levels in patients with schizophrenia were compared to healthy controls from the Danish Blood Donor Study. SuPAR levels were dichotomized at >4.0 ng/ml, which is considered the threshold for low grade inflammation. A multiple logistic regression model was used and adjusted for age, sex, and current smoking. RESULTS: In total we included 1009 subjects, 105 cases with schizophrenia (10.4%) and 904 controls (89.6%). The mean suPAR values were 4.01 ng/ml (SD = 1.43) for the cases vs 1.91 ng/ml (SD = 1.35) for the controls (P 4.0 ng/ml yielded: schizophrenia, OR: 46.15 95% CI 22.69-93.87, P < .001; age, OR: 1.02 95% CI 0.99-1.02, P = .15; male sex, OR: 0.70 95% CI 0.35-1.36, P = .29; and current smoking, OR: 3.51 95% CI 1.78-6.94, P < .001. CONCLUSIONS: Patients with schizophrenia had significantly higher suPAR levels than healthy controls. Further studies are warranted to clarify if elevated suPAR levels are involved in the pathophysiology of schizophrenia and/or the increased mortality found in patients with schizophrenia.

Nielsen, Jimmi; RØge, Rasmus

2014-01-01

217

The effect of 6-aminohexanoic acid and fucoidan on the activation of glutamic plasminogen by streptokinase.  

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Studies were conducted on the effect of 6-aminohexanoic acid (6-AH) or fucoidan on the activation of glutamic plasminogen (glu-plg) by streptokinase using 0.05 mol/l Tris buffer containing a physiological concentration of NaCl. In contrast to the earlier reports where no NaCl was added to the buffer solution, addition of 6-AH enhanced the initial rate while the inhibition by fucoidan was not affected. Double reciprocal plots of the activation of glu-plg by streptokinase in the presence of 6-AH showed an increase in Vmax, but no change in Km. However, the addition of fucoidan showed a decrease in Vmax, but no change in Km. To determine whether the stimulatory effect of 6-AH was specifically directed towards glu-plg or streptokinase, the ratios of the initial rate of plasmin generation in the presence of 6-AH over the controls were plotted against the inverse of the volume fraction of glu-plg or streptokinase after serial dilutions. The results indicated that the dilutions of glu-plg, but not of streptokinase, influenced the ratios, suggesting an interaction of 6-AH with glu-plg. Similar experiments were conducted to determine the mechanism of inhibition of streptokinase by fucoidan. The results indicated that fucoidan was interacting with streptokinase, but not with glu-plg. Circular dichroism studies of glu-plg in the near-ultraviolet spectra (250-308 nm) showed that addition of 6-AH enhanced the spectra in the region around certain chromophores, which reflected conformational changes. On the contrary, the far-ultraviolet spectra were almost identical. PMID:12032402

Harris, G; Doctor, V M

2002-06-01

218

Tissue-type plasminogen activator is an extracellular mediator of Purkinje cell damage and altered gait.  

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Purkinje neurons are a sensitive and specialised cell type important for fine motor movement and coordination. Purkinje cell damage manifests as motor incoordination and ataxia - a prominent feature of many human disorders including spinocerebellar ataxia and Huntington's disease. A correlation between Purkinje degeneration and excess cerebellar levels of tissue-type plasminogen activator (tPA) has been observed in multiple genetically-distinct models of ataxia. Here we show that Purkinje loss in a mouse model of Huntington's disease also correlates with a 200% increase in cerebellar tPA activity. That elevated tPA levels arise in a variety of ataxia models suggests that tPA is a common mediator of Purkinje damage. To address the specific contribution of tPA to cerebellar dysfunction we studied the T4 mice line that overexpresses murine tPA in postnatal neurons through the Thy1.2 gene promoter, which directs preferential expression to Purkinje cells within the cerebellum. Here we show that T4 mice develop signs of cerebellar damage within 10 weeks of birth including atrophy of Purkinje cell soma and dendrites, astrogliosis, reduced molecular layer volume and altered gait. In contrast, T4 mice displayed no evidence of microgliosis, nor any changes in interneuron density, nor alteration in the cerebellar granular neuron layer. Thus, excess tPA levels may be sufficient to cause targeted Purkinje cell degeneration and ataxia. We propose that elevated cerebellar tPA levels exert a common pathway of Purkinje cell damage. Therapeutically lowering cerebellar tPA levels may represent a novel means of preserving Purkinje cell integrity and motor coordination across a wide range of neurodegenerative diseases. PMID:23939410

Cops, Elisa J; Sashindranath, Maithili; Daglas, Maria; Short, Kieran M; da Fonseca Pereira, Candida; Pang, Terence Y; Lijnen, Roger H; Smyth, Ian M; Hannan, Anthony J; Samson, Andre L; Medcalf, Robert L

2013-11-01

219

Antibody-mediated targeting of the urokinase-type plasminogen activator proteolytic function neutralizes fibrinolysis in vivo  

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Urokinase-type plasminogen activator (uPA) plays a central role in tissue remodeling processes. Most of our understanding of the role of uPA in vivo is derived from studies using gene-targeted uPA-deficient mice. To enable in vivo studies on the specific interference with uPA functionality in mouse models, we have now developed murine monoclonal antibodies (mAbs) directed against murine uPA by immunization of uPA-deficient mice with the recombinant protein. Guided by enzyme-linked immunosorbent assay, Western blotting, surface plasmon resonance, and enzyme kinetic analyses, we have selected two highly potent and inhibitory anti-uPA mAbs (mU1 and mU3). Both mAbs recognize epitopes located on the B-chain of uPA that encompasses the catalytic site. In enzyme activity assays in vitro, mU1 blocked uPA-catalyzed plasminogen activation as well as plasmin-mediated pro-uPA activation, whereas mU3 only was directed against the first of these reactions. We additionally provide evidence that mU1, but not mU3, successfully targets uPA-dependent processes in vivo. Hence, systemic administration of mU1 (i) rescued mice treated with a uPA-activable anthrax protoxin and (ii) impaired uPA-mediated hepatic fibrinolysis in tissue-type plasminogen activator (tPA)-deficient mice, resulting in a phenotype mimicking that of uPA;tPA double deficient mice. Importantly, this is the first report demonstrating specific antagonist-directed targeting of mouse uPA at the enzyme activity level in a normal physiological process in vivo.

Lund, Ida K; Jögi, Annika

2008-01-01

220

Recombinant human erythropoietin reduces plasminogen activator inhibitor and ameliorates pro-inflammatory responses following trauma  

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Full Text Available "n  "n Background and the purpose of the study: Besides its hematopoietic effects, erythropoietin (EPO by mobilization of iron and modulation of some inflammatory cytokines has antioxidant and anti-inflammatory properties. The purpose of this study was to evaluate these effects of erythropoietin and its impact on organ function in traumatized patients. "n Methods: Twenty-six ICU-admitted traumatized patients within 24 hrs after trauma were randomly assigned to the EPO (received EPO, 300 units/Kg/day and Control (not received EPO groups. The inflammatory biomarkers including Tumor Necrosis Factor alpha (TNF-?, Interleukin 1 (IL-1, Plasminogen Activator Inhibitor 1 (PAI-1 and Nitrotyrosine were recorded at the admission, 3, 6 and 9 days thereafter. Acute Physiology and Chronic Health Evaluation (APACHE II and Sequential Organ Failure Assessment (SOFA scores were also recorded. "n Results: Among 12 patients (EPO group TNF-? level at the day of 9 (P=0.046, and within EPO group at the days of 3 (P=0.026 ameliorate, 6 (P=0.016, and 9 (P=0.052 were significantly lowered. Level of IL-1 and PAI-1 decreased significantly at days of 3, 6 and 9 post intervention. Also there were significant differences between two groups in the SOFA score during three measured time intervals (the first, third and seventh days. "n Conclusion: From the results of this study it seems that injection of erythrocyte stimulating agent is well tolerated and inhibits the inflammatory response and oxidative stress following trauma.

M Mojtahedzadeh

2011-05-01

 
 
 
 
221

Polymorphism in methylenetetrahydrofolate reductase, plasminogen activator inhibitor-1, and apolipoprotein E in hemodialysis patients  

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Full Text Available The methylenetetrahydrofolate reductase (MTHFR gene polymorphism, apolipoprotein E (apo s4 gene polymorphism and polymorphism of plasminogen activator inhibitor-1 (PAI-1 have been shown to be associated with end-stage renal disease (ESRD. To determine the prevalence of these mutations in Saudi patients with ESRD on hemodialysis, we studied the allelic frequency and genotype distribution in patients receiving hemodialysis and in a control group, all residing in the Eastern Province of Saudi Arabia. The genotypes were determined using allele specific hybridization procedures and were confirmed by restriction fragment length polymorphism. The T allele frequency and homozygous genotype of MTHFR in ESRD patients were 14% and 2.4%, respectively compared to 13.4% and 0%, respectively in the control group. The allele frequency and homozygous genotype of 4G/4G PAI-1 gene polymorphism were 46.4% and 4.8% respectively in ESRD patients compared to 57.1% and 32% respectively in the control group. The apo s4 allele frequency and homozygous genotype distribution in hemodialysis patients were 7% and 2.4%, respectively compared to 13% and 2% in the control group. Although allele frequency of C677T of MTHFR was statistically similar in the hemodialysis patients and in the control group, the homozygotes T allele genotype was over repre-sented in the hemodialysis group compared to normal. The prevalence of PAI-1 4G/4G polymorphism in ESRD patients was lower when com-pared to the control group. The prevalence of apo s4 allele did not differ significantly between the two groups. The present results demonstrate that all three studied polymorphic mutations are present in our population and that they may contribute to the etiology of the disease in our area.

Al-Muhanna Fahad

2008-01-01

222

Role of plasminogen activator inhibitor-1 in urokinase's paradoxical in vivo tumor suppressing or promoting effects.  

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Tumor proteases and inhibitors have been associated with paradoxical effects on tumor progression in preclinical and clinical settings. We previously reported that urokinase (uPA) overexpression delays tumor progression in mammary cancer. This study aimed to determine the role of plasminogen activator inhibitor-1 (PAI-1) on uPA's paradoxical in vivo effects. Using syngeneic murine models, we found that stable uPA overexpression promoted in vivo growth of colon tumors (MC-38) naturally expressing high PAI-1, whereas growth inhibition was observed in renal tumors (RENCA) expressing lower PAI-1 levels. In murine mammary carcinoma (4T1), uPA overexpression shifted the uPA/PAI-1 balance in favor of the protease, resulting in significantly reduced tumor growth and metastases in vivo. Conversely, increased tumor progression was observed in stable PAI-1 overexpressing 4T1 tumors as compared with uPA-overexpressing and control tumors. These effects were associated with downregulation of metastases promoting genes in uPA-overexpressing tumors, such as metalloproteinases, CXCL-1, c-Fos, integrin ?-5, VEGF-A, PDGF-?, and IL-1?. In PAI-1-overexpressing tumors, many of the above genes were upregulated. PAI-1 overexpressing tumors had increased total and new tumor microvessels, and increased tumor cell proliferation, whereas the opposite effects were found in uPA-overexpressing tumors. Finally, PAI-1 downregulation led to significant inhibition of 4T1 tumor growth and metastases in vivo. In conclusion, uPA's dual effects on tumor progression occur in the context of its interactions with endogenous PAI-1 expression. Our studies uncover novel mechanisms of in vivo tumor control by modulation of the balance between tumor proteases and inhibitors, which may be exploited therapeutically. PMID:22912336

Jing, Yuqi; Kovacs, Krisztina; Kurisetty, Vittal; Jiang, Zhijie; Tsinoremas, Nick; Merchan, Jaime R

2012-10-01

223

Validation of an immunoassay to measure plasminogen-activator inhibitor-1 concentrations in human saliva  

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Introduction: We have previously shown that the concentrations of D-dimer are significantly elevated in saliva compared with plasma. Saliva offers several advantages compared with blood analysis. We hypothesised that human saliva contains plasminogen activator inhibitor-1 (PAI-1) and that the concentrations are not affected by the time of saliva collection. The aim was to adopt and validate an immunoassay to quantify PAI-1 concentrations in saliva and to determine whether saliva collection time has an influence in the measurement. Materials and methods: Two saliva samples (morning and afternoon) from the same day were collected from healthy subjects (N = 40) who have had no underlying heart conditions. A customized AlphaLISA® immunoassay (PerkinElmer®, MA, USA) was adopted and used to quantify PAI-1 concentrations. We validated the analytical performance of the customized immunoassay by calculating recovery of known amount of analyte spiked in saliva. Results: The recovery (95.03%), intra- (8.59%) and inter-assay (7.52%) variations were within the acceptable ranges. The median salivary PAI-1 concentrations were 394 pg/mL (interquartile ranges (IQR) 243.4–833.1 pg/mL) in the morning and 376 (129.1–615.4) pg/mL in the afternoon and the plasma concentration was 59,000 (24,000–110,000) pg/mL. Salivary PAI-1 did not correlate with plasma (P = 0.812). Conclusions: The adopted immunoassay produced acceptable assay sensitivity and specificity. The data demonstrated that saliva contains PAI-1 and that its concentration is not affected by the time of saliva collection. There is no correlation between salivary and plasma PAI-1 concentrations. Further studies are required to demonstrate the utility of salivary PAI-1 in CVD risk factor studies. PMID:24969919

Zhang, Xi; Dimeski, Goce; Punyadeera, Chamindie

2014-01-01

224

The hepatic clearance of recombinant tissue-type plasminogen activator decreases after an inflammatory stimulus  

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Full Text Available We have shown that tissue-type plasminogen activator (tPA and plasma kallikrein share a common pathway for liver clearance and that the hepatic clearance rate of plasma kallikrein increases during the acute-phase (AP response. We now report the clearance of tPA from the circulation and by the isolated, exsanguinated and in situ perfused rat liver during the AP response (48-h ex-turpentine treatment. For the sake of comparison, the hepatic clearance of a tissue kallikrein and thrombin was also studied. We verified that, in vivo, the clearance of 125I-tPA from the circulation of turpentine-treated rats (2.2 ± 0.2 ml/min, N = 7 decreases significantly (P = 0.016 when compared to normal rats (3.2 ± 0.3 ml/min, N = 6. The AP response does not modify the tissue distribution of administered 125I-tPA and the liver accounts for most of the 125I-tPA (>80% cleared from the circulation. The clearance rate of tPA by the isolated and perfused liver of turpentine-treated rats (15.5 ± 1.3 µg/min, N = 4 was slower (P = 0.003 than the clearance rate by the liver of normal rats (22.5 ± 0.7 µg/min, N = 10. After the inflammatory stimulus and additional Kupffer cell ablation (GdCl3 treatment, tPA was cleared by the perfused liver at 16.2 ± 2.4 µg/min (N = 5, suggesting that Kupffer cells have a minor influence on the hepatic tPA clearance during the AP response. In contrast, hepatic clearance rates of thrombin and pancreatic kallikrein were not altered during the AP response. These results contribute to explaining why the thrombolytic efficacy of tPA does not correlate with the dose administered.

Nagaoka M.R.

2000-01-01

225

Technetium-99m modified recombinant tissue plasminogen activator to detect pulmonary embolism: a pilot study  

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Full text: Technetium 99m labelled modified recombinant tissue plasminogen activator (99mTc rt PA) has been shown to have a high sensitivity and specificity in the detection of venous thrombosis in the lower limbs in both symptomatic and asymptomatic patients. This study was performed to test the sensitivity of 99mTc rt PA scinitigraphy in the detection of pulmonary embolism (PE). Ten patients with a high clinical suspicion of PE and a very high probability lung scan (i.e. greater than three segmental areas of ventilation perfusion mismatch) were injected with 500 MBq of 99mTc rt PA with imaging of the legs and thorax taking place four hours post injection. Planar images of the legs were obtained, with both planar and SPECT images (using a double headed Picker Prism 2000) of the thorax being obtained. All images were viewed by nuclear medicine physicians. Of the ten patients with presumed PE, only two patients had abnormal SPECT Tc-99 rt-PA studies of the lungs. Only one of these patients had an abnormal planar image. In this group of patients, 99mTc rt PA has a sensitivity of 20 per cent in the detection of PE. Possible causes for this low sensitivity include the small size of the thrombi in lungs and the significant scatter into the lung caused by hepatic 99mTc rt-PA uptake. In the images of the legs, five patients had abnormal scans indicating the presence of DVT in 50 per cent of patients. This study has demonper cent of patients. This study has demonstrated that the sensitivity of 99mTc rt PA for the detection of PE is too low to be clinically useful In addition, the expected high prevalence of peripheral venous thrombosis in patients with PE has been confirmed

226

The miR-143/-145 cluster regulates plasminogen activator inhibitor-1 in bladder cancer  

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Background:Upregulation of the proto-oncogene plasminogen activator inhibitor-1 (PAI-1) is a common hallmark of various solid tumours, but the mechanisms controlling its expression are not fully understood.Methods:We investigate microRNAs (miRNAs) regulating PAI-1 in a panel of normal bladder urothelial biopsies, superficial Ta bladder tumours and invasive T1-T4 tumours using expression microarrays and qRT-PCR. The prognostic implications of PAI-1 deregulation are established by tissue microarray staining of non-muscle-invasive bladder tumours. MicroRNA repression of PAI-1 is assayed by ectopic miRNA expression, argonaute immunoprecipitation and luciferase assays.Results:We found that the miR-143/-145 cluster is downregulated in all stages of bladder cancer and inversely correlated with PAI-1 expression. Mature miR-143 and miR-145 are coordinately expressed, and both directly target the PAI-1 3'UTR, leading to reduced PAI-1 mRNA and protein levels. Furthermore, we show that PAI-1 and miR-145 levels may serve as useful prognostic markers for non-muscle-invasive bladder tumours for which accurate progressive outcome is currently difficult to predict.Conclusion:This report provides the first evidence for direct miRNA regulation of PAI-1 in bladder cancer. We also demonstrate mRNA co-targeting by a cluster of non-family miRNAs, and suggest miR-145 and PAI-1 as clinically relevant biomarkers in bladder cancer.British Journal of Cancer advance online publication, 22 November 2011; doi:10.1038/bjc.2011.520 www.bjcancer.com

Villadsen, S B; Bramsen, Jesper Bertram

2012-01-01

227

Histone deacetylase inhibitor impairs plasminogen activator inhibitor-1 expression via inhibiting TNF-?-activated MAPK/AP-1 signaling cascade.  

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Tumor necrosis factor-(TNF-)-? upregulates plasminogen activator inhibitor-(PAI-) 1 expression in pleural mesothelial cells (PMCs), contributing to fibrin deposition and pleural fibrosis. Histone deacetylases (HDACs) have been found implicated in fibrogenesis. However, the roles of TNF-? or HDAC in the regulation of PAI-1 expression have not been well investigated. We aimed to examine the effects and mechanisms of HDAC inhibition on TNF-?-induced PAI-1 expression in human PMCs. MeT-5A human PMCs were treated with TNF-? in the presence or absence of the m-carboxycinnamic acid bishydroxamide (CBHA), an HDAC class II inhibitor, and the HDAC activity, PAI-1 protein expression, mRNA, and activated signalings were analyzed. CBHA abrogated TNF-?-induced HDAC activity, PAI-1 protein and, mRNA expression in MeT-5A cells. Moreover, CBHA significantly enhanced mitogen-activated protein kinase phosphatase-(MKP-) 5/MKP-1 expression and inhibited p38/JNK activations, ATF2/c-Jun translocation, and PAI-1 promoter activity. Altogether, our data suggest that HDAC inhibition may abrogate TNF-?-activated MAPK/AP-1 signaling and PAI-1 expression in human PMCs. Given the antifibrotic effect through PAI-1 abrogation, CBHA may be utilized as a novel agent in the treatment of fibrotic diseases. PMID:24707477

Chen, Wei-Lin; Sheu, Joen-Rong; Hsiao, Che-Jen; Hsiao, Shih-Hsin; Chung, Chi-Li; Hsiao, George

2014-01-01

228

Discrimination of different forms of the murine urokinase plasminogen activator receptor on the cell surface using monoclonal antibodies  

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The urokinase plasminogen activator receptor (uPAR) is a versatile three-domain GPI-anchored protein, which binds urokinase plasminogen activator (uPA) and thereby focalises plasminogen activation on the cell surface. Generation of a proteolytic potential is essential in both normal physiological and pathological extracellular tissue remodelling processes. uPA can also cleave uPAR, resulting in liberation of the amino-terminal domain I, which encompasses binding sites for both uPA and the adhesion molecule, vitronectin. In order to localise the different uPAR forms on the plasma membrane of murine monocyte macrophage-like P388D.1 cells, we have now generated and characterised two high-affinity murine mAbs, mR3 and mR4, raised against murine uPAR. mR3 was found to recognise an epitope located in domain I of uPAR. Surface plasmon resonance analyses and cell binding studies revealed that this mAb was able to bind preformed complexes of murine pro-uPA and murine uPAR. In contrast, mR4 recognises domains II-III inuPAR and does not bind preformed pro-uPA-uPAR complexes in similar analyses. Immunofluorescence microscopy of P388D.1 cells revealed that mR3 stained the cells equally well in the presence or absence of saturation with the amino-terminal fragment of uPA, ATF. However, the signal intensity obtained using another uPAR domain I specific mAb, mR1, was significantly reduced upon ATF saturation. Furthermore, when adding ATF, mR4 selectively stained the cleaved receptor. Applying these newly generated mAbs, we additionally demonstrated that cleaved and intact uPAR was evenly distributed on the surface of these cells Udgivelsesdato: 2008/11/30

Rasch, M.G.; Pass, J.

2008-01-01

229

Method for the determination of fast acting plasminogen activator inhibitor capacity (PAI-cap) in plasma, platelets and endothelial cells.  

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A titration assay for the determination of the fast acting plasminogen activator inhibitor capacity (PAI-cap) was developed. Most of the hitherto published assays for fast acting PAI are reported to have the disadvantage of non-parallel titration curves of tissue plasminogen activator (t-PA) in buffer and plasma. In the assay reported here, this problem has been overcome by adequate predilution of the samples, thus achieving parallel titration curves regardless of the individual PAI-cap of a sample. Provided that values are calculated from parallel titration curves, reproducible PAI-cap values at different dilutions of a sample are obtained. This assay can be applied for the determination of PAI-cap in plasma, serum and other biological fluids as platelet releasates and endothelial cell conditioned medium. PAI-cap of plasma of 10 healthy male volunteers ranged from 15.3 to 32.3 arbitrary inhibitor units AU/ml (24.5 +/- 5.2, mean +/- SD). The alternative use of three different anticoagulants (citrate, EDTA, heparin) had no influence on PAI-cap determinations. Serum generated from blood contained a mean of PAI-cap of 129% in comparison to the plasma of the same donor indicating the release of PAI from cells during clotting. Plasma PAI-cap changed during the day with a constant decrease from the highest levels in the morning (100%) to low levels in the evening (62.9%). Platelets aggregated by thrombin released plasminogen activator inhibitor amounting to a mean PAI-cap of 4.33 +/- 2.98 AU per 2.5 X 10(8) cells. PMID:3798411

Speiser, W; Bowry, S; Anders, E; Binder, B R; Müller-Berghaus, G

1986-11-15

230

Synergistic and multidimensional regulation of plasminogen activator inhibitor type 1 expression by transforming growth factor type ? and epidermal growth factor  

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The major physiological inhibitor of plasminogen activator, type I plasminogen activator inhibitor (PAI-1), controls blood clotting and tissue remodeling events that involve cell migration. Transforming growth factor type ? (TGF?) and epidermal growth factor (EGF) interact synergistically to increase PAI-1 mRNA and protein levels in human HepG2 and mink Mv1Lu cells. Other growth factors that activate tyrosine kinase receptors can substitute for EGF. EGF and TGF? regulate PAI-1 by synergistically activating transcription, which is further amplified by a decrease in the rate of mRNA degradation, the latter being regulated only by EGF. The combined effect of transcriptional activation and mRNA stabilization results in a rapid 2-order of magnitude increase in the level of PAI-1. TGF? also increases the sensitivity of the cells to EGF, thereby recruiting the cooperation of EGF at lower than normally effective concentrations. The contribution of EGF to the regulation of PAI-1 involves the MAPK pathway, and the synergistic interface with the TGF? pathway is downstream of MEK1/2 and involves phosphorylation of neither ERK1/2 nor Smad2/3. Synergism requires the presence of both Smad and AP-1 recognition sites in the promoter. This work demonstrates the existence of a multidimensional cellular mechanism by which EGF and TGF? are able to promote large and rapid changes in PAI-1 expression.

Song, Xiaoling; Thalacker, F.W.; Nilsen-Hamilton, Marit

2012-04-06

231

Involvement of tissue plasminogen activator "tPA" in ethanol-induced locomotor sensitization and conditioned-place preference.  

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Ethanol is one of the most abused drugs in the western societies. It is well established that mesolimbic dopaminergic neurons mediate the rewarding properties of ethanol. In our previous studies we have shown that the serine protease tissue plasminogen activator (tPA) is involved in the rewarding properties of morphine and amphetamine. In the current study, we investigated the role of tPA in ethanol-induced behavioral sensitization and conditioned-place preference (CPP). Ethanol treatment dose-dependently induced tPA enzymatic activity in the nucleus accumbens (NAc). In addition, ethanol-induced increase in tPA activity was completely inhibited by pre-treatment with the dopamine D1 and D2 receptor antagonists SCH23390 and raclopride respectively. Furthermore, ethanol-induced locomotor stimulation, behavioral sensitization and conditioned-place preference were enhanced following tPA over-expression in the NAc using a lentiviral vector. In contrast, tPA knock down in the NAc with specific shRNA blocked the rewarding properties of ethanol. The defect of locomotor stimulation in shRNA-injected mice was reversed by microinjections of exogenous recombinant tPA into the nucleus accumbens. Collectively, these results indicate, for the first time, that activation of tPA is effective in enhancing the rewarding effects of ethanol. Targeting the tissue plasminogen activator system would provide new therapeutic approaches to the treatment of alcoholism. PMID:21945298

Bahi, Amine; Dreyer, Jean-Luc

2012-01-01

232

A cyclic peptidylic inhibitor of murine urokinase-type plasminogen activator: Changing species specificity by substitution of a single residue  

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Abstract Urokinase-type plasminogen activator (uPA) is a potential therapeutic target in a variety of pathological conditions, including cancer. In order to find new principles for inhibiting uPA in murine cancer models, we screened a phage-displayed peptide library with murine uPA as bait. We thereby isolated several murine uPA-binding peptide sequences, the most predominant of which was the disulphide-bridged constrained sequence CPAYSRYLDC, which we will refer to as mupain-1. A ...

2008-01-01

233

Selective suicide gene therapy of colon cancer exploiting the urokinase plasminogen activator receptor promoter.  

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Colon cancer is the third and fourth most prevalent cancer among Iranian men and women, respectively. Suicide gene therapy is one of the alternative therapeutic modalities for cancer. The application of specific promoters for therapeutic genes should decrease the adverse effects of this modality. The combined aims of this study were to design a specific suicide gene therapy construct for colon cancer and study its effect in distinct representatives of transformed and nontransformed cells. The KRAS oncogene signaling pathway is one of the most important signaling pathways activated in colon cancer; therefore, we inserted the urokinase plasminogen activator receptor (uPAR; PLAUR gene) promoter as one of the upregulated promoters by this pathway upstream of a suicide gene (thymidine kinase [TK]) and a reporter gene (beta-galactosidase, beta-gal [LacZ]). This promoter is a natural combination of different motifs responsive to the RAS signaling pathway, such as the transcription factors AP1 (FOS/JUN), SP1, SP3, and AP2alpha, and nuclear factor kappa B (NFkappaB). The reporter plasmid under the control of the uPAR promoter (PUCUPARLacZ) had the ability to express beta-gal in colon cancer cells (human colon adenocarcinoma [SW480] and human colorectal carcinoma [HCT116] cell lines), while it could not express beta-gal in nontransformed human umbilical vein endothelial cells (HUVEC) and normal colon cells. After confirming the ability of pUCUPARTK (suicide plasmid) to express TK in SW480 and HCT116 cells by real-time PCR, cytotoxicity assays showed that pUCUPARTK decreased the viability of these cells in the presence of ganciclovir 20 and 40 microg/mL (and higher), respectively. Although M30 CytoDEATH antibody could not detect a significant rate of apoptosis induced by ganciclovir in pUCUPARTK-transfected HCT116 cells, the percentage of stained cells was marked in comparison with untreated cells. While this antibody could detect apoptosis in HCT116 cell line transfected with positive control plasmid, it could not detect apoptosis in SW480 cells transfected with the same positive control. This discrepancy could be attributed to the different mechanisms of TK/ganciclovir-induced apoptosis in tumor protein p53 (TP53)-expressing (HCT116) and -deficient (SW480) cells. Annexin-propidium iodide staining could detect apoptosis in treated, pUCUPARTK-transfected SW480 and HCT116 cells. This study showed that the uPAR promoter can be considered as a suitable candidate for specific suicide gene therapy of colon cancer and probably other cancers in which the RAS signaling pathway is involved in their carcinogenesis process. PMID:20199127

Teimoori-Toolabi, Ladan; Azadmanesh, Kayhan; Amanzadeh, Amir; Zeinali, Sirous

2010-04-01

234

Plasminogen activation independent of uPA and tPA maintains wound healing in gene-deficient mice  

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Simultaneous ablation of the two known activators of plasminogen (Plg), urokinase-type (uPA) and the tissue-type (tPA), results in a substantial delay in skin wound healing. However, wound closure and epidermal re-epithelialization are significantly less impaired in uPA;tPA double-deficient mice than in Plg-deficient mice. Skin wounds in uPA;tPA-deficient mice treated with the broad-spectrum matrix metalloproteinase (MMP) inhibitor galardin (N-[(2R)-2-(hydroxamido-carbonylmethyl)-4-methylpentanoyl]-L-tryptophan methylamide) eventually heal, whereas skin wounds in galardin-treated Plg-deficient mice do not heal. Furthermore, plasmin is biochemically detectable in wound extracts from uPA;tPA double-deficient mice. In vivo administration of a plasma kallikrein (pKal)-selective form of the serine protease inhibitor ecotin exacerbates the healing impairment of uPA;tPA double-deficient wounds to a degree indistinguishable from that observed in Plg-deficient mice, and completely blocks the activity of pKal, but not uPA and tPA in wound extracts. These findings demonstrate that an additional plasminogen activator provides sufficient plasmin activity to sustain the healing process albeit at decreased speed in the absence of uPA, tPA and galardin-sensitive MMPs and suggest that pKal plays a role in plasmin generation.

Lund, Leif R; Green, Kirsty A

2006-01-01

235

WRN polymorphisms affect expression levels of plasminogen activator inhibitor type 1 in cultured fibroblasts  

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Full Text Available Abstract Background Recessive mutations in WRN gene eliminate WRN protein function (helicase and cause Werner syndrome. One of the most important clinical features of Werner syndrome patients are the premature onset and accelerated atherosclerosis process. Studies carried out on polymorphic WRN locus have shown that the alleles 1367R and 1074L confer protection for cardiovascular disease. Given that the levels of plasminogen activator inhibitor type 1 (PAI-1 were found to be significantly increased in Werner syndrome patients, is quiet possible that PAI-1 expression could be under regulation of WRN helicase. Therefore the purpose of this work was to evaluate the role of WRN polymorphism in modulating the expression of PAI-1. Methods In order to accomplish our aim, an array of primary cultured fibroblasts from normal adult donors was genotyped for polymorphisms of both the WRN and PAI-1 loci. In addition, steady state levels of WRN and PAI-1 were measured by semi-quantitative RT-PCR assays in such cultures. To search for the potential relationship between the lack of WRN protein and PAI-1 expression, heterozygous cultures of fibroblasts (1367RC/1074LF; WRN genotype were treated with a molecule of interference RNA against WRN messenger RNA (mRNA. Results We found that, carriers of 1367R and 1074L alleles of WRN shown to have low amounts of PAI-1 in plasma (7.56 ± 5.02, as compared with carriers of 1367C and 1074F alleles (16.09 ± 6.03. Moreover, fibroblasts from carriers with these alleles had low expression levels of PAI-1 mRNA. The treatment of heterozygous primary fibroblast cultures (1367RC/1074LF; WRN genotype with iRNA against WRN mRNA caused PAI-1 overexpression. Treatment with normal PAI-1 inducers (TGF?, TNF?, or insulin in these cultures and from those with genotypes 1367CC/1074FF and 1367RR/1074FL resulted in a genotype-dependent PAI-1 expression level. Conclusion Our results suggest that polymorphisms in the WRN gene might have a significant role regulating PAI-1 levels in healthy individuals and "normal states" as well as acute or chronic stress, obesity, aging, acute inflammation, among others, where characteristic high levels of insulin, TNF ? and TGF?, could favor PAI-1 high levels in carriers with polymorphic variants (C and F alleles, beyond the levels reached by carriers with other alleles (R and L alleles.

Oviedo-Rodríguez Vladimir

2008-02-01

236

The hepatic clearance of recombinant tissue-type plasminogen activator decreases after an inflammatory stimulus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english We have shown that tissue-type plasminogen activator (tPA) and plasma kallikrein share a common pathway for liver clearance and that the hepatic clearance rate of plasma kallikrein increases during the acute-phase (AP) response. We now report the clearance of tPA from the circulation and by the isol [...] ated, exsanguinated and in situ perfused rat liver during the AP response (48-h ex-turpentine treatment). For the sake of comparison, the hepatic clearance of a tissue kallikrein and thrombin was also studied. We verified that, in vivo, the clearance of 125I-tPA from the circulation of turpentine-treated rats (2.2 ± 0.2 ml/min, N = 7) decreases significantly (P = 0.016) when compared to normal rats (3.2 ± 0.3 ml/min, N = 6). The AP response does not modify the tissue distribution of administered 125I-tPA and the liver accounts for most of the 125I-tPA (>80%) cleared from the circulation. The clearance rate of tPA by the isolated and perfused liver of turpentine-treated rats (15.5 ± 1.3 µg/min, N = 4) was slower (P = 0.003) than the clearance rate by the liver of normal rats (22.5 ± 0.7 µg/min, N = 10). After the inflammatory stimulus and additional Kupffer cell ablation (GdCl3 treatment), tPA was cleared by the perfused liver at 16.2 ± 2.4 µg/min (N = 5), suggesting that Kupffer cells have a minor influence on the hepatic tPA clearance during the AP response. In contrast, hepatic clearance rates of thrombin and pancreatic kallikrein were not altered during the AP response. These results contribute to explaining why the thrombolytic efficacy of tPA does not correlate with the dose administered.

M.R., Nagaoka; M., Kouyoumdjian; D.R., Borges.

237

Characterisation of urokinase plasminogen activator receptor variants in human airway and peripheral cells  

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Full Text Available Abstract Background Expression of the urokinase plasminogen activator receptor (UPAR has been shown to have clinical relevance in various cancers. We have recently identified UPAR as an asthma susceptibility gene and there is evidence to suggest that uPAR may be upregulated in lung diseases such as COPD and asthma. uPAR is a key receptor involved in the formation of the serine protease plasmin by interacting with uPA and has been implicated in many physiological processes including proliferation and migration. The current aim was to determine key regulatory regions and splice variants of UPAR and quantify its expression in primary human tissues and cells (including lung, bronchial epithelium (HBEC, airway smooth muscle (HASM and peripheral cells. Results Using Rapid Amplification of cDNA Ends (RACE a conserved transcription start site (-42 to -77 relative to ATG was identified and multiple transcription factor binding sites predicted. Seven major splice variants were identified (>5% total expression, including multiple exon deletions and an alternative exon 7b (encoding a truncated, soluble, 229aa protein. Variants were differentially expressed, with a high proportion of E7b usage in lung tissue and structural cells (55–87% of transcripts, whereas classical exon 7 (encoding the GPI-linked protein was preferentially expressed in peripheral cells (~80% of transcripts, often with exon 6 or 5+6 deletions. Real-time PCR confirmed expression of uPAR mRNA in lung, as well as airway and peripheral cell types with ~50–100 fold greater expression in peripheral cells versus airway cells and confirmed RACE data. Protein analysis confirmed expression of multiple different forms of uPAR in the same cells as well as expression of soluble uPAR in cell supernatants. The pattern of expression did not directly reflect that seen at the mRNA level, indicating that post-translational mechanisms of regulation may also play an important role. Conclusion We have identified multiple uPAR isoforms in the lung and immune cells and shown that expression is cell specific. These data provide a novel mechanism for uPAR regulation, as different exon splicing may determine uPAR function e.g. alternative E7b results in a soluble isoform due to the loss of the GPI anchor and exon deletions may affect uPA (ligand and/or integrin binding and therefore influence downstream pathways. Expression of different isoforms within the lung should be taken into consideration in studies of uPAR in respiratory disease.

Sayers Ian

2009-07-01

238

The hepatic clearance of recombinant tissue-type plasminogen activator decreases after an inflammatory stimulus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english We have shown that tissue-type plasminogen activator (tPA) and plasma kallikrein share a common pathway for liver clearance and that the hepatic clearance rate of plasma kallikrein increases during the acute-phase (AP) response. We now report the clearance of tPA from the circulation and by the isol [...] ated, exsanguinated and in situ perfused rat liver during the AP response (48-h ex-turpentine treatment). For the sake of comparison, the hepatic clearance of a tissue kallikrein and thrombin was also studied. We verified that, in vivo, the clearance of 125I-tPA from the circulation of turpentine-treated rats (2.2 ± 0.2 ml/min, N = 7) decreases significantly (P = 0.016) when compared to normal rats (3.2 ± 0.3 ml/min, N = 6). The AP response does not modify the tissue distribution of administered 125I-tPA and the liver accounts for most of the 125I-tPA (>80%) cleared from the circulation. The clearance rate of tPA by the isolated and perfused liver of turpentine-treated rats (15.5 ± 1.3 µg/min, N = 4) was slower (P = 0.003) than the clearance rate by the liver of normal rats (22.5 ± 0.7 µg/min, N = 10). After the inflammatory stimulus and additional Kupffer cell ablation (GdCl3 treatment), tPA was cleared by the perfused liver at 16.2 ± 2.4 µg/min (N = 5), suggesting that Kupffer cells have a minor influence on the hepatic tPA clearance during the AP response. In contrast, hepatic clearance rates of thrombin and pancreatic kallikrein were not altered during the AP response. These results contribute to explaining why the thrombolytic efficacy of tPA does not correlate with the dose administered.

M.R., Nagaoka; M., Kouyoumdjian; D.R., Borges.

2000-01-01

239

siRNA against plasminogen activator inhibitor-1 ameliorates bleomycin-induced lung fibrosis in rats  

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Aim: Plasminogen activator inhibitor-1 (PAI-1) is involved in the progression of pulmonary fibrosis. The present study was undertaken to examine the effects on pulmonary fibrosis of silencing PAI-1 expression with small interfering RNA (siRNA) and to assess the possible underlying mechanisms. Methods: Male Wistar rats were subjected to intratracheal injection of bleomycin (BLM, 5 mg/kg, 0.2 mL) to induce pulmonary fibrosis. Histopathological changes of lung tissue were examined with HE or Masson's trichrome staining. The expression levels of ?-smooth muscle actin (?-SMA), collagen type-I and type-III, caspase-3, as well as p-ERK1/2 and PI3K/Akt in the lung tissue were evaluated using imunohistochemistry and Western blot analyses. The fibroblasts isolated from BLM-induced fibrotic lung tissue were cultured and transfected with pcDNA-PAI-1 or PAI-1siRNA. The expression level of PAI-1 in the fibroblasts was measured using real time RT-PCR and Western blot analysis. The fibroblast proliferation was evaluated using MTT assay. Results: Intratracheal injection of PAI-1-siRNA (7.5 nmoL/0.2 mL) significantly alleviated alveolitis and collagen deposition, reduced the expression of PAI-1, ?-SMA, collagen type-I and collagen type-III, and increased the expression of caspase-3 in BLM-induced fibrotic lung tissue. In consistence with the in vivo results, the proliferation of the cultured fibroblasts from BLM-induced fibrotic lung tissue was inhibited by transfection with PAI-1-siRNA, and accelerated by overexpression of PAI-1 by transfection with pcDNA-PAI-1. The expression of caspase-3 was increased as a result of PAI-1 siRNA transfection, and decreased after transfection with pcDNA-PAI-1. In addition, the levels of p-ERK1/2 and PI3K/Akt in the fibrogenic lung tissue were reduced after treatment with PAI-1siRNA. Conclusion: The data demonstrate that PAI-1 siRNA inhibits alveolitis and pulmonary fibrosis in BLM-treated rats via inhibiting the proliferation and promoting the apoptosis of fibroblasts. Suppression ERK and AKT signalling pathways might have at least partly contributed to this process. Targeting PAI-1 is a promising therapeutic strategy for pulmonary fibrosis. PMID:22659625

Zhang, Yan-ping; Li, Wen-bin; Wang, Wei-li; Liu, Jian; Song, Shu-xia; Bai, Lin-lin; Hu, Yu-yan; Yuan, Ya-dong; Zhang, Min

2012-01-01

240

Plasminogen activator inhibitor-1 removal using dextran sulphate columns. Evidence of PAI-1 homeostasis.  

LENUS (Irish Health Repository)

Patients with high plasma plasminogen activator inhibitor-1 (PAI-1) antigen levels are prone to develop thrombosis. Lowering PAI-1 levels may offer a therapeutic option and help to better understand PAI-1 metabolism. We examined the effect on plasma PAI-1 levels of LDL-apheresis using dextran sulphate (DS) columns in 12 patients (9 male, 3 female, 49 +\\/- 10 years) with heterozygous familial hypercholesterolaemia and coronary artery disease. One plasma volume equivalent (2.3-4.0 l) was treated during each procedure (at flow rates of 23 +\\/- 2 ml\\/min). Lipids and PAI-1 antigen levels were measured in plasma before and immediately after 19 aphereses (once in 7 patients, twice in 3 patients and three times in 2 patients) and also at 3 and 7 days post apheresis in five of these patients and in the column eluates from 8 of these patients. DS-apheresis reduced plasma cholesterol (50 +\\/- 8%), triglyceride (45 +\\/- 27%), apolipoprotein B (59 +\\/- 10%) and PAI-1 antigen levels from 10.2 +\\/- 5.2 to 6.0 +\\/- 3.1 ng\\/ml (P = 0.005). The PAI-I changes were independent of circadian variation. PAI-I bound to the DS-columns (3.51 +\\/- 1.03 ng\\/ml filtered plasma) and the percent of filtered PAI-1 that was bound correlated inversely (r = -0.81, P < 0.02) with basal PAI-1 levels indicating a high affinity saturable binding process. In four patients, plasma PAI-1 levels post-apheresis were higher than expected based on the amount of PAI-removed by the DS columns. The difference between the expected and actual PAI-1 level post apheresis, reflecting PAI-1 secretion or extracellular redistribution, correlated inversely with basal PAI-1 levels (r = -0.83, P = 0.01). PAI-1 levels returned to baseline pre-apheresis values 7 days post apheresis. PAI-1 antigen may be removed from plasma without adverse effect, resulting temporarily in its extracellular redistribution and restoration to baseline levels over one week. PAI-1 redistribution particularly when baseline pre-apheresis values were low may reflect a homeostatic mechanism to maintain sufficient PAI-1 levels. Procedures that could selectively remove PAI-1 from plasma may offer a treatment option for those with very high plasma PAI-1 levels and thrombosis.

Maher, Vincent M G

2009-08-01

 
 
 
 
241

Metastatic behavior of human melanoma cell lines in nude mice correlates with urokinase-type plasminogen activator, its type-1 inhibitor, and urokinase-mediated matrix degradation  

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Five out of six human melanoma cell lines tested were able to degrade in vitro a smooth muscle cell extracellular matrix in a plasmin- dependent way. In three of these five cell lines, this process was mediated by tissue-type plasminogen activator (t-PA) and in the other two cell lines by urokinase-type plasminogen activator (u-PA). All melanoma cell lines produced t-PA mRNA and protein, whereas only the two cell lines showing u-PA-mediated matrix degradation produced u-PA mRNA and protein. T...

1991-01-01

242

Urokinase-type plasminogen activator receptor (uPAR) as a promising new imaging target : potential clinical applications  

DEFF Research Database (Denmark)

Urokinase-type plasminogen activator receptor (uPAR) has been shown to be of special importance during cancer invasion and metastasis. However, currently, tissue samples are needed for measurement of uPAR expression limiting the potential as a clinical routine. Therefore, non-invasive methods are needed. In line with this, uPAR has recently been identified as a very promising imaging target candidate. uPAR consists of three domains attached to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor and binds it natural ligand uPA with high affinity to localize plasminogen activation at the cell surface. Due to the importance of uPAR in cancer invasion and metastasis, a number of high-affinity ligands have been identified during the last decades. These ligands have recently been used as starting point for the development of a number of ligands for imaging of uPAR using various imaging modalities such as optical imaging, magnetic resonance imaging, single photon emission computer tomography (SPECT) and positron emission topography (PET). In this review, we will discuss recent advances in the development of uPAR-targeted imaging ligands according to imaging modality. In addition, we will discuss the potential future clinical application for uPAR imaging as a new imaging biomarker.

Persson, Morten; Kjaer, Andreas

2013-01-01

243

Fibrin membrane pupillary-block glaucoma after uneventful cataract surgery treated with intracameral tissue plasminogen activator: a case report  

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Full Text Available Abstract Background Fibrin pupillary-block glaucoma is a rare complication after cataract surgery. The treatment for this condition is still controversial, since Nd:YAG laser fibrin membranotomy tends to reocclude and laser peripheral iridotomy entails the risk of damaging the corneal endothelium in the presence of corneal edema associated with elevated intraocular pressure. Case presentation A 62-year-old man with diabetes mellitus developed acute elevation of intraocular pressure with a shallow anterior chamber five days after uneventful cataract surgery. Initially, slit lamp examination provided only limited information due to severe corneal edema. After resolution of corneal edema with systemic glaucoma therapy, a complete fibrin membrane was observed across the pupil by slit lamp examination. Anterior segment optic coherence tomography clearly revealed a thin fibrin membrane covering the entire pupillary space, a shallow anterior chamber, and a deep posterior chamber. The intraocular lens was not observed by anterior segment optic coherence tomography. In contrast, ultrasound biomicroscopy, which has superior penetration depth, was able to visualize the intraocular lens deep in the posterior chamber. Injection of tissue plasminogen activator into the anterior chamber resulted in complete fibrinolysis and released the pupillary block. Conclusion This case suggests that ocular anterior segment imaging modalities, especially ultrasound biomicroscopy, serve as powerful diagnostic tools to identify mechanisms of acute angle closure glaucoma, which is often accompanied by poor intraocular visibility. This is the first reported case of fibrin pupillary-block glaucoma after cataract surgery successfully treated with intracameral tissue plasminogen activator.

Yoshino Hideaki

2012-03-01

244

Successful thrombolysis of a thrombosed prosthetic mitral valve using a synthetic tissue plasminogen activator: a case report  

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Full Text Available Abstract Introduction Prosthetic valve thrombosis is a rare but life-threatening condition that requires careful evaluation and prompt treatment. While surgical intervention remains the gold standard, thrombolytic therapy is now emerging as a potential substitute. Various thrombolytic treatments including streptokinase, urokinase and recombinant tissue plasminogen activators have been reported with variable success rates. However, the data on the use of tenecteplase (a synthetic tissue plasminogen activator is limited. Case presentation A 44-year-old Middle Eastern man with a previously implanted prosthetic mitral valve presented with exertional dyspnea and orthopnea. Investigations revealed a thrombosed prosthetic mitral valve. Successful thrombolysis was achieved using tenecteplase which lead to the complete restoration of valve function with no risk to the patient. Conclusion Prosthetic valve thrombosis is a rare but life threatening condition, the diagnosis of which requires a high index of suspicion. Tenecteplase can be used successfully in the management of such cases. It has proved to be useful with no extra risk to the patient.

Al-Fadhli Jamal

2010-08-01

245

Differential regulation of protease activated receptor-1 and tissue plasminogen activator expression by shear stress in vascular smooth muscle cells  

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Recent studies have demonstrated that vascular smooth muscle cells are responsive to changes in their local hemodynamic environment. The effects of shear stress on the expression of human protease activated receptor-1 (PAR-1) and tissue plasminogen activator (tPA) mRNA and protein were investigated in human aortic smooth muscle cells (HASMCs). Under conditions of low shear stress (5 dyn/cm2), PAR-1 mRNA expression was increased transiently at 2 hours compared with stationary control values, whereas at high shear stress (25 dyn/cm2), mRNA expression was decreased (to 29% of stationary control; Pcells, indicating that the effects of shear stress on human PAR-1 were not species-specific. Flow cytometry and ELISA techniques using rat smooth muscle cells and HASMCs, respectively, provided evidence that shear stress exerted similar effects on cell surface-associated PAR-1 and tPA protein released into the conditioned media. The decrease in PAR-1 mRNA and protein had functional consequences for HASMCs, such as inhibition of [Ca2+] mobilization in response to thrombin stimulation. These data indicate that human PAR-1 and tPA gene expression are regulated differentially by shear stress, in a pattern consistent with their putative roles in several arterial vascular pathologies.

Papadaki, M.; Ruef, J.; Nguyen, K. T.; Li, F.; Patterson, C.; Eskin, S. G.; McIntire, L. V.; Runge, M. S.

1998-01-01

246

Mechanism of the synergistic effect between oversulfated chondroitin-6-sulfate and lysine or 6-aminohexanoic acid in enhancing the in-vitro activation of glutamic plasminogen by tissue plasminogen activator or urokinase.  

Science.gov (United States)

Earlier studies of addition of naturally sulfated polysaccharides including unfractionated heparin showed a significant enhancement of the in-vitro activation of glutamic plasminogen (Glu-Plg) by tissue plasminogen activator (t-PA) or urokinase plasminogen activator (u-PA). However, supplementing of physiological concentration of NaCl (0.9%) to the buffer reversed the enhancement. To overcome this reversal attempts were made to oversulfate the compounds and re-evaluate their biological properties. Chondroitin-6-sulfate (N-2) was oversulfated using chlorosulfonic acid-pyridine complex and isolated as the sodium salt. Infrared and H-NMR studies of the oversulfated compound showed introduction of new sulfate groups with the formation of 60% of chondroitin-4-6-disulfate. In-vitro studies were conducted on comparing the effect of oversulfated chondroitin-6-sulfate (S-2) with native compound (N-2) and unfractionated heparin in enhancing the activation of Glu-Plg by t-PA or u-PA using 0.05 mol/l Tris buffer (pH 7.3) containing 0.9% of NaCl. The enhancement of activation of Glu-Plg by t-PA or u-PA was measured by formation of plasmin using H-D-Glu-Phe-Lys-pNA (S-2403) as the substrate. The activation by t-PA was enhanced two-fold by 2.86 microg/ml of S-2, 4-6-fold by addition of 32.4 mmol/l of lysine or 5.4 mmol/l of 6-aminohexanoic acid (6-AH) and 14-16-fold enhancement by addition of both S-2 and lysine or S-2 and 6-AH showing a synergistic effect, whereas unfractionated heparin alone gave no enhancement and in conjunction with lysine or 6-AH gave no additional enhancement. Similar studies using u-PA in place of t-PA gave identical results. During the activation of Glu-Plg to plasmin, lysine plasminogen (Lys-Plg) is reported to be an intermediate. Therefore we investigated the role of S-2, lysine and 6-AH in the activation of Lys-Plg to plasmin. The results showed that S-2 enhanced this activation, whereas lysine or 6-AH which were active in enhancing the activation of Glu-Plg were not active using Lys-Plg indicating that the site of enhancement by lysine or 6-AH was during the initial phase. Double reciprocal plot of Glu-Plg activation by t-PA with or without S-2 and lysine showed no change in Km but a 10-fold increase of Kcat suggesting a template mechanism for the attenuation when both cofactors are used. PMID:20445443

Kouemo, Stella; McMillan, Erinn; Doctor, Vasant

2010-07-01

247

Studying the Activity of Fibroblast Growth Factor 18 and Urokinase Plasminogen Activator Receptor Promoters in Two Colon Cancer Cell Lines  

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Full Text Available Introduction: Wnt and k-ras are two main signaling pathways activated in colon cancer.Many genes are upregulated downstream of these signaling pathways. The aim of this studywas to assess the activity of Wnt and k-ras in HCT116 and SW480 cell lines by makingtwo reporter constructs using promoters downstream of these pathways (fibroblast growthfactor18 [FGF18] and urokinase plasminogen activator receptor [UPAR].Materials and Methods: UPARLacZ, FGF18LacZ, negative (pUCLacZ and positive (CMVLacZcontrol plasmids and pRc/CMV2CAT were constructed. Expressions of LacZ in bothcell lines were studied by ?gal staining and ELISA after normalization with CAT expression.Results: In both cell lines, FGF18LacZ transfected cells stained more than UPARLacZ transfectedones. This difference was more prominent in SW480. Both constructs have the abilityof expression in both cell lines. It was also proven that FGF18LacZ was significantly moreactive than UPARLacZ in both cell lines. Expression of FGF18LacZ in HCT116 and SW480cell lines was respectively 1.34 and 4.4 times more than UPARLacZ.Conclusion: Despite the fact that in HCT116 the Ras pathway is activated, FGF18LacZ ismore active than UPARLacZ although the UPAR promoter is more active in HCT116 cell linethan SW480 cell line. These findings are in accordance with previous studies that in all coloncancer cell lines Wnt signaling pathway is active even though there is no mutation in anypart of it. Wnt is the main signaling pathway responsible for carcinogenesis in colon epithelialcells. These constructs can be used as reporters for studying the above mentioned signalingpathways in other cell lines.

Ladan Teimoori-Toolabi

2009-01-01

248

Cytokeratin 8 ectoplasmic domain binds urokinase-type plasminogen activator to breast tumor cells and modulates their adhesion, growth and invasiveness  

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Full Text Available Abstract Background Generation of plasmin is a characteristic of tumor cells, promoting the degradation of extracellular matrix, tumor progression and metastasis. The process is accelerated if plasminogen and plasminogen activator are bound to their cell surface receptors. Results In this study we show that the monoclonal antibody that recognizes an epitope on the cytokeratin 8 (CK8 ectoplasmic domain (anti-CK MAb inhibits plasminogen activation mediated by urokinase-type plasminogen activator (uPA in MCF-7 and MCF-10A neoT cells. The ectoplasmic domain of CK8 acts as a binding site for plasminogen, however, by using confocal microscopy, we demonstrated that it is also co-localized with uPA. CK8, therefore, function also as a receptor for uPA on the cell surface, and the presence of anti-CK MAb may prevent the binding of uPA to a designated CK8 motif. The consequent inhibition of plasmin generation resulted in changed cell morphology, enhanced cell adhesion to fibronectin, reduced invasion potential, and an enhanced G1/S transition. Moreover, surface plasmon resonance analysis showed that the synthetic dodecapeptide corresponding to the epitope sequence (VKIALEVEIATY, binds uPA in the nanomolar range. Conclusion These novel findings suggest a model in which CK8, together with uPA, plasminogen and fibronectin, constitutes a signaling platform capable of modulating cell adhesion/growth-dependent signal transduction in breast tumor cells. Anti-CK MAb, which competes for the binding site for uPA, could be used as an agent to reduce the invasive potential of breast tumor cells.

Doljak Bojan

2009-10-01

249

Accelerated thrombus lysis in the blood of plasminogen activator inhibitor deficient mice is inhibited by PAI-1 with a very long half-life.  

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Patients with defective plasminogen activator inhibitor protein (PAI-1) or with PAI-1 deficiency can experience hemorrhage as a result of a hyperfibrinolysis. In these patients, a normal thrombus forms, but endogenous lysis is unchecked as tissue plasminogen activator is unopposed. Treatment includes anti-fibrinolytic agents, including oral tranexamic acid. Another treatment option is the administration of PAI-1, but this serpin rapidly inactivates itself. We have developed a mutant plasminogen activator inhibitor with a very long half life (VLHL PAI-1, t1/2>700 h). Here we investigate VLHL PAI-1 effects in the blood of PAI-1 deficient mice, as a model of human disease. Using a thrombelastograph, we found that blood clots of PAI-1 knockout mice were lysed much more quickly than wild type mice. Additionally, blood clots had less shear elastic modulus strength than clots of normal animals. VLHL PAI-1 treatment of PAI-1 deficient mice extended or prevented thrombus lysis and increased clot strength in a concentration dependent fashion. These two parameters determine the extent of thrombus growth and regression; thus, further testing is anticipated to confirm the effectiveness of plasminogen activator inhibitor with a very long half life in an in vivo model and we hope that this protein can be effective in human PAI-1 deficiency disorder. PMID:19815949

Jankun, Jerzy; Aleem, Ansari M; Struniawski, Rados?aw; Lysiak-Szyd?owska, Wies?awa; Selman, Steven H; Skrzypczak-Jankun, Ewa

2009-01-01

250

A Forkhead/winged helix-related transcription factor mediates insulin-increased plasminogen activator inhibitor-1 gene transcription.  

Science.gov (United States)

Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of fibrinolysis by its inhibition of both tissue-type and urokinase plasminogen activators. PAI-1 levels are elevated in type II diabetes and this elevation correlates with macro- and microvascular complications of diabetes. Insulin increases PAI-1 production in several experimental systems, but the mechanism of insulin-activated PAI-1 transcription remains to be determined. Deletion analysis of the PAI-1 promoter revealed that the insulin response element is between -117 and -7. Mutation of the AT-rich site at -52/-45 abolished the insulin responsiveness of the PAI-1 promoter. This sequence is similar to the inhibitory sequence found in the phosphoenolpyruvate carboxylkinase/insulin-like growth factor-I-binding protein I promoters. Gel-mobility shift assays demonstrated that the forkhead bound to the PAI-1 promoter insulin response element. Expression of the DNA-binding domain of FKHR acted as a dominant negative to block insulin-increased PAI-1-CAT expression. A LexA-FKHR construct was also insulin responsive. These data suggested that a member of the Forkhead/winged helix family of transcription factors mediated the effect of insulin on PAI-1 transcription. Inhibition of phosphatidylinositol 3-kinase reduced the effect of insulin on PAI-1 gene expression, a result consistent with activation through FKHR. However, it was likely that a different member of the FKHR family (not FKHR) mediated this effect since FKHR was present in both insulin-responsive and non-responsive cell lines. PMID:11919188

Vulin, Anthony Igor; Stanley, Frederick M

2002-06-01

251

Expression of the receptor for urokinase-type plasminogen activator in normal and neoplastic blood cells and hematopoietic tissue  

DEFF Research Database (Denmark)

Expression of the receptor for the urokinase type plasminogen activator (uPAR) has been studied by flow cytometry and immunohistology in normal blood and bone marrow cells, in vitro activated lymphoid cells, and tissue samples from reactive lymph nodes (n = 6), thymus (n = 2) and malignant lymphomas (n = 82), or leukemias (n = 32). HL-60 myeloid precursor cells and CD34-positive normal stem cells also were analyzed. In the normal cells, staining was confined to monocytes, macrophages, neutrophils, and myeloid precursors. No labelling was seen of normal or activated lymphoid cells. Purified CD34-positive hematopoietic progenitors were uPAR negative, but expressed uPAR during differentiation in short-term liquid culture stimulated in vitro by recombinant interleukin (IL)-1, IL-3, IL-6, granulocyte-macrophage colony stimulating factor (CSF), granulocyte-CSF, and stem cell factor. Enhanced uPAR expression was also seen in HL-60 cells after induction of differentiation with dimethyl sulfoxide or 1 alpha,25-dihydroxyvitamin D3. In lymphomas and leukemias, the staining pattern was similar to that seen in the normal cells with labelling of monocytic and myeloid that seen in the normal cells with labelling of monocytic and myeloid malignancies, but not of the neoplastic cells in B-cell or T-cell lymphomas or Hodgkin's disease. In conclusion, uPAR is a differentiation marker for myeloid and monocytic cells, and may act to facilitate migration of these cells in normal and pathologic conditions by cell-associated plasminogen activation. Whether expression of uPAR in myeloid and monocytic malignancies relates to their growth and behavior will be an important topic for investigations in the future.

Plesner, T; Ralfkiaer, E

1994-01-01

252

Biochemical actions of glucocorticoids on macrophages in culture. Specific inhibition of elastase, collagenase, and plasminogen activator secretion and effects on other metabolic functions  

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The effects of glucocorticoids on biochemical functions of macrophages from man, mouse, rabbit, and guinea pig were examined. Secretion of plasminogen activator by human peripheral blood monocytes was decreased 50% with 1 nM dexamethasone. Differentiation of murine monocytic and granulocytic colonies in agar from bone marrow precursors was decreased 50% at 7 days with 20 nM dexamethasone. Secretion of elastase, collagenase, and plasminogen activator by resident and thioglycollate-elicited mouse peritoneal macrophages was decreased by dexamethasone, cortisol, and triamcinolone acetonide (1 to 1,000 nM), but not by progesterone, estradiol, and dihydrotestosterone (1,000 nM); in contast, secretion of lysozyme was not affected by glucocorticoids. The inhibition of macrophage secretion by dexamethasone was both time and dose dependent. Inhibition of macrophage secretion increased with increasing glucocorticoid concentration. Half-maximum inhibition of secretion of elastase, collagenase, and plasminogen activator was seen at dexamethasone concentrations (1 to 10 nM) similar to those that half-saturated the specific glucocorticoid receptors. At high concentrations of dexamethasone (100 to 1,000 nM) the secretion of plasminogen activator was inhibited to a greater extent (>95%) than the secretion of elastase (60 to 80%).Progesterone alone had no effect on secretion, but blocked the inhibitory effects of dexamethasone and cortisol. Secretion of collagenase, neutral proteinases, and plasminogen activator by elicited rabbit alveolar macrophages was inhibited with glucocorticoids (0.1 to 100 nM) but not with progesterone or sex steroids. Secretion of a neutral elastinolytic proteinase by guinea pig alveolar macrophages was also inhibited by dexamethasone.

Werb, Z.

1978-01-01

253

Cerebrospinal fluid u-plasminogen activator and matrix metalloproteinase-9 levels in human eosinophilic meningitis associated with angiostrongyliasis.  

Science.gov (United States)

Cerebrospinal fluid (CSF) urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP-9) levels were measured in patients with eosinophilic meningitis associated with angiostrongyliasis (EOMA) by quantitative sandwich enzyme immunoassays. The CSF concentrations of uPA and MMP-9 were evaluated in 30 EOMA patients and 10 controls. The CSF uPA and MMP-9 levels of the EOMA patients were significantly higher than those of the controls (pstiff neck (p=0.048), while the MMP-9 was in correlation with CSF total protein (p=0.006), CSF leukocytosis (p=0.004) and CSF eosinophil numbers (p=0.02). CSF uPA and MMP-9 levels are potentially useful for the understanding of immunologic pathogenesis, for therapeutic targets, for the diagnosis of EOMA and for monitoring treatment efficacy. PMID:20584616

Sanpool, Oranuch; Intapan, Pewpan M; Thanchomnang, Tongjit; Santivarangkana, Taweesak; Niwattayakul, Kanigar; Chotmongkol, Verajit; Maleewong, Wanchai

2010-09-01

254

Loss of heparin-binding protein prevents necrotizing glomerulonephritis: first clues hint at plasminogen activator inhibitor-1.  

Science.gov (United States)

The orchestration of acute inflammatory kidney injury is subject to widespread influences and involves cytokines as well as chemokines released by resident as well as infiltrating cells. Although intense research efforts have been made in the field, it still unravels yet novel key molecules involved in the pathogenesis of this kidney disease. A heparin-binding growth factor denoted midkine is expressed by various cell types following stress of tissue damage. Specific functions relate to orchestration of reparative and inflammatory processes by promoting migration of leucocytes and release of chemokines with ensuing angiogenesis. Midkine appears as a double-edged sword with beneficial or harmful effects in injured tissues. Here, we discuss a recent publication that provides evidence for the beneficial role of midkine in progressive glomerulonephritis, most likely due to blockade of plasminogen activator inhibitor-1 release. PMID:23543126

?alaru, Delia Lidia; Mertens, Peter R; Bartsch, Peter

2013-10-01

255

Cryopreserved recombinant tissue plasminogen activator for the restoration of occluded central venous access devices in pediatric oncology patients  

International Nuclear Information System (INIS)

Thrombolytic therapy with urokinase 5000 units has been the standard therapy for restoration of thrombosed central catheters. However, with the decreased availability of urokinase, alternatives needed to be sought. The aim of the study was to determine the efficacy, bioactivity, dwell time and cost of cryopreserved recombinant tissue plasminogen activator (rTPA) in the restoration of occluded central venous access devices. For children 10kg, a dose of 1 mg was used. The dwell time was 1-2 hours. Of the 40 courses of rTPA, 39 fully restored central venous line patency (97%). Successful courses were instilled for an average of 1 hour. Cryopreserved rTPA appears to be safe and effective in the dose used to restore the patency of occluded central venous access devices in pediatric oncology patients. (author)

256

Fontan patient with plastic bronchitis treated successfully using aerosolized tissue plasminogen activator: a case report and review of the literature.  

Science.gov (United States)

Plastic bronchitis is an uncommon condition characterized by the production of large pale bronchial casts that obstruct the tracheobronchial tree. The cellular content, cohesiveness, and often rubber-like consistency distinguish bronchial casts from the usual mucus plugs found with such disease states as asthma. Plastic bronchitis can be found secondary to many conditions, and a simplified classification scheme organizes it into two groups: an inflammatory type consisting of casts with an eosinophilic inflammatory infiltrate and an acellular type with a predominance of fibrin distinguished by its relative lack of cellular infiltrate, its mucin predominance, and its appearance only in children with congenital cyanotic heart disease. This report describes a 5-year-old girl who experienced plastic bronchitis 3 months after a Fontan procedure for hypoplastic left heart syndrome that was treated successfully with aerosolized tissue plasminogen activator. PMID:19005718

Do, Thomas B; Chu, James M; Berdjis, Farhouch; Anas, Nick G

2009-04-01

257

Inhibition of urokinase plasminogen activator "uPA" activity alters ethanol consumption and conditioned place preference in mice  

Science.gov (United States)

Urokinase plasminogen activator, uPA, is a serine protease implicated in addiction to drugs of abuse. Using its specific inhibitor, B428, we and others have characterized the role of uPA in the rewarding properties of psychostimulants, including cocaine and amphetamine, but none have examined the role of uPA in ethanol use disorders. Therefore, in the current study, we extended our observations to the role of uPA in ethanol consumption and ethanol-induced conditioned place preference. The general aim of the present series of experiments was to investigate the effects of the administration of the B428 on voluntary alcohol intake and ethanol conditioned reward. A two-bottle choice, unlimited-access paradigm was used to compare ethanol intake between vehicle- and 3, 10, and 30 mg/kg B428-administered mice. For this purpose, the mice were presented with an ethanol solution (2.5%–20%) and water, at each concentration for 4 days, and their consumption was measured daily. Consumption of saccharin and quinine solutions was also measured. Systemic administration of B428 dose-dependently decreased ethanol intake and preference. Additionally, B428 mice did not differ from vehicle mice in their intake of graded solutions of tastants, suggesting that the uPA inhibition did not alter taste function. Also, ethanol metabolism was not affected following B428 injection. More importantly, 1.5 g/kg ethanol-induced conditioned place preference acquisition was blocked following B428 administration. Taken together, our results are the first to implicate uPA inhibition in the regulation of ethanol consumption and preference, and suggest that uPA may be considered as a possible therapeutic drug target for alcoholism and abstinence.

Al Maamari, Elyazia; Al Ameri, Mouza; Al Mansouri, Shamma; Bahi, Amine

2014-01-01

258

Autocrine and paracrine up-regulation of blood-brain barrier function by plasminogen activator inhibitor-1.  

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The blood-brain barrier (BBB) is the interface that separates the central nervous system (CNS) from the peripheral circulation. An increase in blood-borne substances including cytokines in plasma and brain affects BBB function, and this is associated with the development of pathogenesis of a number of diseases. Plasminogen activator inhibitor (PAI)-1 regulates the plasminogen activator/plasmin system as a serpin in the periphery and the CNS. We investigated whether PAI-1 alters BBB function using in vitro models of the BBB consisting of rat primary brain endothelial cells (RBECs) alone and co-cultured with pericytes. We found that PAI-1 increased the tightness of the brain endothelial barrier in a time- and dose-dependent manner, as shown by an increase in the transendothelial electrical resistance (TEER) and a decrease in the permeability to sodium fluorescein (Na-F). RBECs responded equally to PAI-1 in the blood-facing and brain-facing sides of the brain, leading to a decrease in Na-F permeability. In addition, RBECs constitutively released PAI-1 into the blood-facing (luminal) and brain-facing (abluminal) sides. This release was polarized in favor of the luminal side and facilitated by serum. The neutralization of PAI-1 by an antibody to PAI-1 in RBEC/pericyte co-culture more robustly reduced TEER of RBECs than in RBEC monolayers. These findings suggest that PAI-1 derived from the neurovascular unit and peripheral vascular system participates as a positive regulator of the BBB in facilitating the barrier function of the endothelial tight junctions. PMID:21036181

Dohgu, Shinya; Takata, Fuyuko; Matsumoto, Junichi; Oda, Masatoshi; Harada, Eriko; Watanabe, Takuya; Nishioku, Tsuyoshi; Shuto, Hideki; Yamauchi, Atsushi; Kataoka, Yasufumi

2011-01-01

259

The Research of Plasminogen Activator Inhibitor-1 Serumic Level to Response One Month Combined Endurance Training and Vitamin E Consumption  

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Full Text Available Introduction & Objective: The plasminogen activator inhibitor-1 (PAI-1 is an important regula-tor of fibrinolysis at sites of vascular injury and has been implicated in the pathogenesis of thrombosis at the arterial sites. The aim of this study was to examine the effect one month aerobic exercise and vitamin E consumption on plasminogen activator inhibitor-1. Materials & Methods: In this quasi experimental study thirty inactive healthy collegiate fe-males voluntarily participated in the study and were randomly divided into three groups: training with vitamin (endurance training accompanied by 400 IU/day vitamin E, vitamin (400 IU/day vitamin E and control (No vitamin and no exercise training. Endurance train-ing included 4 weeks of running on treadmill, 3 days a week. The duration and intensity of exercise in each session for the first week was 30 minutes at 65% of maximum heart rat and for the three remaining weeks were increased by 5 min and 5%, respectively. Two blood samples were taken before and 48 hours after training for measuring PAI-1 antigen. Results: Data analysis revealed that PAI-1 antigen increased in control group significantly (P?0.05, while PAI-1 decreases and increases in training with vitamin, and vitamin groups, respectively were not statistically significant. Changes in PAI-1 were significantly different among the three groups (P?0.05, but using analysis of covariance it was revealed that these differences were due to differences in resting levels of PAI-1. Conclusion: Based on the findings of present study, it could be concluded that short-term regular training combined with vitamin E consumption and chronic vitamin E consumption singly result in improvements in fibrinolytic system due to decrease or prevention of PAI-1 antigen. (Sci J Hamadan Univ Med Sci 2013; 20 (3:247-255

S. Ahmadizad

2013-10-01

260

Two distinct expression patterns of urokinase, urokinase receptor and plasminogen activator inhibitor-1 in colon cancer liver metastases  

DEFF Research Database (Denmark)

Metastatic growth and invasion by colon cancer cells in the liver requires the ability of the cancer cells to interact with the new tissue environment. Plasmin(ogen) is activated on cell surfaces by urokinase-type PA (uPA), and is regulated by uPAR and plasminogen activator inhibitor-1 (PAI-1). To compare the expression patterns of uPA, uPAR and PAI-1 in colon cancer with that in their liver metastases, we analysed matched samples from 14 patients. In all 14 primary colon cancers, we found upregulation of uPAR, uPA mRNA and PAI-1 in primarily stromal cells at the invasive front. In 5 of the 14 liver metastases, we found intense expression of uPAR, uPA-mRNA and PAI-1 in primarily stromal cells at the metastases periphery, and in an expression pattern similar to that found in the primary tumours. In the remaining 9 liver metastases, uPAR and uPA-mRNA were only seen associated with the presence of necrosis within the liver metastases. In addition, PAI-1-immunoreactivity was in all liver metastases seen in hepatocytes at the metastases periphery. Interestingly, the former 5 liver metastases positive for uPAR, uPA mRNA and PAI-1 at the metastasis periphery all had a predominantly desmoplastic reaction, whereas 8 of the remaining 9 showed direct contact between the cancer cells and the liver parenchyma. We conclude that there are 2 distinct patterns of expression of uPAR, uPA and PAI-1 in colon cancer liver metastases and that these correlate closely with 2 morphological growth patterns. These findings may have implication for the treatment of patients with metastatic disease.

Illemann, Martin; Bird, Nigel

2009-01-01

 
 
 
 
261

Tumour Microenvironments Induce Expression of Urokinase Plasminogen Activator Receptor (uPAR) and Concomitant Activation of Gelatinolytic Enzymes  

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Background The urokinase plasminogen activator receptor (uPAR) is associated with poor prognosis in oral squamous cell carcinoma (OSCC), and increased expression of uPAR is often found at the invasive tumour front. The aim of the current study was to elucidate the role of uPAR in invasion and metastasis of OSCC, and the effects of various tumour microenvironments in these processes. Furthermore, we wanted to study whether the cells’ expression level of uPAR affected the activity of gelatinolytic enzymes. Methods The Plaur gene was both overexpressed and knocked-down in the murine OSCC cell line AT84. Tongue and skin tumours were established in syngeneic mice, and cells were also studied in an ex vivo leiomyoma invasion model. Soluble factors derived from leiomyoma tissue, as well as purified extracellular matrix (ECM) proteins, were assessed for their ability to affect uPAR expression, glycosylation and cleavage. Activity of gelatinolytic enzymes in the tissues were assessed by in situ zymography. Results We found that increased levels of uPAR did not induce tumour invasion or metastasis. However, cells expressing low endogenous levels of uPAR in vitro up-regulated uPAR expression both in tongue, skin and leiomyoma tissue. Various ECM proteins had no effect on uPAR expression, while soluble factors originating from the leiomyoma tissue increased both the expression and glycosylation of uPAR, and possibly also affected the proteolytic processing of uPAR. Tumours with high levels of uPAR, as well as cells invading leiomyoma tissue with up-regulated uPAR expression, all displayed enhanced activity of gelatinolytic enzymes. Conclusions Although high levels of uPAR are not sufficient to induce invasion and metastasis, the activity of gelatinolytic enzymes was increased. Furthermore, several tumour microenvironments have the capacity to induce up-regulation of uPAR expression, and soluble factors in the tumour microenvironment may have an important role in the regulation of posttranslational modification of uPAR. PMID:25157856

Magnussen, Synn?ve; Hadler-Olsen, Elin; Latysheva, Nadezhda; Pirila, Emma; Steigen, Sonja E.; Hanes, Robert; Salo, Tuula; Winberg, Jan-Olof; Uhlin-Hansen, Lars; Svineng, Gunbj?rg

2014-01-01

262

A transcription-dependent micrococcal nuclease-resistant fragment of the urokinase-type plasminogen activator promoter interacts with the enhancer.  

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We show the interaction between the enhancer and the minimal promoter of urokinase-type plasminogen activator gene during active transcription by coupling micrococcal nuclease digestion of cross-linked, sonicated chromatin, and chromatin immunoprecipitation. This approach allowed the precise identification of the interacting genomic fragments, one of which is resistant to micrococcal nuclease cleavage. The interacting fragments form a single transcriptional control unit, as indicated by their common protein content. Furthermore, we show that the enhancer-MP interaction persists during the early stages of transcription and is lost upon alpha-amanitin treatment, indicating the requirement for active transcription. Our results support a looping model of interaction between the enhancer and the MP of the urokinase-type plasminogen activator gene. PMID:17331942

Ferrai, Carmelo; Munari, Davide; Luraghi, Paolo; Pecciarini, Lorenza; Cangi, Maria Giulia; Doglioni, Claudio; Blasi, Francesco; Crippa, Massimo P

2007-04-27

263

Induction of urokinase-type plasminogen activator by UV light in human fetal fibroblasts is mediated through a UV-induced secreted protein  

International Nuclear Information System (INIS)

Plasminogen activator was previously shown to be induced by UV light in human cells with low capacity to repair UV-induced DNA lesions. We now show that in human fetal fibroblasts UV light enhanced the two mRNA species coding for the urokinase-type plasminogen activator (uPA) and the tissue-type plasminogen activator, but immunological analysis revealed exclusively uPA activity. Several independent and complementary experiments indicated that induction of uPA was mediated, apparently entirely, through a UV-induced, secreted protein (UVIS) in the growth medium of irradiated cells. First, elevation of uPA mRNA after irradiation was severely blocked by cycloheximide. Second, replacement of conditioned medium in irradiated cells while the rate of plasminogen activator induction was maximal rapidly and completely stopped any further increase in uPA activity. Third, addition of the same removed conditioned medium to nonirradiated cells mimicked UV light in enhancing the level of uPA activity as well as that of uPA mRNA. Fourth, UVIS activity was completely lost by treating the conditioned medium with trypsin but not with nucleases. Kinetic measurements indicated that the accumulation of UVIS rather than the induction of uPA by UVIS conferred the rate-limiting step in the overall process of uPA induction. Both UV light and UVIS acted synergistically with inhibitors of DNA repair for uPA induction. Based on these results, a model is proposed implicating relaxation of DNA torsroposed implicating relaxation of DNA torsional stress of an as yet undefined DNA sequence(s) in the induction of UVIS, which is then responsible for activation of the uPA gene

264

Enhancement of t-PA-mediated plasminogen activation by partially defucosylated glycosaminoglycans from the sea cucumber Stichopus japonicus.  

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Sea cucumber glycosaminoglycan (SC-GAG) was isolated from the body wall of the sea cucumber Stichopus japonicus. The SC-GAG consists of a chondroitin sulfate E-type core polymer with sulfated fucose branches attaching glycosidically to almost every disaccharide unit of the core polymer at the C-3 position of the GlcA or at C-4 and/or C-6 position(s) of GalNAc. SC-GAG was subjected to mild acid-hydrolysis, which cleaved selectively the glycosidic linkages between the core polymer and the fucose branches, resulting in two types of partially defucosylated SC-GAG derivatives. One type (type A), obtained by 3 h-hydrolysis, contained 33% of the fucose branches and the other type (type B), obtained by 6-h hydrolysis, contained 10% of the fucose branches. The molecular masses of types A and B were determined to be 8 and 4 kDa, respectively, by gel permeation HPLC. A chondroitinase ABC (Chase ABC)-digestion demonstrated that types A and B contained 46 and 66% of digestable disaccharide units, respectively, and both types contained 29% of E-type unsaturated disaccharide units bearing no fucose branches. Intact SC-GAG and types A and B were compared for t-PA-mediated plasminogen activation by an in vitro assay system. Although intact SC-GAG and type B exhibited rather weak activity at 6.25 microg/ml, type A exhibited 5 to 10-fold higher activity than intact SC-GAG and type B at the same concentration. The activity of type A was almost one-third that of purified chondroitin sulfate E (127 kDa containing 64.5% E-type disaccharide units) from squid cartilage at 6.25 microg/ml concentration. These results suggest that t-PA-mediated plasminogen activation requires the presence of E-type disaccharide units bearing no fucose branches and a molecular mass larger than 7.5 kDa in terms of the chondroitin sulfate E structure with or without fucose branching. PMID:12153733

Kariya, Yutaka; Sakai, Tokiko; Kaneko, Takuji; Suzuki, Kiyoshi; Kyogashima, Mamoru

2002-08-01

265

Plasminogen carbohydrate side chains in receptor binding and enzyme activation: A study of C6 glioma cells and primary cultures of rat hepatocytes  

International Nuclear Information System (INIS)

The human [Glu1]-plasminogen carbohydrate isozymes, plasminogen type I (Pg 1) and plasminogen type II (Pg 2), were separated by chromatography and studied in cell binding experiments at 4 degrees C with primary cultures of rat hepatocytes and rat C6 glioma cells. In both cell systems, Pg 1 and Pg 2 bound to an equivalent number of receptors, apparently representing the same population of surface molecules. The affinity for Pg 2 was slightly higher. With hepatocytes, the KD for Pg 1 was 3.2 +/- 0.2 microM, and the KD for Pg 2 was 1.9 +/- 0.1 microM, as determined from Scatchard transformations of the binding isotherms. The Bmax was approximately the same for both isozymes. With C6 cells, the KD for Pg 1 was 2.2 +/- 0.1 microM vs. 1.5 +/- 0.2 microM for Pg 2. Again, the Bmax was similar with both isozymes. 125I-Pg 1 and 125I-Pg 2 were displaced from specific binding sites by either nonradiolabeled isozyme. The KI for Pg 2 was slightly lower than the KI for Pg 1 with hepatocytes (0.9 vs. 1.3 microM) and with C6 cells (0.6 vs. 1.1 microM). No displacement was detected with miniplasminogen at concentrations up to 5.0 microM. Activation of Pg 1 and Pg 2 by recombinant two-chain tissue-plasminogen activator (rt-PA) was enhanced by hepatocyte cultures. The enhancing effect was greater with Pg 2. Hepatocyte cultures did not affect the activation of miniplasminogen by rt-PA or the activation of plasminogen by streptokinase. Unlike the hepatocytes, C6 cells did not enhance the aepatocytes, C6 cells did not enhance the activation of plasminogen by rt-PA or streptokinase; however, plasmin generated in the presence of C6 cells reacted less readily with alpha 2-antiplasmin

266

Inhibition of urokinase plasminogen activator “uPA” activity alters ethanol consumption and conditioned place preference in mice  

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Full Text Available Elyazia Al Maamari,* Mouza Al Ameri, Shamma Al Mansouri, Amine Bahi*Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates*These authors contributed equally to this workAbstract: Urokinase plasminogen activator, uPA, is a serine protease implicated in addiction to drugs of abuse. Using its specific inhibitor, B428, we and others have characterized the role of uPA in the rewarding properties of psychostimulants, including cocaine and amphetamine, but none have examined the role of uPA in ethanol use disorders. Therefore, in the current study, we extended our observations to the role of uPA in ethanol consumption and ethanol-induced conditioned place preference. The general aim of the present series of experiments was to investigate the effects of the administration of the B428 on voluntary alcohol intake and ethanol conditioned reward. A two-bottle choice, unlimited-access paradigm was used to compare ethanol intake between vehicle- and 3, 10, and 30 mg/kg B428-administered mice. For this purpose, the mice were presented with an ethanol solution (2.5%–20% and water, at each concentration for 4 days, and their consumption was measured daily. Consumption of saccharin and quinine solutions was also measured. Systemic administration of B428 dose-dependently decreased ethanol intake and preference. Additionally, B428 mice did not differ from vehicle mice in their intake of graded solutions of tastants, suggesting that the uPA inhibition did not alter taste function. Also, ethanol metabolism was not affected following B428 injection. More importantly, 1.5 g/kg ethanol-induced conditioned place preference acquisition was blocked following B428 administration. Taken together, our results are the first to implicate uPA inhibition in the regulation of ethanol consumption and preference, and suggest that uPA may be considered as a possible therapeutic drug target for alcoholism and abstinence.Keywords: B428, CPP, two-bottle choice

Al Maamari E

2014-09-01

267

In vitro expression of long and short ovine prolactin receptors: activation of Jak2/STAT5 pathway is not sufficient to account for prolactin signal transduction to the ovine beta-lactoglobulin gene promoter.  

Science.gov (United States)

The recent finding that sheep had long (l-oPRLR) and short (s-oPRLR) prolactin receptors provided new tools to further explore prolactin signaling to target genes. Here we used CHO cells transfected with l-oPRLR or s-oPRLR cDNAs to compare the activation of known key steps of prolactin signaling by the two receptors. We found that prolactin stimulated l-oPRLR tyrosine phosphorylation, although it lacked the last tyrosine residue found in other long prolactin receptors. In addition, l-oPRLR and s-oPRLR both responded to prolactin stimulation by (1) Janus kinase 2 (Jak2) tyrosine phosphorylation, (2) DNA-binding activation of signal transducer and activator of transcription 5 (STAT5), (3) stimulation of transcription from a promoter made of six repeats of STAT5-responsive sequence. However, although it contains STAT5-binding consensus sequences, the ovine beta-lactoglobulin promoter (-4000 to +40) was transactivated by l-oPRLR, but not by s-oPRLR. Taken together, our results indicate that activation of Jak2/STAT5 pathway alone is not sufficient to account for prolactin-induced transcription of this milk protein gene, and that sequences of its promoter, other than STAT5-specific sequences, account for the opposite transcriptional activation capabilities of l-oPRLR and s-oPRLR. PMID:10514551

Bignon, C; Daniel, N; Belair, L; Djiane, J

1999-10-01

268

The effect of the one-chain to two-chain conversion in tissue plasminogen activator: characterization of mutations at position 275.  

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Tissue plasminogen activator (t-PA) is homologous to other serine proteases and contains an apparent activation cleavage site at arginine 275. It has been demonstrated that this arginine-275 can be replaced with either glutamic acid (Tate, K. M., Higgins, D. L., Holmes, W. E., Winkler, M. E., Heyneker, H. L., and Vehar, G. A. Biochemistry 26, 338-343, 1987) or glycine (Peterson, L. C., Johannessen, M., Foster, D., Kumar, A., and Mulvihill, E. Biochim. Biophys. Acta 952, 245-254, 1988; Boose, J. A., Kuismanen, E., Gerard, R., Sambrook, J. and Gething, M.-J. Biochemistry 28, 635-643, 1989) so that the product of the plasminogen activation reaction, plasmin, can no longer hydrolyze the one-chain form of t-PA to the two-chain form. These "one-chain" t-PA variants had diminished activity, compared to wild-type t-PA, in the absence of a cofactor, but in the presence of the fibrin(ogen) cofactor the two variants had activity similar to wild-type t-PA. In order to compare the effects of all possible substitutions, t-PA variants with each of the other nineteen amino acids besides arginine at position 275 were produced by site-directed mutagenesis. All were recovered from cell culture supernatants completely in the one-chain form, except for R275 (wild-type) and R275K, which were partially converted to the two-chain form. These latter two species could be completely converted to the two-chain form by plasmin. In addition, these two forms showed significantly more plasminogen activating activity in the absence of a fibrin(ogen) cofactor, compared to the other 18 variants. In the presence of a cofactor, all of the t-PA mutants had plasminogen activating activity equivalent to wild-type t-PA, except for R275C. The R275C t-PA had comparatively less clot lysis and fibrin binding activity as well. Presumably the new cysteine in this variant was involved in a mixed disulfide or caused misfolding of the molecule resulting in decreased activity. The difference in the plasminogen activating activity of one- and two-chain forms of t-PA was investigated by determining the apparent Michaelis constants and the apparent turnover numbers for R275E t-PA, which remains in the one-chain form throughout the assay, and two-chain R275 t-PA. The kinetic constants were measured in both the presence and the absence of plasmin-digested fibrinogen.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2139248

Higgins, D L; Lamb, M C; Young, S L; Powers, D B; Anderson, S

1990-02-15

269

The association between the 4G/5G polymorphism in the promoter of the plasminogen activator inhibitor-1 gene and extension of postsurgical calf vein thrombosis.  

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The objective of this study was to evaluate whether the presence of a plasminogen activator inhibitor type 1 (PAI-1) promoter polymorphism 4G/5G could significantly influence the proximal extension of vein thrombosis in spite of anticoagulant treatment in patients with calf vein thrombosis (CVT) following orthopaedic, urological and abdominal surgery. We studied 168 patients with CVT, who had undergone orthopaedic, urological and abdominal surgery, subdivided as follows: first, 50 patients with thrombosis progression; second, 118 patients without thrombosis progression. The 4G/5G polymorphism of the plasminogen activator inhibitor 1 was evaluated in all patients and in 70 healthy matched controls. We also studied PAI-1 activity in plasma. The presence of 4G/5G genotype was significantly increased in the group of patients with the extension of thrombotic lesions and was associated with an increase in CVT extension risk (odds ratio adjusted for sex 2.692; 95% confidence interval 1.302-4.702). Moreover, we observed a significant increase of PAI-1 plasma activity in patients with extension of thrombotic lesion vs. patients without extension (P=0.0001). Patients with 4G/5G genotype in the promoter of the plasminogen activator inhibitor - 1 gene present a higher risk of extension of thrombotic lesions. PMID:23222167

Ferrara, Filippo; Meli, Francesco; Raimondi, Francesco; Montalto, Salvatore; Cospite, Valentina; Novo, Giuseppina; Novo, Salvatore

2013-04-01

270

Fibrinolysis during normal human pregnancy: complex inter-relationships between plasma levels of tissue plasminogen activator and inhibitors and the euglobulin clot lysis time.  

Science.gov (United States)

Although it has been previously considered that blood fibrinolytic capacity is reduced during pregnancy, this has been disputed. Also the mechanisms underlying any change in fibrinolysis in pregnancy require clarification. We have therefore measured the plasma activity of tissue plasminogen activator (t-PA) and inhibitors (t-PAi) and the concentration of the pregnancy specific inhibitor (PA12) antigen, as well as the euglobulin clot lysis time (ECLT) during normal pregnancy. Plasma concentrations of fibrinogen, plasminogen, fibrin(ogen) degradation products (FDP) and cross-linked products (D-dimer) were also monitored. We confirm a marked reduction of the fibrinolytic activity of the plasma euglobulin fraction from the second trimester, and a parallel reduction in t-PA and increase in t-PAi activities, with rapid return to non-pregnant levels post-partum. In contrast, PAI2, whilst undetectable in non-pregnant control plasma, was already measurable in the first trimester, increased through pregnancy, and remained at a high concentration up to at least 48 h post-partum. Fibrinogen and plasminogen concentrations rose progressively through pregnancy and FDP and D-dimer were frequently detectable in late pregnancy plasma. Changes in the ECLT and plasma t-PA and t-PAi activities in pregnancy cannot therefore be directly related to the concentration of PAI2 antigen. Also, despite the apparent marked reduction in fibrinolytic capacity fibrin(ogen) breakdown products are frequently present in increased plasma concentrations in late pregnancy. PMID:3134043

Wright, J G; Cooper, P; Astedt, B; Lecander, I; Wilde, J T; Preston, F E; Greaves, M

1988-06-01

271

Critical role of type 1 plasminogen activator inhibitor (PAI-1) in early host defense against nontypeable Haemophilus influenzae (NTHi) infection.  

Science.gov (United States)

Respiratory systems are constantly being challenged by pathogens. Lung epithelial cells serve as a first line of defense against microbial pathogens by detecting pathogen-associated molecular patterns (PAMPs) and activating downstream signaling pathways, leading to a plethora of biological responses required for shaping both the innate and adaptive arms of the immune response. Acute-phase proteins (APPs), such as type 1 plasminogen activator inhibitor (PAI-1), play important roles in immune/inflammatory responses. PAI-1, a key regulator for fibrinolysis and coagulation, acts as an APP during acute phase response (APR) such as acute lung injury (ALI), inflammation, and sepsis. However, the role of PAI-1 in the pathogenesis of these diseases still remains unclear, especially in bacterial pneumonia. In this study, we showed that PAI-1 expression is upregulated following nontypeable Haemophilus influenzae (NTHi) infection. PAI-1 knockout (KO) mice failed to generate early immune responses against NTHi. Failure of generating early immune responses in PAI-1 KO mice resulted in reduced bacterial clearance and prolonged disease process, which in turn led to enhanced inflammation at late stage of infection. Moreover, we also found that NTHi induces PAI-1 via activation of TLR2-MyD88-MKK3-p38 MAPK signaling pathway. These data suggest that PAI-1 plays critical role in earl host defense response against NTHi infection. Our study thus reveals a novel role of PAI-1 in infection caused by NTHi, one of the most common gram-negative bacterial pathogens in respiratory systems. PMID:21945446

Lim, Jae Hyang; Woo, Chang-Hoon; Li, Jian-Dong

2011-10-14

272

Respiratory burst function of ovine neutrophils  

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Full Text Available Abstract Background Respiratory burst function resulting in the release of reactive oxygen species such as superoxide anion (O2- from neutrophils is one of the key mechanisms of the innate immune system, and maladaptive control of this mechanism is thought to play a pivotal role in the development of pathologies such as acute lung injury and sepsis. Ovine models of these pathologies are limited by the poor understanding of ovine neutrophil respiratory burst function. Results Aspects of ovine neutrophil respiratory burst function to be characterised were: i the maximum rate of O2- generated (Vmax; ii the time taken to reach Vmax; iii the total amount of O2- generated during the reaction; and iv the duration of the reaction. As well as for unstimulated neutrophils, these aspects were also characterised after incubation with a priming agonist (platelet activating factor [PAF], tumour necrosis factor alpha [TNF-?] and lipopolysaccharides [LPS] activating agonists (N-formylmethionyl-leucyl-phenylalanine [fMLP] and phorbol 12-myristate 13-acetate [PMA] or a combination of a priming and an activating agonist. In the absence of priming or activating agonists, ovine neutrophils displayed a low level of respiratory burst function which was not enhanced by either PAF, TNF-?, LPS or fMLP, but was significantly enhanced by PMA. The PMA-induced respiratory burst function was further enhanced by pre-incubation with PAF, but not with TNF-? or LPS. By varying the length of pre-incubation with PAF it was demonstrated that this effect decreased as the duration of pre-incubation with PAF increased, and that PAF was enhancing PMA's effects rather than PMA enhancing PAF's effects. Conclusion This study successfully adapted a commonly used method of measuring human neutrophil respiratory burst function to characterise different aspects of ovine neutrophil respiratory burst function. This improved understanding of ovine neutrophils will facilitate the validitation of ovine biomedical models of human pathologies in which neutrophils have been implicated.

Fraser John F

2009-05-01

273

Induction of oxidative stress and inhibition of plasminogen activator inhibitor-1 production in endothelial cells following exposure to organic extracts of diesel exhaust particles and urban fine particles  

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Endothelial cells play important roles in anticoagulant and fibrinolytic systems. Recent studies suggest that increases in ambient particulate matter (PM) levels have been associated with an increase in mortality rate from cardiovascular diseases. We examined the production of heme oxygenase-1 (HO-1) and factors related to the fibrinolytic function by rat heart microvessel endothelial cells exposed to organic extracts of diesel exhaust particles (OE-DEP) and urban fine particles (OE-UFP) to investigate the direct effects of these soluble organic fractions in these PM on the fibrinolytic function of endothelial cells. The cell monolayer exposed to 10 {mu}g/ml OE-DEP produced a larger amount of HO-1 than cells exposed to 10 {mu}g/ml OE-UFP. OE-DEP and OE-UFP exposure reduced plasminogen activator inhibitor-1 (PAI-1) production by the cells but did not affect the production of thrombomodulin, tissue-type plasminogen activator, or urokinase-type plasminogen activator. Increased PAI-1 synthesis in response to treatment with 1.0 ng/ml tumor necrosis factor-{alpha} or 0.5 ng/ml transforming growth factor-{beta}1 was reduced by OE-DEP exposure. Suppression of PAI-1 production by OE-DEP exposure was mediated through oxidative stress and was independent of HO-1 activity. These results suggest that exposure to the soluble organic fraction of PM and DEP induced oxidative stress and reduced the PAI-1 production of endothelial cells. (orig.)

Furuyama, Akiko; Koike, Eiko [National Institute for Environmental Studies, Inhalation toxicology Team, Tsukuba (Japan); Hirano, Seishiro [National Institute for Environmental Studies, Environmental Health Sciences Division, Tsukuba (Japan); Kobayashi, Takahiro [National Institute for Environmental Studies, Inhalation toxicology Team, Tsukuba (Japan); National Institute for Environmental Studies, Environmental Health Sciences Division, Tsukuba (Japan)

2006-03-15

274

Localization and significance of urokinase plasminogen activator and its receptor in placental tissue from intrauterine, ectopic and molar pregnancies  

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Urokinase plasminogen activator receptor (uPAR) is a membrane-anchored protein with urokinase plasminogen activator (uPA) as the ligand. This complex induces proteolysis and remodelling of maternal decidua during placental implantation. The presence of uPAR on trophoblasts is supposed to promote adhesion, migration and invasion. In cancer tissue, high levels of uPAR are correlated with a poor prognosis. This immunohistochemical study shows the localization of uPA and uPAR in a prospective design with stereological sampling of fetal and maternal tissue from normal, ectopic and hydatidiform molar (HM) pregnancies. Cytokeratin and Ki67 were used as markers for trophoblasts and proliferating cells. Membrane-bound uPAR was observed on villous non-proliferating intermediate trophoblasts (IT) within cell columns in intrauterine and ectopic pregnancies. The corresponding proliferating IT with cytological atypia sprouting from the chorionic villi in HM was uPAR-negative. uPA but not uPAR was observed in anchoring distal IT at the attachment-point to the basal plate. In the placental bed, extravillous interstitial trophoblasts were uPA-positive but uPAR-negative. The trophoblast giant cells were both uPA- and uPAR-negative. In relation to the maternal vessels, a focal distribution for uPA and uPAR was present in the endovascular and perivascular trophoblasts. The intraluminal trophoblasts overlying endothelial cells were uPAR-positive only. In maternal tissue from intrauterine and molar pregnancies, uPAR was seen in the decidual cells in a zone facing the anchoring villi and the fibrinoid lesions with embedded trophoblasts. In contrast, the stromal cells of the fallopian tube without a decidual reaction facing the implanted gestation were uPAR-negative. Non-invaded decidual, myometrial and muscular tissue of the pregnant uterus and fallopian tube was extensively positive for uPA whereas 'pseudodecidual' cells from the intrauterine evacuate in patients with an ectopic pregnancy only showed a focal and scanty reaction for uPA. When trophoblast invasion of the decidua was present, the decidual cells were uPA-negative. A semi-quantitative assessment of the receptor was estimated in villous IT within cell columns in normal and molar pregnancies but, in conclusion, quantitative evaluation of uPAR cannot be used to predict development of post-molar persistent trophoblastic disease (PTD).

Floridon, C; Nielsen, O

1999-01-01

275

Overexpression of SERBP1 (Plasminogen activator inhibitor 1 RNA binding protein in human breast cancer is correlated with favourable prognosis  

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Full Text Available Abstract Background Plasminogen activator inhibitor 1 (PAI-1 overexpression is an important prognostic and predictive biomarker in human breast cancer. SERBP1, a protein that is supposed to regulate the stability of PAI-1 mRNA, may play a role in gynaecological cancers as well, since upregulation of SERBP1 was described in ovarian cancer recently. This is the first study to present a systematic characterisation of SERBP1 expression in human breast cancer and normal breast tissue at both the mRNA and the protein level. Methods Using semiquantitative realtime PCR we analysed SERBP1 expression in different normal human tissues (n?=?25, and in matched pairs of normal (n?=?7 and cancerous breast tissues (n?=?7. SERBP1 protein expression was analysed in two independent cohorts on tissue microarrays (TMAs, an initial evaluation set, consisting of 193 breast carcinomas and 48 normal breast tissues, and a second large validation set, consisting of 605 breast carcinomas. In addition, a collection of benign (n?=?2 and malignant (n?=?6 mammary cell lines as well as breast carcinoma lysates (n?=?16 were investigated for SERBP1 expression by Western blot analysis. Furthermore, applying non-radioisotopic in situ hybridisation a subset of normal (n?=?10 and cancerous (n?=?10 breast tissue specimens from the initial TMA were analysed for SERBP1 mRNA expression. Results SERBP1 is not differentially expressed in breast carcinoma compared to normal breast tissue, both at the RNA and protein level. However, recurrence-free survival analysis showed a significant correlation (P?=?0.008 between abundant SERBP1 expression in breast carcinoma and favourable prognosis. Interestingly, overall survival analysis also displayed a tendency (P?=?0.09 towards favourable prognosis when SERBP1 was overexpressed in breast cancer. Conclusions The RNA-binding protein SERBP1 is abundantly expressed in human breast cancer and may represent a novel breast tumour marker with prognostic significance. Its potential involvement in the plasminogen activator protease cascade warrants further investigation.

Serce Nuran Bektas

2012-12-01

276

An Anti-Urokinase Plasminogen Activator Receptor Antibody (ATN-658) Blocks Prostate Cancer Invasion, Migration, Growth, and Experimental Skeletal Metastasis In Vitro and In Vivo1  

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Urokinase plasminogen activator receptor (uPAR) is a multidomain protein that plays important roles in the growth, invasion, and metastasis of a number of cancers. In the present study, we examined the effects of administration of a monoclonal anti-uPAR antibody (ATN-658) on prostate cancer progression in vitro and in vivo. We examined the effect of treatment of ATN-658 on human prostate cancer cell invasion, migration, proliferation, and regulation of intracellular signaling pathways. For in...

Rabbani, Shafaat A.; Ateeq, Bushra; Arakelian, Ani; Valentino, Maria Luisa; Shaw, David E.; Dauffenbach, Lisa M.; Kerfoot, Christopher A.; Mazar, Andrew P.

2010-01-01

277

Quantitative PET of human urokinase-type plasminogen activator receptor with 64Cu-DOTA-AE105 : implications for visualizing cancer invasion  

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Expression levels of the urokinase-type plasminogen activator receptor (uPAR) represent an established biomarker for poor prognosis in a variety of human cancers. The objective of the present study was to explore whether noninvasive PET can be used to perform a quantitative assessment of expression levels of uPAR across different human cancer xenograft models in mice and to illustrate the clinical potential of uPAR PET in future settings for individualized therapy.

Persson, Morten; Madsen, Jacob

2012-01-01

278

Toxicogenomic analysis of mainstream tobacco smoke-exposed mice reveals repression of plasminogen activator inhibitor-1 gene in heart.  

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Tobacco smoking is associated with cardiovascular pathology. However, the molecular mechanisms of tobacco smoke exposure that lead to initiation or exacerbation of cardiovascular disease are unclear. In this study, the effects of mainstream tobacco smoke (MTS) on global transcription in the heart were investigated. Male C57B1/CBA mice were exposed to MTS from 2 cigarettes daily, 5 days/wk for 6 or 12 wk. Mice were sacrificed immediately, or 6 wk following the last cigarette. High-density DNA microarrays were used to characterize global gene expression changes in whole heart. Fifteen genes were significantly differentially expressed following exposure to MTS. Among these genes, cytochrome P-450 1A1 (Cyp1A1) was upregulated by 12-fold, and Serpine-1 (plasminogen activator inhibitor-1, PAI-1) was downregulated by 1.7-fold. Concomitant increase in Cyp1A1 protein levels and decrease in total and active PAI-1 protein was observed in tissue extracts by Western blot assay and enzyme-linked immunosorbent assay (ELISA), respectively. Observed changes were transient and were partially reversed during break periods. Thus, gene expression profiling of heart tissue revealed a novel cardiovascular mechanism operating in response to MTS. Our results suggest a potential role for PAI-1 in MTS-induced cardiovascular pathology. PMID:18925475

Halappanavar, Sabina; Stampfli, Martin R; Berndt-Weis, Lynn; Williams, Andrew; Douglas, George R; Yauk, Carole L

2009-01-01

279

Genetic association of five plasminogen activator inhibitor-1 (PAI-1) polymorphisms and idiopathic recurrent pregnancy loss in Korean women.  

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Plasminogen activator inhibitor-1 (PAI-1) is important for maintaining pregnancy. Aberrantly increased PAI-1 levels may contribute to thrombosis and inflammation, leading to pregnancy loss. This study investigated the association of PAI-1 polymorphisms (PAI-1 rs2227631 [-844G>A], rs1799889 [-675 4G/5G], rs6092 [43G>A], rs2227694 [9785G>A], and rs7242 [11053T>G]) with idiopathic recurrent pregnancy loss (RPL) in Korean women. We screened 308 RPL patients and 227 control participants for five PAI-1 polymorphisms. Genotyping of PAI-1 was performed by polymerase chain reaction-restriction fragment length polymorphism assay. PAI-1 4G4G and -844AA/4G4G/11053GG genotypes were associated with RPL. PAI-1 -844A/4G/43G/9785G/11053G haplotype was connected to hypofibrinolytic status (i.e. increased levels of plasma PAI-1, increased numbers of platelets, reduced prothrombin time, and reduced activated partial thromboplastin time). Moreover, PAI-1 11053TG+GG frequency was positively related to plasma homocysteine and urate levels, whereas -844AA frequency was associated with plasma folate concentrations according to ordinal logistic regression analysis. Based on these results, we propose that PAI-1 -844G>A, 4G/5G, and 11053T>G polymorphisms are markers of RPL. PMID:23903286

Jeon, Young Joo; Kim, Young Ran; Lee, Bo Eun; Choi, Yi Seul; Kim, Ji Hyang; Shin, Ji Eun; Rah, HyungChul; Cha, Sun Hee; Lee, Woo Sik; Kim, Nam Keun

2013-10-01

280

The human urokinase-plasminogen activator gene (PLAU) is located on chromosome 10q24 centromeric to the HOX11 gene  

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Urokinase-plasminogen activator is one of two soluble serine proteases that are produced by humans and that convert plasminogen, an inactive proenzyme present in plasma and other extracellular fluids, to plasmin, a protease with broad substrate specificities. Its activity is involved in processes requiring localized extracellular proteolysis such as fibrinolysis, tissue remodeling, and cell migration. Increased production of urokinase has been associated with cancer metastases. The gene for urokinase-plasminogen activator, PLAU, was mapped to chromosome 10q24-qter. By employing somatic cell genetics, polymerase chain reaction (PCR), and Southern blot analysis, the authors assign PLAU to chromosome 10q24. Human chromosome segment 10q23-q25 contains the genes for terminal deoxynucleotidyltransferase, cytochrome P450IIC, glutamic-oxaloacetic transaminase, and plasma retinol binding protein, which form a syntenic group on murine chromosome 19. It is therfore of interest that PLAU and glutamate dehydrogenase, which are on murine chromosome 14, also map in or close to this region of human chromosome 10.

Stein, P.M.; Stass, S.A.; Kagan, J. (Univ. of Texas, Houston (United States))

1993-04-01

 
 
 
 
281

Left ventricular apical thrombus after systemic thrombolysis with recombinant tissue plasminogen activator in a patient with acute ischemic stroke  

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Full Text Available Abstract Background Thrombolysis with recombinant tissue plasminogen activator (rtPA is an established treatment in acute stroke. To prevent rethrombosis after rtPA therapy, secondary anticoagulation with heparin is commonly performed. However, the recommended time-point and extent of heparin treatment vary and are not well investigated. Case presentation We report a 61-year-old man who developed an acute global aphasia and right-sided hemiparesis. Cranial CT was normal and systemic thrombolytic therapy with tPA was started 120 minutes after symptom onset. Low-dose subcutaneous heparin treatment was initiated 24 hours later. Transthoracic echocardiography (TTE 12 hours after admission showed slightly reduced left ventricular ejection fraction (LVEF but was otherwise normal. 48 hours later the patient suddenly deteriorated with clinical signs of dyspnea and tachycardia. TTE revelead a large left ventricular apical thrombus as well as a reduction of LVEF to 20 %. Serial further TTE investigations demonstrated a complete resolution of the thrombus and normalisation of LVEF within two days. Conclusion Our case demonstrates an intracardiac thrombus formation following rtPA treatment of acute stroke, probably caused by secondary hypercoagulability. Rethrombosis or new thrombus formation might be an underestimated complication of rtPA therapy and potentially explain cases of secondary stroke progression.

Baumann Gert

2005-05-01

282

The liberated domain I of urokinase plasminogen activator receptor--a new tumour marker in small cell lung cancer.  

Science.gov (United States)

The prognosis of small cell lung cancer (SCLC) remains poor with a 5-year survival rate of 4-6%. In non-small cell lung cancer (NSCLC), high levels of intact and cleaved forms of the receptor for urokinase plasminogen activator (uPAR) are significantly associated with short overall survival. Our aim was therefore to determine the prognostic value of the different uPAR forms in blood from SCLC patients. Serum samples from 92 treatment naive SCLC patients were analysed. Intact uPAR, uPAR(I-III), intact and cleaved uPAR, uPAR(I-III) + uPAR(II-III) and the liberated domain I, uPAR(I) were measured using time-resolved fluorescence immunoassays (TR-FIA 1-3). Assessment of association of the uPAR forms to overall survival (OS) was done using Cox regression analysis adjusted for clinical covariates [age, gender, stage, lactate dehydrogenase (LDH), WHO performance status (PS)]. Multivariate survival analysis demonstrated that high levels of uPAR(I) were significantly (p = 0.009) associated with short overall survival (OS). Patients with uPAR(I) levels above the second tertile had a hazard ratio (HR) of 1.9 (95% confidence interval (CI): 1.1-3.3), compared to patients with levels below the first tertile. High serum uPAR(I) levels are associated with short OS in SCLC patient, independent of LDH and PS. PMID:23030781

Almasi, Charlotte E; Drivsholm, Lars; Pappot, Helle; Høyer-Hansen, Gunilla; Christensen, Ib J

2013-03-01

283

Recanalization characteristics of intracoronary streptokinase compared to intravenous tissue plasminogen activator following acute myocardial infarction: a community hospital experience.  

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This study compares the recanalization characteristics of intracoronary streptokinase (IC-SK) with those of intravenous tissue plasminogen activator (t-PA) in patients with acute myocardial infarction (AMI) treated in the first 6 hours after onset of symptoms. We studied 263 patients with AMI. Among these, 160 were treated with IC-SK; in 59 the drug was given within the first 3 hours and in 101 from 3 to 6 hours. Another 103 patients were treated with IV t-PA; in 64 the drug was given in the first 3 hours and in 39 within 3 to 6 hours. The recanalization rate in the IC-SK group at 0 to 3 hours was 73% and at 3 to 6 hours was 71%, with an overall recanalization rate of 72% from 0 to 6 hours. In the t-PA group, the recanalization rate at 0 to 3 hours was 72% and at 3 to 6 hours was 46%, with an overall recanalization rate of 62%. We conclude that during the first 6 hours of AMI, IC-SK treatment resulted in a rather steady thrombolysis rate, while t-PA treatment with the standard regimen produced a significant decline in recanalization when administered after 3 hours from the onset of AMI symptoms. PMID:7660214

Ramos, R S; Salem, B I; Gowda, S; Haikal, M; Coordes, C; Leidenfrost, R

1995-09-01

284

Plasminogen activator inhibitor-1, factor V, factor II and methylenetetrahydrofolate reductase polymorphisms in women with recurrent miscarriage.  

Science.gov (United States)

The present study investigated the association between genetic polymorphisms of selected thrombophilic factors with recurrent miscarriage (RM). The genetic polymorphisms for plasminogen activator inhibitor-1 4G/5G (PAI-1), Factor V Leiden (FVL), Factor II G20210A (FII) and methylenetetrahydrofolate reductase MTHFR C677T were determined in 186 RM women and 129 healthy women. In RM women, the frequency of heterozygosity for PAI-1 5G/4G (31%) was significantly higher than in controls (5G/4G: 22%) whereas no difference was found in the case of homozygosity 4G/4G and 5G/5G. The frequencies of genotype G/A for FVL and FII were significantly higher in RM women (FVL, 10%; FII, 8%) than in controls (FVL, 3%; FII, 2%). No difference was found in the case of MTHFR C677T. The polymorphisms of FVL and FII should be screened in RM women, whereas PAI-1 seems to be weakly associated with RM. The role of MTHFR C677T polymorphisms without hyperhomocysteinemia appears negligible. PMID:24484533

Pietropolli, A; Giuliani, E; Bruno, V; Patrizi, L; Piccione, E; Ticconi, C

2014-04-01

285

Impact of the 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene on primary nephrotic syndrome.  

Science.gov (United States)

The aim of the present study was to investigate whether the four guanosines (4G)/five guanosines (5G) polymorphism in the gene coding for plasminogen activator inhibitor-1 (PAI-1) affects the clinical features of primary nephrotic syndrome (PNS). A cohort of 200 biopsy-diagnosed PNS patients was studied, with 40 healthy subjects as controls. The PAI-1 gene polymorphism was detected by polymerase chain reaction and DNA sequencing. Associations between the PAI-1 4G/5G polymorphism and clinical features and pathological types of PNS were analyzed. The results indicated that the PAI-1 genotype distribution is significantly different between patients with PNS and healthy controls, with significantly higher numbers of the 4G/4G genotype and lower numbers of the 5G5G genotype detected in PNS patients compared to controls (both Pactivated partial thromboplastin time (APTT) were observed in 4G/4G compared to 5G/5G PNS subjects. The response to steroids was not significantly different among the three genotypes. In conclusion, the 4G allele of the PAI-1 gene appears to be associated with PNS, especially in MN and IgAN patients. These findings suggest that specific targeting may be required for the treatment of PNS patients with the 4G/4G genotype. PMID:24435552

Luo, Yuezhong; Wang, Chao; Tu, Haitao

2014-03-01

286

The liberated domain I of urokinase plasminogen activator receptor--a new tumour marker in small cell lung cancer  

DEFF Research Database (Denmark)

The prognosis of small cell lung cancer (SCLC) remains poor with a 5-year survival rate of 4-6%. In non-small cell lung cancer (NSCLC), high levels of intact and cleaved forms of the receptor for urokinase plasminogen activator (uPAR) are significantly associated with short overall survival. Our aim was therefore to determine the prognostic value of the different uPAR forms in blood from SCLC patients. Serum samples from 92 treatment naive SCLC patients were analysed. Intact uPAR, uPAR(I-III), intact and cleaved uPAR, uPAR(I-III) + uPAR(II-III) and the liberated domain I, uPAR(I) were measured using time-resolved fluorescence immunoassays (TR-FIA 1-3). Assessment of association of the uPAR forms to overall survival (OS) was done using Cox regression analysis adjusted for clinical covariates [age, gender, stage, lactate dehydrogenase (LDH), WHO performance status (PS)]. Multivariate survival analysis demonstrated that high levels of uPAR(I) were significantly (p = 0.009) associated with short overall survival (OS). Patients with uPAR(I) levels above the second tertile had a hazard ratio (HR) of 1.9 (95% confidence interval (CI): 1.1-3.3), compared to patients with levels below the first tertile. High serum uPAR(I) levels are associated with short OS in SCLC patient, independent of LDH and PS.

Almasi, Charlotte E; Drivsholm, Lars

2013-01-01

287

The Effect of Recombinant Tissue Plasminogen Activator (r-tPA on Quantitation of Neutralising Anti-Streptokinase Antibodies  

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Full Text Available The measurement of anti-streptokinase antibodies can distinguish the patients who may benefit from streptokinase and those who should be treated with some other thrombolytic regimen. Neutralising titration test is a commonly used classical assay for measuring anti-streptokinase antibodies and in this assay the ability of anti-streptokinase antibodies in patients' sera in preventing the lytic effect of streptokinase is assessd. As we showed previously the presence of r-tPA in the serum may interefere with the neutralising titration test, we investigated this interference in vitro. The level of neutralising anti-streptokinase antibodies in a serum sample with known levels of the antibodies were measured in absence and presence of increasing amount of r-tPA including therapeutic values. Increasing amount of r-tPA in vitro induced a sudden reduction in the measurable titre of anti-streptokinase antibody levels in a serum with elevated levels of anti-streptokinase antibodies. This effect of r-tPA, which is through activation of plasminogen has not been reported previously. We suggest this assay is unsuitable for clinical diagnosis of anti-streptokinase antibodies.

Afshin Afshari

2004-10-01

288

Subacute Intranasal Administration of Tissue Plasminogen Activator Promotes Neuroplasticity and Improves Functional Recovery following Traumatic Brain Injury in Rats  

Science.gov (United States)

Traumatic brain injury (TBI) is a major cause of death and long-term disability worldwide. To date, there are no effective pharmacological treatments for TBI. Recombinant human tissue plasminogen activator (tPA) is the effective drug for the treatment of acute ischemic stroke. In addition to its thrombolytic effect, tPA is also involved in neuroplasticity in the central nervous system. However, tPA has potential adverse side effects when administered intravenously including brain edema and hemorrhage. Here we report that tPA, administered by intranasal delivery during the subacute phase after TBI, provides therapeutic benefit. Animals with TBI were treated intranasally with saline or tPA initiated 7 days after TBI. Compared with saline treatment, subacute intranasal tPA treatment significantly 1) improved cognitive (Morris water maze test) and sensorimotor (footfault and modified neurological severity score) functional recovery in rats after TBI, 2) reduced the cortical stimulation threshold evoking ipsilateral forelimb movement, 3) enhanced neurogenesis in the dentate gyrus and axonal sprouting of the corticospinal tract originating from the contralesional cortex into the denervated side of the cervical gray matter, and 4) increased the level of mature brain-derived neurotrophic factor. Our data suggest that subacute intranasal tPA treatment improves functional recovery and promotes brain neurogenesis and spinal cord axonal sprouting after TBI, which may be mediated, at least in part, by tPA/plasmin-dependent maturation of brain-derived neurotrophic factor. PMID:25184365

Meng, Yuling; Chopp, Michael; Zhang, Yanlu; Liu, Zhongwu; An, Aaron; Mahmood, Asim; Xiong, Ye

2014-01-01

289

The Thrombolysis in Myocardial Infarction (TIMI) phase II pilot study: tissue plasminogen activator followed by percutaneous transluminal coronary angioplasty.  

Science.gov (United States)

The Thrombolysis in Myocardial Infarction (TIMI) Study Group is investigating whether percutaneous transluminal coronary angioplasty or intravenous beta-receptor blockers, or both, are useful adjuncts to recombinant tissue-type plasminogen activator (rt-PA) in the treatment of patients with acute myocardial infarction (TIMI II study). A total of 317 patients with acute myocardial infarction were treated an average of 2.7 hours after the onset of chest pain during the course of a nonrandomized pilot investigation with 150 mg of rt-PA given over 6 hours. This dose of rt-PA resulted in a high rate of infarct-related coronary artery patency (82 and 87% of patients catheterized an average of either 1 or 32 hours after entry, respectively) and a low 21 day mortality rate of 4.4%. Coronary angioplasty was performed successfully in greater than 90% of patients with appropriate anatomy and in greater than 50% of those treated with rt-PA. In 75 patients treated within 2 hours of the onset of chest pain only 2 (2.7%) were dead by 6 weeks. However, five cases of intracranial hemorrhage were noted, and the rt-PA dose was subsequently reduced to 100 mg given over 6 hours. The TIMI II design and the results of the TIMI II pilot study are discussed. PMID:2889758

Passamani, E; Hodges, M; Herman, M; Grose, R; Chaitman, B; Rogers, W; Forman, S; Terrin, M; Knatterud, G; Robertson, T

1987-11-01

290

A flexible multidomain structure drives the function of the urokinase-type plasminogen activator receptor (uPAR)  

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The urokinase-type plasminogen activator receptor (uPAR) provides a rendezvous between proteolytic degradation of the extracellular matrix and integrin mediated adhesion to vitronectin. These processes are however tightly linked as the high-affinity binding of urokinase regulates the binding of uPAR to matrix-embedded vitronectin. Although crystal structures exist to define the corresponding static bi- and trimolecular receptor complexes it is evident that the dynamic property of uPAR plays a decisive role for its function. In the present study, we combine small angle X-ray scattering, hydrogen-deuterium exchange, and surface plasmon resonance to develop a structural model describing the allosteric regulation of uPAR. We show that the flexibility of its N-terminal domain provides the key for understanding this allosteric mechanism. Importantly, our model has direct implications for understanding uPAR-assisted cell adhesion and migration as well as for translational research including targeted intervention therapy and non-invasive tumor imaging in vivo.

Mertens, Haydyn D.T.; Kjærgaard, Magnus

2012-01-01

291

Haemostatic management of intraoral bleeding in patients with congenital deficiency of alpha2-plasmin inhibitor or plasminogen activator inhibitor-1.  

Science.gov (United States)

Haemostatic management of intraoral bleeding was investigated in patients with congenital alpha2-plasmin inhibitor (alpha2-PI) deficiency or congenital plasminogen activator inhibitor- 1 (PAI-1) deficiency. When extracting teeth from patients with congenital alpha2-PI deficiency, we advocate that 7.5-10 mg kg(-1) of tranexamic acid be administered orally every 6 h, starting 3 h before surgery and continuing for about 7 days. For the treatment of continuous bleeding, such as post-extraction bleeding, 20 mg kg(-1) of tranexamic acid should be administered intravenously, and after achieving local haemostasis 7.5 mg kg(-1) of tranexamic acid should be administered orally every 6 h for several days. In addition, when treating haematoma caused by labial or gingival laceration or buccal or mandibular contusion, haemostasis should be achieved by administering 7.5-10 mg kg(-1) of tranexamic acid every 6 h. Tranexamic acid can also be used for haemostatic management of intraoral bleeding in patients with congenital PAI-1 deficiency, but is less effective when compared with use in patients with congenital alpha2-PI deficiency. Continuous infusion of 1.5 mg kg(-1) h(-1) of tranexamic acid is necessary for impacted tooth extraction requiring gingival incision or removal of local bone. PMID:15357795

Morimoto, Y; Yoshioka, A; Imai, Y; Takahashi, Y; Minowa, H; Kirita, T

2004-09-01

292

Specific identification of Lachesis muta muta snake venom using antibodies against the plasminogen activator enzyme, LV-PA.  

Science.gov (United States)

Sandwich-type enzyme linked immunosorbent assays (ELISA) were developed to detect Lachesis muta muta (bushmaster) snake venom using antibodies against the plasminogen activator enzyme (LV-PA). Antibodies to LV-PA were obtained by immunization of one rabbit with the purified enzyme. The IgG fraction was purified from rabbit blood in a single step on a column of Sepharose-L. m. muta venom and used to coat the microtiter plates. The specificity of the assay was demonstrated by its capacity to correctly discriminate between the circulating antigens in mice that were experimentally inoculated with L. m. muta venom from those in mice inoculated with venoms from Bothrops atrox, B. brazili, B. castelnaudi, Bothriopsis taeniata, B. bilineata, Crotalus durissus ruruima and the antigenic Bothrops (AgB) and Crotalus (AgC) pools venoms used to produce Bothropic and Crotalic antivenoms at Fundacao Ezequiel Dias (FUNED). Measurable absorbance signals were obtained with 1.5 ng of venom per assay. The ELISA was used to follow the kinetic distribution of antigens in experimentally envenomed mice. PMID:15804530

Felicori, Liza F; Chávez-Olórtegui, Carlos; Sánchez, Eladio F

2005-05-01

293

A regulatory hydrophobic area in the flexible joint region of plasminogen activator inhibitor-1, defined with fluorescent activity-neutralizing ligands. Ligand-induced serpin polymerization.  

DEFF Research Database (Denmark)

We have characterized the neutralization of the inhibitory activity of the serpin plasminogen activator inhibitor-1 (PAI-1) by a number of structurally distinct organochemicals, including compounds with environment-sensitive spectroscopic properties. In contrast to latent and reactive center-cleaved PAI-1 and PAI-1 in complex with urokinase-type plasminogen activator (uPA), active PAI-1 strongly increased the fluorescence of the PAI-1-neutralizing compounds 1-anilinonaphthalene-8-sulfonic acid and 4,4'-dianilino-1,1'-bisnaphthyl-5,5'-disulfonic acid. The fluorescence increase could be competed by all tested nonfluorescent neutralizers, indicating that all neutralizers bind to a common hydrophobic area preferentially accessible in active PAI-1. Activity neutralization proceeded through two consecutive steps as follows: first step is conversion to forms displaying substrate behavior toward uPA, and second step is to forms inert to uPA. With some neutralizers, the second step was associated with PAI-1 polymerization. Vitronectin reduced the susceptibility to the neutralizers. Changes in sensitivity to activity neutralization by point mutations were compatible with the various neutralizers having overlapping, but not identical, binding sites in the region around alpha-helices D and E and beta-strand 1A, known to act as a flexible joint when beta-sheet A opens and the reactive center loop inserts as beta-strand 4A during reaction with target proteinases. The defined binding area may be a target for development of compounds for neutralizing PAI-1 in cancer and cardiovascular diseases. Udgivelsesdato: 2001-Apr-20

Egelund, R; Einholm, A P

2001-01-01

294

Bacterial endotoxin enhances colorectal cancer cell adhesion and invasion through TLR-4 and NF-kappaB-dependent activation of the urokinase plasminogen activator system.  

LENUS (Irish Health Repository)

Perioperative exposure to lipopolysaccharide (LPS) is associated with accelerated metastatic colorectal tumour growth. LPS directly affects cells through Toll-like receptor 4 (TLR-4) and the transcription factor NF-kappaB. The urokinase plasminogen activator (u-PA) system is intimately implicated in tumour cell extracellular matrix (ECM) interactions fundamental to tumour progression. Thus we sought to determine if LPS directly induces accelerated tumour cell ECM adhesion and invasion through activation of the u-PA system and to elucidate the cellular pathways involved. Human colorectal tumour cell lines were stimulated with LPS. u-PA concentration, u-PA activity, active u-PA, surface urokinase plasminogen activator receptor (u-PAR) and TLR-4 expression were assessed by ELISA, colorimetric assay, western blot analysis and flow cytometry respectively. In vitro tumour cell vitronectin adhesion and ECM invasion were analysed by vitronectin adhesion assay and ECM invasion chambers. u-PA and u-PAR function was inhibited with anti u-PA antibodies or the selective u-PA inhibitors amiloride or WXC-340, TLR-4 by TLR-4-blocking antibodies and NF-kappaB by the selective NF-kappaB inhibitor SN-50. LPS upregulates u-PA and u-PAR in a dose-dependent manner, enhancing in vitro tumour cell vitronectin adhesion and ECM invasion by >40% (P<0.01). These effects were ameliorated by u-PA and u-PAR inhibition. LPS activates NF-kappaB through TLR-4. TLR-4 and NF-kappaB inhibition ameliorated LPS-enhanced u-PA and u-PAR expression, tumour cell vitronectin adhesion and ECM invasion. LPS promotes tumour cell ECM adhesion and invasion through activation of the u-PA system in a TLR-4- and NF-kappaB-dependent manner.

Killeen, S D

2009-05-19

295

Myeloid-Derived Tissue-Type Plasminogen Activator Promotes Macrophage Motility through FAK, Rac1, and NF-?B Pathways.  

Science.gov (United States)

Macrophage accumulation is one of the hallmarks of progressive kidney disease. Tissue-type plasminogen activator (tPA) is known to promote macrophage infiltration and renal inflammation during chronic kidney injury. However, the underlying mechanism remains largely unknown. We examined the role of tPA in macrophage motility in vivo by tracking fluorescence-labeled bone marrow-derived macrophages, and found that tPA-deficient mice had markedly fewer infiltrating fluorescence-labeled macrophages than the wild-type (WT) mice. Experiments in bone marrow chimeric mice further demonstrated that myeloid cells are the main source of endogenous tPA that promotes macrophage migration. In vitro studies showed that tPA promoted macrophage motility through its CD11b-mediated protease-independent function; and focal adhesion kinase (FAK), Rac-1, and NF-?B were indispensable to tPA-induced macrophage migration as either infection of FAK dominant-negative adenovirus or treatment with a Rac-1-specific inhibitor or NF-?B inhibitor abolished the effect of tPA. Moreover, ectopic FAK mimicked tPA and induced macrophage motility. tPA also activated migratory signaling in vivo. The accumulation of phospho-FAK-positive CD11b macrophages in the obstructed kidneys from WT mice was clearly attenuated in tPA knockout mice, which also displayed lower Rac-1 activity than their WT counterparts. Therefore, our results indicate that myeloid-derived tPA promotes macrophage migration through a novel signaling cascade involving FAK, Rac-1, and NF-?B. PMID:25131752

Lin, Ling; Jin, Yang; Mars, Wendy M; Reeves, W Brian; Hu, Kebin

2014-10-01

296

Regulation of the human plasminogen activator inhibitor type 2 gene: cooperation of an upstream silencer and transactivator.  

Science.gov (United States)

Transcriptional up-regulation of the plasminogen activator inhibitor type-2 (PAI-2) gene is a major response to cellular stress. The expression of PAI-2 is induced by a variety of cytokines and growth factors that act in a cell type- and differentiation stage-dependent manner. We previously reported that the human SERPINB2 gene promoter is controlled by three major transcription regulatory domains: an inducible proximal promoter, an upstream silencer (PAUSE-1), and a distal transactivator region between -5100 and -3300, which appears to overcome inhibition mediated by the silencer. The distal transactivator region is inducible by the phorbol ester PMA, a potent activator of the protein kinase C (PKC) pathway that is a powerful inducer of PAI-2 gene expression in monocytes, macrophages, and myelomonocytic cells as well as in epidermal keratinocytes. Here we show that a 21-bp region (-4952/-4932), containing an AP-1 element, is both necessary and sufficient for PMA-induced transactivator activity in PAI-2-expressing U937 cells. This site specifically binds FosB in PAI-2-expressing U937 cells but not in HeLa cells that do not express PAI-2, and overexpression of FosB, c-Fos, or c-Jun in HeLa cells is sufficient to cause derepression of transcription from the SERPINB2 promoter. Although FosB is likely to be involved in transactivator-mediated derepression of PAI-2 transcription in macrophage-like cells, as exemplified by the U937 cell line, c-Jun may be functional in other cell types. These data suggest a model for the transcriptional control of the human PAI-2 gene and further our understanding of the molecular basis for its tissue-specific expression. PMID:22334683

Stringer, Brett; Udofa, Ekemini A; Antalis, Toni M

2012-03-23

297

Caseinolytic activity of fruit extract from Opuntia ficus-indica on bovine, caprine, and ovine Sodium Caseinates  

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The rates and extents of hydrolysis of RS- and â-caseins from bovine, caprine, and ovine sodium caseinates produced by an enzymatic extract of the fruit of Opuntia ficusindica, (L.) Miller were evaluated and compared with those produced by a commercial animal rennet. A mechanistic model based on a pseudo-first-order enzymatic reaction, in the presence of first-order deactivation of the enzyme, was postulated and successfully fitted to the experimental data. The animal rennet e...

Pintado, Ana I.; Macedo, Angela C.; Teixeira, Grimaneza; Pais, Salome?; Clemente, Alda; Malcata, F. Xavier

2001-01-01

298

Plasminogen activator inhibitor-1 deficiency ameliorates insulin resistance and hyperlipidemia but not bone loss in obese female mice.  

Science.gov (United States)

We previously demonstrated that plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis, is involved in type 1 diabetic bone loss in female mice. PAI-1 is well known as an adipogenic factor induced by obesity. We therefore examined the effects of PAI-1 deficiency on bone and glucose and lipid metabolism in high-fat and high-sucrose diet (HF/HSD)-induced obese female mice. Female wild-type (WT) and PAI-1-deficient mice were fed with HF/HSD or normal diet for 20 weeks from 10 weeks of age. HF/HSD increased the levels of plasma PAI-1 in WT mice. PAI-1 deficiency suppressed the levels of blood glucose, plasma insulin, and total cholesterol elevated by obesity. Moreover, PAI-1 deficiency improved glucose intolerance and insulin resistance induced by obesity. Bone mineral density (BMD) at trabecular bone as well as the levels of osterix, alkaline phosphatase, and receptor activator of nuclear factor ?B ligand mRNA in tibia were decreased by HF/HSD in WT mice, and those changes by HF/HSD were not affected by PAI-1 deficiency. HF/HSD increased the levels of plasma TNF-? in both WT and PAI-1-deficient mice, and the levels of plasma TNF-? were negatively correlated with trabecular BMD in tibia of female mice. In conclusion, we revealed that PAI-1 deficiency does not affect the trabecular bone loss induced by obesity despite the amelioration of insulin resistance and hyperlipidemia in female mice. Our data suggest that the changes of BMD and bone metabolism by obesity might be independent of PAI-1 as well as glucose and lipid metabolism. PMID:24605827

Tamura, Yukinori; Kawao, Naoyuki; Yano, Masato; Okada, Kiyotaka; Matsuo, Osamu; Kaji, Hiroshi

2014-05-01

299

Tissue plasminogen activator induces microglial inflammation via a noncatalytic molecular mechanism involving activation of mitogen-activated protein kinases and Akt signaling pathways and AnnexinA2 and Galectin-1 receptors  

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Inflammatory responses mediated by glial cells play a critical role in many pathological situations related to neurodegeneration such as Alzheimer's disease. Tissue plasminogen activator (tPA) is a serine protease which best-known function is fibrinolysis, but it is also involved in many other physiological and pathological events as microglial activation. Here, we found that tPA is required for Aβ-mediated microglial inflammatory response and tumor necrosis factor-α release. We further...

Serratosa, Joan; Tusell, Josep Maria; Saura, Josep; Planas, Anna M.; Navarro, Pilar

2012-01-01

300

Interactions of plasminogen activator inhibitor-1 with vitronectin involve an extensive binding surface and induce mutual conformational rearrangements  

DEFF Research Database (Denmark)

In order to explore early events during the association of plasminogen activator inhibitor-1 (PAI-1) with its cofactor vitronectin, we have applied a robust strategy that combines protein engineering, fluorescence spectroscopy, and rapid reaction kinetics. Fluorescence stopped-flow experiments designed to monitor the rapid association of PAI-1 with vitronectin indicate a fast, concentration-dependent, biphasic binding of PAI-1 to native vitronectin but only a monophasic association with the somatomedin B (SMB) domain, suggesting that multiple phases of the binding interaction occur only when full-length vitronectin is present. Nonetheless, in all cases, the initial fast interaction is followed by slower fluorescence changes attributed to a conformational change in PAI-1. Complementary experiments using an engineered, fluorescently silent PAI-1 with non-natural amino acids showed that concomitant structural changes occur as well in native vitronectin. Furthermore, we have measured the effect of vitronectin on the rate of insertion of the reactive center loop into beta-sheet A of PAI-1 during reaction with target proteases. With a variety of PAI-1 variants, we observe that both full-length vitronectin and the SMB domain have protease-specific effects on the rate of loop insertion but that the two exhibit clearly different effects. These results support a model for PAI-1 binding to vitronectin in which the interaction surface extends beyond the region of PAI-1 occupied by the SMB domain. In support of this model are recent results that define a PAI-1-binding site on vitronectin that lies outside the somatomedin B domain (Schar, C. R., Blouse, G. E., Minor, K. H., and Peterson, C. B. (2008) J. Biol. Chem. 283, 10297-10309) and the complementary site on PAI-1 (Schar, C. R., Jensen, J. K., Christensen, A., Blouse, G. E., Andreasen, P. A., and Peterson, C. B. (2008) J. Biol. Chem. 283, 28487-28496).

Blouse, Grant E; Dupont, Daniel Miotto

2009-01-01

 
 
 
 
301

Current perspectives on the use of intravenous recombinant tissue plasminogen activator (tPA for treatment of acute ischemic stroke  

Directory of Open Access Journals (Sweden)

Full Text Available Sherita N Chapman,1 Prachi Mehndiratta,1 Michelle C Johansen,1 Timothy L McMurry,2 Karen C Johnston,1,2 Andrew M Southerland1,2 1Department of Neurology, University of Virginia, Charlottesville, VA, USA; 2Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA Abstract: In 1995, the NINDS (National Institute of Neurological Disorders and Stroke tPA (tissue plasminogen activator Stroke Study Group published the results of a large multicenter clinical trial demonstrating efficacy of intravenous tPA by revealing a 30% relative risk reduction (absolute risk reduction 11%–15% compared with placebo at 90 days in the likelihood of having minimal or no disability. Since approval in 1996, tPA remains the only drug treatment for acute ischemic stroke approved by the US Food and Drug Administration. Over the years, an abundance of research and clinical data has supported the safe and efficacious use of intravenous tPA in all eligible patients. Despite such supporting data, it remains substantially underutilized. Challenges to the utilization of tPA include narrow eligibility and treatment windows, risk of symptomatic intracerebral hemorrhage, perceived lack of efficacy in certain high-risk subgroups, and a limited pool of neurological and stroke expertise in the community. With recent US census data suggesting annual stroke incidence will more than double by 2050, better education and consensus among both the medical and lay public are necessary to optimize the use of tPA for all eligible stroke patients. Ongoing and future research should continue to improve upon the efficacy of tPA through more rapid stroke diagnosis and treatment, refinement of advanced neuroimaging and stroke biomarkers, and successful demonstration of alternative means of reperfusion. Keywords: IV tPA, rtPA, t-PA, rt-PA, cerebrovascular disease, cerebrovascular accident

Chapman SN

2014-02-01

302

Hyperacute thrombolysis with recombinant tissue plasminogen activator of acute ischemic stroke: Feasibility and effectivity from an Indian perspective  

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Full Text Available Given the constraints of resources, thrombolysis for acute ischemic stroke (AIS is under evaluation in developing countries like India, especially in areas such as western Utter Pradesh, where it is overly crowded and there is poor affordability. Aim: This study was done to evaluate recombinant tissue plasminogen activator r-tpa in acute ischemic stroke in hyper acute phase, in selected patients of western Utter Pradesh, in terms of feasibility and effectivity. Design: Open, non randomized study. Materials and Methods: Thirty two patients were classified using Trial of ORG 10172 in Acute Stroke treatment (TOAST criteria (large artery atherosclerotic = 8; cardio embolic = 6; small vessel occlusion = 14; other determined etiology = 2; undetermined etiology = 2. The mean time to reach the hospital was 2 h (1.15-3.0, the mean door to CT scan 20 min (10-40 and door to r-tpa injection was 30 min (24-68. The National Institute of Health Stroke Scale (NIHSS scores ranged from 11-22 (mean 15.5 +2.7. The dose of r-tpa administered was 0.9 mg/kg. Results: Twenty one patients (65.6% showed significant improvement on the NIHSS score, at 48 h (4 points. (Mean change = 10; range = 4-17. At one month, 25 (78% recorded improvement on the Barthel index (mean change = 45%. One developed frontal lobe hemorrhage and another developed recurrent stroke; one died of aspiration; and four showed no improvement. Modified Rankin score (m RS was administered at the end of three months to 28 patients (90%; however, the rest could not be directly observed. The average modified Rankin Score was 1.2 (0-2. Conclusions: Hyperacute thrombolysis was found feasible and effective in selected patients with AIS from western Utter Pradesh and who had poor affordability.

Sharma S

2008-01-01

303

Transcatheter Thrombolysis with High-Dose Bolus Tissue Plasminogen Activator in Iatrogenic Arterial Occlusion after Femoral Arterial Catheterization  

International Nuclear Information System (INIS)

Purpose: To assess the efficacy of percutaneous local thrombolysis with high-dose bolus recombinant tissue plasminogen activator (rt-PA) in patients with acute limb ischemia due to arterial thrombosis after cardiac catheterization.Methods: We treated eight patients (7 men; mean age 56 years) with thrombotic occlusion of both the common femoral artery (CFA) and external iliac artery (EIA) in six patients and of the CFA only in two patients. Two 5 mg boluses of rt-PA were injected into the proximal clot through a 5 Fr end-hole catheter and subsequently two additional boluses of 5 mg rt-PA were given through a catheter with multiple side-holes. In case of a significant amount of residual thrombus, a continuous infusion of 2.5 mg/hr of rt-PA was started.Results: Successful lysis was achieved in all patients. The mean duration of lysis was 2 hr 41 min. The mean total amount of rt-PA delivered was 23.16 mg. In four patients unmasked flow-limited dissections confined to the CFA were managed by prolonged balloon dilatation, while in the remaining four patients with extension of the dissection to the external iliac artery one or two Easy Wallstents were implanted. There was prompt relief of lower limb ischemic symptoms and signs in all patients. Two groin hematomas were conservatively treated.Clinical and color Doppler flow imaging follow-up with a mean duration of 15 months, showed no reappearance of ischemic symptoms or development of restenosis in any of the patients. One pf restenosis in any of the patients. One patient died 6 months after thrombolysis.Conclusions: Transcatheter thrombolysis with high-dose bolus rt-PA is a safe and effective treatment inpatients with iatrogenic arterial occlusion after femoral catheterization. Underlying dissections should be treated by prolonged balloon dilatation but stent implantation is often required

304

Clinical experience with recombinant tissue plasminogen activator in the management of intracardiac and arterial thrombosis in children.  

Science.gov (United States)

Thrombotic events may complicate the clinical course of many pediatric diseases. Drugs for therapeutic thrombolysis include streptokinase, urokinase and tissue plasminogen activator (t-PA). There is less experience with recombinant t-PA (rt-PA) in children. We aimed to present our experiences with rt-PA in children with intracardiac or peripheral arterial thrombus. We retrospectively reviewed the children who received rt-PA for thrombus. Twenty-two children (13 boys, 9 girls; age range: 1 day-17 years) with intracardiac (n?=?5), prosthetic heart valve (n?=?2) and peripheral arterial (n?=?15) thrombus were evaluated. Twelve (54%) had congenital heart disease, two (9%) had rheumatic heart disease, three (14%) had leukemia and five (23%) had documented sepsis, prematurity or meconium aspiration syndrome. Ten of the 15 peripheral arterial thromboses were observed following cardiac catheterization. Three of the five intracardiac thrombi were detected in children with leukemia. All children received low-molecular-weight heparin. rt-PA (alteplase) infusion (at a dose of 0.01-0.5?mg/kg per h) was administered for different time periods (3-66?h). Ten of 11 patients with peripheral arterial occlusion and three of five patients with intracardiac thrombus showed full recovery. However, there was no response in two patients with intracardiac thrombus and in two patients with heart valve thrombus. Nose bleeding, melena and decreased serum fibrinogen concentration were observed in seven patients during the rt-PA infusion. All bleedings stopped after cessation of rt-PA infusion, and no blood transfusion was required in any patient. We conclude that rt-PA infusion seems effective and well tolerated in children for the treatment of peripheral arterial and intracardiac thrombus. PMID:24806322

Olgun, Hasim; Buyukavci, Mustafa; Ceviz, Naci; Sahin, Irfan Oguz; Yildirim, Zuhal Keskin; Colak, Abdurrahim; Tekgunduz, Kadir Serafettin; Caner, Ibrahim

2014-10-01

305

Constitutive expression of the urokinase plasminogen activator gene in murine RAW264 macrophages involves distal and 5' non-coding sequences that are conserved between mouse and pig.  

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The 5' flanking regions of the mouse and pig urokinase plasminogen activator (uPA) genes were sequenced and sequence homology interrupted by repeat elements was found to extend to -4.6kb in pig and -6.6kb in mouse. A transient transfection procedure was devised for the murine macrophage cell line RAW264. Pig uPA promoter-CAT constructs were more active than mouse constructs in this assay. This contrast may involve sequence differences within 100 bp of the transcription start site. The selecti...

Cassady, A. I.; Stacey, K. J.; Nimmo, K. A.; Murphy, K. M.; Von Ahe, D.; Pearson, D.; Botteri, F. M.; Nagamine, Y.; Hume, D. A.

1991-01-01

306

Adrenergic Activation of Melatonin Secretion in Ovine Pineal Explants in Short-Term Superfusion Culture Occurs via Protein Synthesis Independent and Dependent Phenomena  

Science.gov (United States)

The ovine pineal is generally considered as an interesting model for the study on adrenergic regulation of melatonin secretion due to some functional similarities with this gland in the human. The present investigations, performed in the superfusion culture of pineal explants, demonstrated that the norepinephrine-induced elevation of melatonin secretion in ovine pinealocytes comprised of two subsequent periods: a rapid increase phase and a slow increase phase. The first one included the quick rise in release of N-acetylserotonin and melatonin, occurring parallel to elevation of NE concentration in the medium surrounding explants. This rapid increase phase was not affected by inhibition of translation. The second, slow increase phase began after NE level had reached the maximum concentration in the culture medium and lasted about two hours. It was completely abolished by the treatment with translation inhibitors. The obtained results showed for the first time that the regulation of N-acetylserotonin synthesis in pinealocytes of some species like the sheep involves the on/off mechanism, which is completely independent of protein synthesis and works very fast. They provided strong evidence pointing to the need of revision of the current opinion that arylalkylamines N-acetyltransferase activity in pinealocytes is controlled exclusively by changes in enzyme abundance. PMID:25133175

2014-01-01

307

Recombinant production of a hybrid plasminogen activator composed of surfactant protein B and low-molecular-weight urokinase.  

Science.gov (United States)

Intraalveolar fibrin deposition is commonly observed during acute inflammatory and chronic interstitial lung diseases and may contribute to impairment of surfactant function and gas exchange. We recently described a chemically cross-linked chimeric protein consisting of surfactant protein (SP)-B and urokinase (uPA) for targeting alveolar fibrin under conditions such as acute respiratory distress syndrome (ARDS) or lung fibrosis. We now investigated the feasibility of a recombinant production of a fusion protein encoding mature SP-B and uPA, termed SPUC. Four different SPUC proteins (N-term SP-B/C-term uPA, N-term uPA/C-term SP-B, each +/- His-tag) were prepared by cloning the cDNA encoding mature SP-B and low-molecular-weight uPA into the expression vector pcDNA3.1. CHO-cells were transfected with the constructs and the supernatant and cell lysates were analyzed for expression of SPUC. Using a chromogenic substrate assay uPA activity was found in supernatants and lysates of transfected cells with highest activities related to the N-term uPA/C-term SP-B (+/- His-tag) construct in supernatants 48h after transfection. Casein enzymography showed an enzymatically active fusion proteins with a molecular weight of approximately 42 kDa in the supernatant of cells transfected with the N-term uPA/C-term SP-B (+/- His-tag) construct, but only a minor activity with the N-term SP-B/C-term uPA construct. The N-term uPA/C-term SP-B construct was also shown to possess higher resistance towards inhibition by plasminogen activator inhibitor-1. We conclude that recombinant production of a fusion protein consisting of mature SP-B and uPA is feasible, when the SP-B moiety is fused to the C-terminus of urokinase. PMID:19132247

Ruppert, Clemens; Mahavadi, Poornima; Wygrecka, Malgorzata; Weaver, Timothy E; Magdolen, Viktor; Idell, Steven; Preissner, Klaus T; Seeger, Werner; Günther, Andreas; Markart, Philipp

2008-12-01

308

Novel patents and cancer therapies for transforming growth factor-beta and urokinase type plasminogen activator: potential use of their interplay in tumorigenesis.  

Science.gov (United States)

Transforming growth factor beta (TGF-?) plays different roles in health and disease. TGF-? has been assumed as a dual factor in tumor growth, since it can repress epithelial tumor development in early stages, while it acts as a tumor promoter in the late stages of tumor progression. The cancer cells, during cancerogenesis, acquire migration and invasion capacities and finally they metastasize. The urokinase type plasminogen activator (uPA) system, comprised of uPA, the cell surface receptor (uPAR) and plasminogen-plasmin, is involved in the proteolytic degradation of the extracellular matrix and it also regulates several critical cellular events by its capacity to trigger the activation of intracellular signaling pathways. This enables the cancer cell survival, its dissemination, and enhancement of cell malignancy during tumor progression. The expression of both uPA and uPAR is finely regulated in normal development, but their expression is deregulated in cancer. TGF-? regulates uPA expression in cancer cells while uPA, by conversion of plasminogen to active form, plasmin, may release TGF-? from its latent state. Thus, these pathways cross-regulate each other by mutual feedback contributing to tumor progression. Here, we review the specific roles and the interplay between TGF-? and uPA system in cancer cells, the current cancer therapies and the novel patents focused mainly on uPA and TGF-beta ligands and their cell surface receptors respectively. Finally, with regard to the mutual activity of uPA and TGF-? in tumorigenesis, the aim of this review is to expose the potentiality of TGF-? and uPA systems as becoming combinatorial targets for therapies and patents. PMID:24827562

Krstic, Jelena; Maslovaric, Irina; Santibanez, Juan F

2014-01-01

309

Tissue Plasminogen Activator alters intracellular sequestration of zinc through interaction with the transporter ZIP4  

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Glutamatergic neurons contain free zinc packaged into neurotransmitter-loaded synaptic vesicles. Upon neuronal activation, the vesicular contents are released into the synaptic space, whereby the zinc modulates activity of postsynaptic neurons though interactions with receptors, transporters and exchangers. However, high extracellular concentrations of zinc trigger seizures and are neurotoxic if substantial amounts of zinc re-enter the cells via ion channels and accumulate in the cytoplasm. T...

Emmetsberger, Jaime; Mirrione, Martine M.; Zhou, Chun; Fernandez-monreal, Monica; Siddiq, Mustafa M.; Ji, Kyungmin; Tsirka, Stella E.

2010-01-01

310

Characterization of the plasminogen activator of herpesvirus-transformed cells and examination of its correlation with the tumorigenic and metastatic ability of in vivo-derived sublines  

International Nuclear Information System (INIS)

Herpes simplex virus type 2-transformed hamster embryo fibroblasts (333-8-9 cells) produce increased amounts of plasminogen activator (PA) compared with normal hamster cells. The 333-8-9 PA activity was quantitated in comparison to a PA standard, urokinase (UK). Using a direct PA assay in which 125I-labeled plasminogen is cleaved, a linear dose-response was seen over a 1000-fold range in UK concentration when plotted on a semi-logarithmic scale. Extracellular PA activity secreted by the HSV-2-transformed cell line, 333-8-9, followed a similar dose-response slop. The optimum pH and osmolarity for detection of the 333-8-9 extracellular PA activity were pH 8.9 and approximately 150 mOsmol, respectively. Secretion of PA by the 333-8-9 cells did not vary significantly on a per cell basis over cell densities ranging from 0.1 to 8.0 x 107 cells/T-75 cm2 flask. This assay was accurate, reproducible, and demonstrated that the 333-8-9 cells produced at least a 20-fold greater amount of PA activity than their normal cell counterparts. Based on the molecular weight (50-58 Kd) of the secreted 333-8-9 cell PA and lack of fibrin stimulation of the PA activity, it is concluded to be a urokinase-type PA

311

Regulation of plasminogen activator inhibitor mRNA levels in lipopolysaccharide-stimulated human monocytes. Correlation with production of the protein.  

Science.gov (United States)

Peripheral blood monocytes are essential participants in processes that require pericellular plasminogen activation, a regulated proteolytic pathway that is greatly influenced by the relative concentrations of urokinase-type plasminogen activator (profibrinolytic) and plasminogen activator inhibitor type 2 (PAI-2) (anti-fibrinolytic). Monocyte synthesis of these molecules is inducible by bacterial lipopolysaccharide (LPS) although PAI-2 production is regulated over a much wider concentration range than is urokinase-type PA. The PAI-2 response of LPS-stimulated monocytes was investigated and found to be biphasic, with a peak of mRNA at 4-6 h after stimulation, a decrement in mRNA levels at 8-10 h, and a secondary increase at 16 h. The primary (early phase) response was studied in detail wherein PAI-2 protein production was found to depend on the levels of PAI-2 mRNA. The profiles of steady-state PAI-2 mRNA levels and PAI-2 protein production were parallel with respect to LPS concentration, time of exposure to LPS, and persistence of the response. PAI-2 mRNA accumulation was inducible by cycloheximide but prevented by actinomycin D. The increase in steady-state PAI-2 mRNA was mediated both by an increase in gene transcription and by stabilization of the mRNA once formed. Therefore, the initial phase of PAI-2 production by LPS-stimulated monocytes is determined by the amount of PAI-2 mRNA in these cells; levels of PAI-2 mRNA are controlled by several mechanisms, allowing for rapid variations in production of this molecule. PMID:1551915

Schwartz, B S; Bradshaw, J D

1992-04-01

312

Primary structure of N-linked carbohydrate chains of a human chimeric plasminogen activator K2tu-PA expressed in Chinese hamster ovary cells  

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A recombinant human plasminogen activator hybrid variant K2tu-PA, expressed in Chinese hamster ovary cells, is partially glycosylated at Asn12 (A chain, kringle-2 domain) and completely glycosylated at Asn247 (B chain, protease domain). After release of the N-linked carbohydrate chains by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F, the oligosaccharides were separated from the protein by gel permeation chromatography, then fractionated by FPLC on Mono Q, followed by HPLC on Li...

Vliegenthart, J. F. G.; Bergwerff, A. A.; Oostrum, J.; Asselbergs, F. A. M.; Bu?rgi, R.; Hokke, C. H.; Kamerling, J. P.

1993-01-01

313

Knock-down of plasminogen-activator inhibitor-1 enhances expression of E-cadherin and promotes epithelial differentiation of human pancreatic adenocarcinoma cells  

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High levels of plasminogen activator inhibitor-1 (PAI-1), which is produced by stromal, endothelial and cancer cells and has multiple complex effects on cancers, correlate with poor cancer prognosis. To more definitively study the role of endogenously produced PAI-1 in human pancreatic adenocarcinoma (PAC) PANC-1 cell line biology, we used anti-PAI-1 shRNA to create stable PAI-1 deficient cells (PD-PANC-1s). PD-PANC-1s exhibited a heterogeneous morphology. While the majority of cells exhibite...

Lupu-meiri, Monica; Geras-raaka, Elizabeth; Lupu, Ruth; Shapira, Hagit; Sandbank, Judith; Segal, Liora; Gershengorn, Marvin C.; Oron, Yoram

2012-01-01

314

Glyceraldehyde-3-Phosphate Dehydrogenase of Streptococcus pneumoniae Is a Surface-Displayed Plasminogen-Binding Protein  

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The recruitment of plasminogen endows the bacterial cell surface of Streptococcus pneumoniae with proteolytic activity. In this study we demonstrate specific plasmin- and plasminogen-binding activity for the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which is located in the cytoplasm as well as on the surface of pneumococci. GAPDH exhibits a high affinity for plasmin and a significantly lower affinity for plasminogen.

Bergmann, Simone; Rohde, Manfred; Hammerschmidt, Sven

2004-01-01

315

Functionally stable plasminogen activator inhibitor-1 in a family with cardiovascular disease and vitiligo.  

Science.gov (United States)

Vitiligo is a common skin condition with a complex pathophysiology characterized by the lack of pigmentation due to melanocyte degeneration. In this study, we investigated PAI-1 antigen (Ag) and activity levels in a 34 year old male with extensive vascular disease, alopecia areata and vitiligo. Fasting PAI-1 Ag and activity levels were measured at 9 a.m. in the subject and family members. Both PAI-1 Ag (67 ± 38 vs. 18.6 ± 6.5 ng/ml, P vitiligo is not known, it is likely due to post-translational modifications or increased binding affinity for a stabilizing cofactor. In conclusion, enhanced stability of PAI-1 may contribute to the pathophysiology of vascular disease and associated melanocyte degeneration. Systemic or local treatment with PAI-1 inhibitors may offer a potential treatment alternative to the near orphan status for vitiligo drug development. PMID:24197654

Agirbasli, Mehmet; Eren, Mesut; Yasar, Songul; Delil, Kenan; Goktay, Fatih; Oner, Ebru Toksoy; Vaughan, Douglas E

2014-07-01

316

Is intravenous recombinant tissue plasminogen activator (r-tPA) safe in patients on Dabigatran?  

Science.gov (United States)

Introduction Dabigatran etexilate is a newly approved oral anticoagulant indicated for stroke prevention in nonvalvular atrial fibrillation. There are no reliable, rapidly available laboratory markers to assess its anticoagulant activity. There is no data on the safety of r-tPA on patients who are on dabigatran and it is not known whether r-tPA is safe in patients who are on dabigatran with a normal activated partial thromboplastin time (aPTT). Case report We report the case of a 59-year-old male who is reported with right hemiparesis and global aphasia. Two days prior to admission he underwent elective cardioversion for atrial fibrillation. He had begun dabigatran at 150 mg BID 3 days before cardioversion. Five days after commencing dabigatran, and 10 h after the last oral dose he presented with these symptoms. Patient fulfilled the criteria for r-tPA including a normal aPTT (30 s), normal prothrombin time (INR = 1.0) and a normal creatinine clearance (glomerular filtration rate >60 mL/min/1.73 m2). A brain CT without contrast was normal. After extensive discussion with the family, with clear understanding of the risks and benefits of such an approach in a patient who has been on dabigatran, consent was obtained, and r-tPA (0.9 mg/kg alteplase) was given. Patient’s hospital course remained uncomplicated and he was discharged 4 days after the initial symptoms to an acute rehabilitation facility and is currently on coumadin with INR therapeutic goal between 2 and 3. Conclusion More studies are needed to asses whether r-tPA might be safe in patients who are on dabigatran with a normal activated partial thromboplastin time and more than 10 h after the last dose. PMID:24920984

Govindarajan, Raghav; Galvez, Nestor

2014-01-01

317

Effects of cytokine-suppressive anti-inflammatory drugs on inflammatory activation in ex vivo human and ovine fetal membranes.  

Science.gov (United States)

Intrauterine infection and inflammation are responsible for the majority of early (Ureaplasma parvum or saline control and subjected to explant culture. The effects of treatment with CSAIDs or vehicle (1% DMSO) on accumulation of PGE2 and cytokines (human interleukin 6 (IL6), IL10 and TNF?; ovine IL8 (oIL8)) were assessed in conditioned media at various time points (3-20 ?h). In human membranes, the IKK? inhibitor TPCA-1 (7 ??M) and p38 MAPK inhibitor SB239063 (20 ??M) administered to the amniotic compartment were the most effective in inhibiting accumulation of cytokines and PGE2 in the fetal compartment. NAC (10 ?mM) inhibited accumulation of PGE2 and IL10 only; NBDI (10 ??M) had no significant effect. In addition to the fetal compartment, SB239063 also exerted consistent and significant inhibitory effects in the maternal compartment. TPCA-1 and SB239063 suppressed oIL8 production, while all CSAIDs tested suppressed ovine PGE2 production. These results support the further investigation of intra-amniotically delivered CSAIDs for the prevention of inflammation-mediated PTB. PMID:24493151

Stinson, Lisa F; Ireland, Demelza J; Kemp, Matthew W; Payne, Matthew S; Stock, Sarah J; Newnham, John P; Keelan, Jeffrey A

2014-03-01

318

Plasminogen activator inhibitor 1: Mechanisms of its synergistic regulation by growth factors  

Energy Technology Data Exchange (ETDEWEB)

My research is on the synergistic regulation of PAI-1 by EGF and TGF-?. The mechanism of synergistic regulation of PAI-1 by EGF and TGF-? are addressed. Methods are described for effective identification of RNA accessible sites for antisense oligodexoxynucleotides (ODNs) and siRNA. In this study effective AS-ODN sequences for both Lcn2 and Bcl2 were identified by in vitro tiled microarray studies. Our results suggest that hybridization of ODN arrays to a target mRNA under physiological conditions might be used as a rapid and reliable in vitro method to accurately identify targets on mRNA molecules for effective antisense and potential siRNA activity in vivo.

Song, Xiaoling

2011-12-01

319

Plasma levels of plasminogen activator inhibitor type 1, factor VIII, prothrombin activation fragment 1+2, anticardiolipin, and antiprothrombin antibodies are risk factors for thrombosis in hemodialysis patients.  

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Patients with end-stage renal disease are prone to hemorrhagic complications and simultaneously are at risk for a variety of thrombotic complications such as thrombosis of dialysis blood access, the subclavian vein, coronary arteries, cerebral vessel, and retinal veins, as well as priapism. The study was devised for the following purposes: (1) to identify the markers of thrombophilia in hemodialyzed patients, (2) to establish a role for antiphospholipid antibodies in thrombosis of the vascular access, (3) to characterize phospholipid antibodies in hemodialysis patients, and (4) to study the effects of dialysis on coagulation cascade. A group of 20 hemodialysis patients with no thrombotic complications (NTC) and 20 hemodialysis patients with thrombotic complications (TC) were studied along with 400 volunteer blood donors. Patients with systemic lupus erythematosus and those with nephrotic syndrome were excluded. All patients underwent a screening prothrombin time, activated partial thromboplastin time, fibrinogen (Fg), coagulation factors of the intrinsic and extrinsic pathways, antithrombin III (AT-III), protein C (PC), protein S (PS), resistance to activated protein C, prothrombin activation fragment 1+2 (F1+2), plasminogen, tissue type plasminogen activator (t-PA), plasminogen tissue activator inhibitor type-1 (PAI-1), anticardiolipin antibodies type M and G (ACA-IgM and ACA-IgG), lupus anticoagulant antibodies, and antiprothrombin antibodies type M and G (aPT-IgM and aPT-IgG). The study showed that PAI-1, F 1+2, factor VIII, ACA-IgM, and aPT-IgM levels were increased significantly over controls both in TC and NTC, however, they could distinguish patients with thrombotic complications from those without, being increased maximally in the former group. The novelty of the study is represented by the significant aPT increase that was observed in non-systemic lupus erythematosus hemodialysis patients, and particularly in those with thrombotic events. In addition, there was a reduction of factor XII during the treatment. It is possible to assume in the TC group and, to a lesser extent, also in the NTC group that endothelial cells liberate PAI-1 in the vascular lumen, which causes hypofibrinolysis. In addition, an excess of factor VIII is activated by endothelial dysfunction with subsequent activation of the coagulation cascade as shown by increased F1+2 and fibrinogen. ACA-IgM, in turn, is capable of interfering with the system of protein C, a potent anticoagulant factor that inactivates cofactors Va and VIIIa. They also induce the expression of procoagulant factors on the surface of the endothelial cells. In conclusion, the hypercoagulable state caused by alterations of coagulation and fibrinolytic factors is a cause of vascular access dysfunction and thrombosis of other vessels. PMID:15490419

Molino, Daniela; De Santo, Natale G; Marotta, Rosa; Anastasio, Pietro; Mosavat, Mahrokh; De Lucia, Domenico

2004-09-01

320

Urokinase plasminogen activator receptor affects bone homeostasis by regulating osteoblast and osteoclast function  

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The uPAR and its ligand uPA are expressed by both osteoblasts and osteoclasts. Their function in bone remodeling is unknown. We report that uPAR-lacking mice display increased BMD, increased osteogenic potential of osteoblasts, decreased osteoclasts formation, and altered cytoskeletal reorganization in mature osteoclasts. INTRODUCTION: Urokinase receptor (uPAR) is actively involved in the regulation of important cell functions, such as proliferation, adhesion, and migration. It was previously shown that the major players in bone remodeling, osteoblasts and osteoclasts, express uPAR and produce urokinase (uPA). The purpose of this study was to investigate the role of uPAR in bone remodeling. MATERIALS AND METHODS: In vivo studies were performed in uPAR knockout (KO) and wildtype (WT) mice on a C57Bl6/SV129 (75:25) background. Bone mass was analyzed by pQCT. Excised tibias were subjected to mechanical tests. UPAR KO calvaria osteoblasts were characterized by proliferation assays, RT-PCR for important proteins secreted during differentiation, and immunoblot for activator protein 1 (AP-1) family members. In vitro osteoclast formation was tested with uPAR KO bone marrow monocytes in the presence of macrophage-colony stimulating factor (M-CSF) and RANKL. Phalloidin staining in osteoclasts served to study actin ring and podosome formation. RESULTS: pQCT revealed increased bone mass in uPAR-null mice. Mechanical tests showed reduced load-sustaining capability in uPAR KO tibias. uPAR KO osteoblasts showed a proliferative advantage with no difference in apoptosis, higher matrix mineralization, and earlier appearance of alkaline phosphatase (ALP). Surface RANKL expression at different stages of differentiation was not altered. AP-1 components, such as JunB and Fra-1, were upregulated in uPAR KO osteoblasts, along with other osteoblasts markers. On the resorptive side, the number of osteoclasts formed in vitro from uPAR KO monocytes was decreased. Podosome imaging in uPAR KO osteoclasts revealed a defect in actin ring formation. CONCLUSIONS: The defective proliferation and differentiation of bone cells, coincident with both aberrant expression of transcription factors and cytoskeletal organization, are typical uPAR-dependent molecular phenotypes, and we have now shown their function in osteoblasts and osteoclasts function in vivo.

Furlan, Federico; Galbiati, Clara

2007-01-01

 
 
 
 
321

Effects of pitavastatin on plasminogen activator inhibitor-1 in hyperlipidemic patients  

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Full Text Available Shosaku Nomura1, Takehito Taniura2, Akira Shouzu3, Seitarou Omoto4, Norihito Inami4, Shinya Fujita1, Takeshi Tamaki1, Takashi Yokoi1, Toshiki Shimizu1, Tomoki Ito11First Department of Internal Medicine, Kansai Medical University, Osaka, Japan; 2Department of Internal Medicine, Ueda Hospital, Osaka, Japan; 3Department of Internal Medicine, Saiseikai Izuo Hospital, Osaka, Japan; 4Second Department of Internal Medicine, Kansai Medical University, Osaka JapanAbstract: The effects of statins on two platelet activation markers, plasiminogen activator inhibitor (PAI-1 and adiponectin, were investigated in 68 patients with hyperlipidemia. The patients were treated with pitavastatin with a dosage of 2 mg daily. The plasma levels of platelet-derived microparticles (PDMP, soluble CD40 ligand (sCD40L, sP-selectin, PAI-1, and adiponectin were measured at baseline and after 6 months of treatment in both groups. In hyperlipidemic patients, the plasma levels were higher in PDMP, sCD40L, sP-selectin, and PAI-1, and lower in adiponectin, compared to the normolipidemic controls. Plasma PDMP and sCD40L were positively correlated, while plasma adiponectin was negatively correlated with the plasma levels of PAI-1. No significant differences were observed in the plasma levels of PDMP, sCD40L, sP-selectin, and PAI-1 before and after treatment. A significant increase in plasma adiponectin levels was observed after 6 months of treatment with pitavastatin. When the patients treated with pitavastatin were divided into two groups according to the adiponectin response to pitavastatin treatment, significant decreases in plasma PAI-1, PDMP, and sCD40L levels were observed after pitavastatin treatment in the responder group. These findings suggest that PDMP, sCD40L, and PAI-1 may participate in the development of atherothrombosis in patients with hyperlipidemia, and that pitavastatin may exert an adiponectin-dependent anti-atherothrombotic effect in hyperlipidemic patients.Keywords: hyperlipidemia, PAI-1, pitavastatin, adiponectin, atherothrombosis

Ito T

2012-06-01

322

Phorbol ester stimulates the synthesis and phosphorylation of a 48 kDA-intra-cellular protein in plasminogen activator secreting melanoma cells  

International Nuclear Information System (INIS)

Phorbol ester (12-O-tetradecanoyl-phorbol 13-acetate) stimulates the secretion of tissue-type plasminogen activator by the melanoma cell line, Bowes. This effect is associated with increased levels of mRNAs for both tissue-type plasminogen activator and a 48 KDa-protein. Labelling of melanoma cells with L-[32S]methionine allowed to identify an intracellular protein which was identical with the in vitro translation product of the 48 kDa-protein mRNA. As detectable by L-[35S]methionine labelling, the protein was mainly localized in the cytosol. In vitro phosphorylation reactions, carried out on subcellular fractions revealed a membrane-associated protein which also had the characteristics of the 48 kDa-protein. Phosphorylation did not require Ca2+-ions. Reconstitution experiments between membrane and cytosol fractions of phorbol ester-treated and untreated cells showed that the 48 kDa protein occurs in a cytosolic, unphosphorylated and a membrane-bound, phosphorylated form and that the former is converted to the latter by a phorbol ester activated, membrane-associated protein kinase

323

Para-aminobenzamidine linked regenerated cellulose membranes for plasminogen activator purification: effect of spacer arm length and ligand density.  

Science.gov (United States)

Despite membrane-based separations offering superior alternative to packed bed chromatographic processes, there has been a substantial lacuna in their actual application to separation processes. One of the major reasons behind this is the lack of availability of appropriately modified or end-group modifiable membranes. In this paper, an affinity membrane was developed using a commercially available serine protease inhibitor, para-aminobenzamidine (pABA). The membrane modification was optimized for protein binding capacity by varying: (i) the length of the spacer arm (SA; 5-atoms, 7-atoms, and 14-atoms) linking the ligand to membrane surface; (ii) the affinity ligand (pABA) density on membrane surface (5-25nmol/cm(2)). Resulting membranes were tested for their ability to bind plasminogen activators (PAs) from mono- and multi-component systems in batch mode. The membrane containing pABA linked through 7-atoms SA but similar ligand density as in the case of 5- or 14-atoms long SA was found to bind up to 1.6-times higher amounts of PA per nmoles of immobilized ligand from conditioned HeLa cell culture media. However, membranes with similar ligand densities but different lengths of SA, showed comparable binding capacities in mono-component system. In addition, the length of SA did not affect the selectivity of the ligand for PA. A clear inverse linear correlation was observed between ligand density and binding capacity until the point of PA binding optima was reached (11±1.0nmol/cm(2)) in mono- and multi-component systems for 7- as well as 14-atoms SA. Up to 200-fold purification was achieved in a single step separation of PA from HeLa conditioned media using these affinity membranes. The issues of ligand leaching and reuse of the membranes were also investigated. An extensive regeneration procedure allowed the preservation of approximately 95% of the PA binding capacity of the membranes even after five cycles of use. PMID:23703544

Fasoli, Ezio; Reyes, Yiaslin Ruiz; Guzman, Osiris Martinez; Rosado, Alexandra; Cruz, Vivian Rodriguez; Borges, Amaris; Martinez, Edmarie; Bansal, Vibha

2013-07-01

324

Prognostic value analysis of urokinase-type plasminogen activator receptor in oral squamous cell carcinoma: an immunohistochemical study  

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Full Text Available Abstract Background Oral squamous cell carcinoma (OSCC represents the most common oral malignancy. Despite recent advances in therapy, up to 50% of the cases have relapse and/or metastasis. There is therefore a strong need for the identification of new biological markers able to predict the clinical behaviour of these lesions in order to improve quality of life and overall survival. Among tumour progression biomarkers, already known for their involvement in other neoplasia, a crucial role is ascribed to the urokinase-type plasminogen activator receptor (uPAR, which plays a multiple role in extracellular proteolysis, cell migration and tissue remodelling not only as a receptor for the zymogen pro-uPA but also as a component for cell adhesion and as a chemoattractant. The purpose of this study was to gain information on the expression of uPAR in OSCC and to verify whether this molecule can have a role as a prognostic/predictive marker for this neoplasia. Methods In a retrospective study, a cohort of 189 OSCC patients was investigated for uPAR expression and its cellular localization by immunohistochemistry. As standard controls, 8 normal oral mucosal tissues free of malignancy, obtained from patients with no evidence or history of oral cavity tumours, were similarly investigated. After grouping for uPAR expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G, tumour size, recurrence, TNM staging and overall survival rate. Results In our immunohistochemical study, 74 cases (39.1% of OSCC showed a mostly cytoplasmic positivity for uPAR, whereas 115 were negative. uPAR expression correlated with tumour differentiation grade and prognosis: percentage of positive cases was the greatest in G3 (70.4% and patients positives for uPAR expression had an expectation of life lower than those for uPAR negatives. Conclusion The results obtained in this study suggest a role of uPAR as a potential biomarker useful to identify higher risk subgroups of OSCC patients.

Rocchetti Romina

2008-08-01

325

Plasminogen activator inhibitor type 1 gene is located at region q21. 3-q22 of chromosome 7 and genetically linked with cystic fibrosis  

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The regional chromosomal location of the human gene for plasminogen activator inhibitor type 1 (PAI1) was determined by three independent methods of gene mapping. PAI1 was localized first to 7cen-q32 and then to 7q21.3-q22 by Southern blot hybridization analysis of a panel of human and mouse somatic cell hybrids with a PAI1 cDNA probe and in situ hybridization, respectively. The authors frequent HindIII restriction fragment length polymorphism (RFLP) of the PAI1 gene with an information content of 0.369. In family studies using this polymorphism, genetic linkage was found between PAI1 and the loci for erythropoietin (EPO), paraoxonase (PON), the met protooncogene (MET), and cystic fibrosis (CF), all previously assigned to the middle part of the long arm of chromosome 7. The linkage with EPO was closest with an estimated genetic distance of 3 centimorgans, whereas that to CF was 20 centimorgans. A three-point genetic linkage analysis and data from previous studies showed that the most likely order of these loci is EPO, PAI1, PON, (MET, CF), with PAI1 being located centromeric to CF. The PAI1 RFLP may prove to be valuable in ordering genetic markers in the CF-linkage group and may also be valuable in genetic analysis of plasminogen activation-related diseases, such as certain thromboembolic disorders and cancer.

Klinger, K.W.; Winqvist, R.; Riccio, A.; Andreasen, P.A.; Sartorio, R.; Nielsen, L.S.; Stuart, N.; Stanislovitis, P.; Watkins, P.; Douglas, R.

1987-12-01

326

Plasminogen activator inhibitor type 1 gene is located at region q21.3-q22 of chromosome 7 and genetically linked with cystic fibrosis  

International Nuclear Information System (INIS)

The regional chromosomal location of the human gene for plasminogen activator inhibitor type 1 (PAI1) was determined by three independent methods of gene mapping. PAI1 was localized first to 7cen-q32 and then to 7q21.3-q22 by Southern blot hybridization analysis of a panel of human and mouse somatic cell hybrids with a PAI1 cDNA probe and in situ hybridization, respectively. The authors frequent HindIII restriction fragment length polymorphism (RFLP) of the PAI1 gene with an information content of 0.369. In family studies using this polymorphism, genetic linkage was found between PAI1 and the loci for erythropoietin (EPO), paraoxonase (PON), the met protooncogene (MET), and cystic fibrosis (CF), all previously assigned to the middle part of the long arm of chromosome 7. The linkage with EPO was closest with an estimated genetic distance of 3 centimorgans, whereas that to CF was 20 centimorgans. A three-point genetic linkage analysis and data from previous studies showed that the most likely order of these loci is EPO, PAI1, PON, (MET, CF), with PAI1 being located centromeric to CF. The PAI1 RFLP may prove to be valuable in ordering genetic markers in the CF-linkage group and may also be valuable in genetic analysis of plasminogen activation-related diseases, such as certain thromboembolic disorders and cancer

327

Inhibition of plasminogen activator inhibitor-1 binding to endocytosis receptors of the low-density-lipoprotein receptor family by a peptide isolated from a phage display library  

DEFF Research Database (Denmark)

The functions of the serpin PAI-1 (plasminogen activator inhibitor-1) are based on molecular interactions with its target proteases uPA and tPA (urokinase-type and tissue-type plasminogen activator respectively), with vitronectin and with endocytosis receptors of the low-density-lipoprotein family. Understanding the significance of these interactions would be facilitated by the ability to block them individually. Using phage display, we have identified the disulfide-constrained peptide motif CFGWC with affinity for natural human PAI-1. The three-dimensional structure of a peptide containing this motif (DVPCFGWCQDA) was determined by liquid-state NMR spectroscopy. A binding site in the so-called flexible joint region of PAI-1 was suggested by molecular modelling and validated through binding studies with various competitors and site-directed mutagenesis of PAI-1. The peptide with an N-terminal biotin inhibited the binding of the uPA-PAI-1 complex to the endocytosis receptors low-density-lipoprotein-receptor-related protein 1A (LRP-1A) and very-low-density-lipoprotein receptor (VLDLR) in vitro and inhibited endocytosis of the uPA-PAI-1 complex in U937 cells. We conclude that the isolated peptide represents a novel approach to pharmacological interference with the functions of PAI-1 based on inhibition of one specific molecular interaction.

Jensen, Jan Kristian; Malmendal, Anders

2006-01-01

328

Inhibition of plasminogen activator inhibitor-1 binding to endocytosis receptors of the low density lipoprotein receptor family by a peptide isolated from a phage displayed library  

DEFF Research Database (Denmark)

The functions of the serpin plasminogen activator inhibitor-1 (PAI-1) are based on molecular interactions with its target proteases urokinase-type and tissue-type plasminogen activator (uPA and tPA), with vitronectin, and with endocytosis receptors of the low density lipoprotein family. Understanding the significance of these interactions would be facilitated by the ability to block them individually. Using phage display, we have identified the disulphide constrained peptide motif CFGWC with affinity for natural human PAI-1. The three-dimensional structure of a peptide containing this motif (DVPCFGWCQDA) was determined by NMR. A binding site in the so-called flexible joint region of PAI-1 was suggested by molecular modelling and validated through binding studies with various competitors and site-directed mutagenesis of PAI-1. The peptide with an N-terminal biotin inhibited the binding of the uPA-PAI-1 complex to the endocytosis receptors low density lipoprotein receptor-related protein (LRP-1A) and very low density lipoprotein receptor (VLDLR) in vitro and inhibited endocytosis of the uPA-PAI-1 complex in U937 cells. We conclude that the isolated peptide represents a novel approach to pharmacological interference with the functions of PAI-1 based on inhibition of one specific molecular interaction.

Jensen, Jan K.; Malmendal, Anders

2006-01-01

329

Inhibitory effect of berberine on the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2  

International Nuclear Information System (INIS)

Berberine, a compound isolated from medicinal herbs, has been reported with many pharmacological effects related to anti-cancer and anti-inflammation capabilities. In this study, we observed that berberine exerted a dose- and time-dependent inhibitory effect on the motility and invasion ability of a highly metastatic A549 cells under non-cytotoxic concentrations. In cancer cell migration and invasion process, matrix-degrading proteinases are required. A549 cell treated with berberine at various concentrations showed reduced ECM proteinases including matrix metalloproteinase-2 (MMP2) and urokinase-plasminogen activator (u-PA) by gelatin and casein zymography analysis. The inhibitory effect is likely to be at the transcriptional level, since the reduction in the transcripts levels was corresponding to the proteins. Moreover, berberine also exerted its action via regulating tissue inhibitor of metalloproteinase-2 (TIMP-2) and urokinase-plasminogen activator inhibitor (PAI). The upstream mediators of the effect involved c-jun, c-fos and NF-?B, as evidenced by reduced phosphorylation of the proteins. These findings suggest that berberine possesses an anti-metastatic effect in non-small lung cancer cell and may, therefore, be helpful in clinical treatment

330

A randomized placebo-controlled trial of combined early intravenous captopril and recombinant tissue-type plasminogen activator therapy in acute myocardial infarction.  

Science.gov (United States)

The adjunctive use of intravenous captopril with tissue plasminogen activator early during acute myocardial infarction offers theoretic advantages of diminishing left ventricular volume, preventing ventricular dilation and improving patient survival. To test the safety and efficacy of combined early administration of intravenous captopril and recombinant tissue-type plasminogen activator (rt-PA), 38 patients treated with rt-PA 3 +/- 0.3 h (mean +/- SE) after the onset of myocardial infarction were randomized to intravenous followed by oral captopril or placebo therapy. They underwent cardiac catheterization with measurement of hemodynamic variables and left ventricular function and determination of serum renin, angiotensin and aldosterone levels on days 1 and 7. Oral administration of the selected agent was continued for 3 months along with other antianginal medications, including nonangiotensin-converting enzyme inhibitor vasodilators. Repeat measurements of left ventricular function were obtained before hospital discharge and at 3 months. There were no significant differences in baseline clinical characteristics between groups. One patient in the captopril-treated group became hypotensive during intravenous therapy, requiring discontinuation of treatment. Compared with the placebo-treated group, the captopril-treated group had significant reductions at day 7 in left ventricular end-diastolic pressure (22.5 +/- 1.5 versus 16.3 +/- 1.6 mm Hg, p less than 0.01) and mean systemic arterial pressure (93.6 +/- 3.3 versus 86.2 +/- 2.7 mm Hg, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1825097

Nabel, E G; Topol, E J; Galeana, A; Ellis, S G; Bates, E R; Werns, S W; Walton, J A; Muller, D W; Schwaiger, M; Pitt, B

1991-02-01

331

Modulation of urokinase-type plasminogen activator and metalloproteinase activities in cultured mouse mammary-carcinoma cells: enhancement by paclitaxel and inhibition by nocodazole.  

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Paclitaxel is a potent anti-tumor drug used in the treatment of breast cancer. It induces de-centralization of the microtubular system in tumor cells, blocking cell division. In the search for dissemination to a secondary site, cancer cells are capable of degrading most components of the extracellular matrix via an extracellular proteolytic cascade, including urokinase-type plasminogen activator (uPA) and the matrix metalloproteinases (MMPs). In the present study, the effects of paclitaxel and nocodazole, 2 drugs known to affect microtubules with opposite mechanisms of action, have been tested for their effect on the secretion of uPA and MMPs in cultures of F3II mouse mammary-tumor cells. Tumor-derived uPA activity significantly increased after pre-treatment of tumor cells for 24 hr with micromolar concentrations of paclitaxel (4 microM), while decreasing after pre-treatment with nocodazole (1 microM). A similar modulation was found for MMP-9 by zymographic analysis. Immunofluorescence and Western-blot analysis confirmed the formation of parallel microtubule fragments in paclitaxel-treated cells and almost complete de-polymerization of microtubules in nocodazole-treated ones. Our data suggest that, through opposite actions on microtubule organization and dynamics, paclitaxel and nocodazole exert inverse modulation of tumor-derived proteolytic activity in mammary tumor cells. PMID:10471534

Alonso, D F; Farina, H G; Arregui, C; Aon, M A; Gomez, D E

1999-10-01

332

[Val709-Glu724 streptokinase binding site on plasminogen interacts with streptokinase sequence Thr361-Arg372 during plasminogen-streptokinase complex formation].  

Science.gov (United States)

Localization of the human plasminogen binding site on the streptokinase of complementary Val709-Glu724 plasminogen being crucial one in providing for the plasminogen streptokinase complex activity has been investigated. Experiments were performed with streptokinase fragments and synthetic decapeptides, antiplasminogen monoclonal anti-body IV-1c and synthetic peptide corresponding to Val709-Gly718 sequence of human plasminogen. It was found that plasminogen sequence Val709-Glu724 interacted with Thr361-Arg372 sequence of strepto-kinase. PMID:10791070

Korol'chuk, V I

1999-01-01

333

High levels of tissue plasminogen activator (tPA antigen precede the development of type 2 diabetes in a longitudinal population study. The Northern Sweden MONICA Study  

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Full Text Available Abstract Background Impaired fibrinolysis is found in impaired glucose tolerance and type 2 diabetes, associated with components of the metabolic syndrome. There are no data concerning fibrinolysis in subjects with normal glucose tolerance that convert to diabetes. Methods We studied the activities of tissue plasminogen activator (tPA and plasminogen activator inhibitor-1 (PAI-1 and the levels of tPA antigen (a marker of endothelial dysfunction in 551 subjects with normal glucose tolerance in 1990 in relation to incident diabetes during nine years of follow-up. Results Subjects with diabetes at follow-up (n = 15 had significantly lower baseline tPA activity and higher PAI-1 activity and tPA antigen than non-converters. The risk of diabetes increased linearly across quartiles of PAI-activity (p = 0.007 and tPA antigen (p p = 0.026. The risk of diabetes with low tPA activity or high PAI-1 activity persisted after adjustment for age and sex but diminished to a non-significant level after further adjustments. The odds ratio of diabetes for high tPA antigen was 10.4 (95% confidence interval 2.7–40 adjusted for age and sex. After further adjustment for diastolic blood pressure, waist circumference, insulin, triglycerides, fasting and post load glucose the odds ratio was 6.5 (1.3–33, p = 0.024. Conclusions Impaired fibrinolysis and endothelial dysfunction are evident in subjects with normal glucose tolerance who later develop diabetes. High tPA antigen is predictive of future diabetes independent from the metabolic syndrome.

Jansson Jan-Håkan

2003-12-01

334

Effect of growth factors and lactogenic hormones on expression of plasminogen activator-related genes and cell proliferation in a bovine mammary epithelial cell line.  

Science.gov (United States)

There is conflicting evidence in the literature as to whether up-regulation of urokinase plasminogen activator (u-PA) expression is related to bovine mammary epithelial cell growth. The role of u-PA receptor (u-PAR) and that of the plasminogen activator inhibitors type 1 and type 2 (PAI-1 and PAI-2) in bovine mammary epithelial cell proliferation is not known. The effect of growth factors and various hormones known to affect mammary function on expression of u-PA, u-PAR, PAI-1, PAI-2 and cell proliferation using the BME-UV1 bovine mammary epithelial cell line was examined. Cell proliferation was measured using the MTT assay and direct cell enumeration. Results showed that both IGF-1 and EGF increased cell proliferation but EGF was a more potent mitogen than IGF-1. Furthermore, IGF-1 increased by 2-fold expression of both u-PA and u-PAR while EGF increased by 3·8-fold the expression of only u-PAR. Both growth factors had no effect on expression of PAI-1 and PAI-2. In a manner consistent with changes in gene expression, EGF and to a lesser extent IGF-1 up-regulated total cell associated, membrane-bound and secreted u-PA activity. Thus, a strong correlation exists between u-PAR gene expression along with the activity of u-PA present on cell membranes and cell proliferation. Dexamethasone, prolactin and surprisingly insulin had no effect on cell proliferation. Dexamethasone alone and when combined with insulin or prolactin up-regulated gene expression of both PAI- and PAI-2 but not that of u-PA and u-PAR. Decreased total cell-associated, membrane-bound and secreted u-PA activity was detected in cells cultured in the presence of dexamethasone when combined with insulin or prolactin. However no such effect was observed in the presence of dexamethasone alone. Thus, dexamethasone acting synergistically with prolactin or insulin inhibits the activation of the plasmin-plasminogen system but this inhibition is not correlated with any changes in cell proliferation. PMID:21774863

Theodorou, Georgios; Pecorini, Chiara; Rebucci, Raffaella; Saccone, Francesca; Lecchi, Christina; Politis, Ioannis; Baldi, Antonella

2011-08-01

335

Targeting tumor cell invasion and dissemination in vivo by an aptamer that inhibits urokinase-type plasminogen activator through a novel multifunctional mechanism  

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Data accumulated over the latest two decades have established that the serine protease urokinase-type plasminogen activator (uPA) is a potential therapeutic target in cancer. When designing inhibitors of the proteolytic activity of serine proteases, obtaining sufficient specificity is problematic, because the topology of the proteases' active sites are highly similar. In an effort to generate highly specific uPA inhibitors with new inhibitory modalities, we isolated uPA-binding RNA aptamers by screening a library of 35 nucleotides long 2'-fluoro-pyrimidine RNA molecules using a version of human pro-uPA lacking the epidermal growth factor-like and kringle domains as bait. One pro-uPA-binding aptamer sequence, referred to as upanap-126, proved to be highly specific for human uPA. Upanap-126 delayed the proteolytic conversion of human pro-uPA to active uPA, but did not inhibit plasminogen activation catalyzed by two-chain uPA. The aptamer also inhibited the binding of pro-uPA to uPAR and the binding of vitronectin to the preformed pro-uPA/uPAR complex, both in cell-free systems and on cell surfaces. Furthermore, upanap-126 inhibited human tumor cell invasion in vitro in the Matrigel assay and in vivo in the chick embryo assay of cell escape from microtumors. Finally, upanap-126 significantly reduced the levels of tumor cell intravasation and dissemination in the chick embryo model of spontaneous metastasis. Together, our findings show that usage of upanap-126 represents a novel multifunctional mechanistic modality for inhibition of uPA-dependent processes involved in tumor cell spread.

Botkjaer, Kenneth A; Deryugina, Elena I

2012-01-01

336

Targeting Tumor Cell Invasion and Dissemination In Vivo by an Aptamer That Inhibits Urokinase-type Plasminogen Activator through a Novel Multifunctional Mechanism  

DEFF Research Database (Denmark)

Data accumulated over the latest two decades have established that the serine protease urokinase-type plasminogen activator (uPA) is a potential therapeutic target in cancer. When designing inhibitors of the proteolytic activity of serine proteases, obtaining sufficient specificity is problematic, because the topology of the proteases' active sites are highly similar. In an effort to generate highly specific uPA inhibitors with new inhibitory modalities, we isolated uPA-binding RNA aptamers by screening a library of 35 nucleotides long 2'-fluoro-pyrimidine RNA molecules using a version of human pro-uPA lacking the epidermal growth factor-like and kringle domains as bait. One pro-uPA-binding aptamer sequence, referred to as upanap-126, proved to be highly specific for human uPA. Upanap-126 delayed the proteolytic conversion of human pro-uPA to active uPA, but did not inhibit plasminogen activation catalyzed by two-chain uPA. The aptamer also inhibited the binding of pro-uPA to uPAR and the binding of vitronectin to the preformed pro-uPA/uPAR complex, both in cell-free systems and on cell surfaces. Furthermore, upanap-126 inhibited human tumor cell invasion in vitro in the Matrigel assay and in vivo in the chick embryo assay of cell escape from microtumors. Finally, upanap-126 significantly reduced the levels of tumor cell intravasation and dissemination in the chick embryo model of spontaneous metastasis. Together, our findings show that usage of upanap-126 represents a novel multifunctional mechanistic modality for inhibition of uPA-dependent processes involved in tumor cell spread.

Botkjaer, Kenneth A; Deryugina, Elena I

2012-01-01

337

In vitro and in vivo antiangiogenic activity of a novel deca-peptide derived from human tissue-type plasminogen activator kringle 2  

Energy Technology Data Exchange (ETDEWEB)

A synthetic deca-peptide corresponding to the amino acid sequence Arg{sup 54}-Trp{sup 63} of human tissue-type plasminogen activator (t-PA) kringle 2 domain, named TKII-10, is produced and tested for its ability to inhibit endothelial cell proliferation, migration, tube formation in vitro, and angiogenesis in vivo. At the same time, another peptide TKII-10S composed of the same 10 amino acids as TKII-10, but in a different sequence, is also produced and tested. The results show that TKII-10 potently inhibits VEGF-stimulated endothelial cell migration and tube formation in a dose-dependent, as well as sequence-dependent, manner in vitro while it is inactive in inhibiting endothelial cell proliferation. Furthermore, TKII-10 potently inhibits angiogenesis in chick chorioallantoic membrane and mouse cornea. The middle four amino acids DGDA in their sequence play an important role in TKII-10 angiogenesis inhibition{sub .} These results suggest that TKII-10 is a novel angiogenesis inhibitor that may serve as a prototype for antiangiogenic drug development.

Su, Li; Xu, Xun; Zhao, Hui; Gu, Qing [Department of Ophthalmology, Shanghai First People' s Hospital, Affiliate of Shanghai Jiaotong University, No. 100 Haining Road, Shanghai 200080 (China); Zou, Haidong, E-mail: zouhaidong@hotmail.com [Department of Ophthalmology, Shanghai First People' s Hospital, Affiliate of Shanghai Jiaotong University, No. 100 Haining Road, Shanghai 200080 (China)

2010-06-11

338

In vitro and in vivo antiangiogenic activity of a novel deca-peptide derived from human tissue-type plasminogen activator kringle 2  

International Nuclear Information System (INIS)

A synthetic deca-peptide corresponding to the amino acid sequence Arg54-Trp63 of human tissue-type plasminogen activator (t-PA) kringle 2 domain, named TKII-10, is produced and tested for its ability to inhibit endothelial cell proliferation, migration, tube formation in vitro, and angiogenesis in vivo. At the same time, another peptide TKII-10S composed of the same 10 amino acids as TKII-10, but in a different sequence, is also produced and tested. The results show that TKII-10 potently inhibits VEGF-stimulated endothelial cell migration and tube formation in a dose-dependent, as well as sequence-dependent, manner in vitro while it is inactive in inhibiting endothelial cell proliferation. Furthermore, TKII-10 potently inhibits angiogenesis in chick chorioallantoic membrane and mouse cornea. The middle four amino acids DGDA in their sequence play an important role in TKII-10 angiogenesis inhibition. These results suggest that TKII-10 is a novel angiogenesis inhibitor that may serve as a prototype for antiangiogenic drug development.

339

Interleukin-1? enhances the aggressive behavior of pancreatic cancer cells by regulating the ?6?1-integrin and urokinase plasminogen activator receptor expression  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In human pancreatic cancer progression, the ?6?1-integrin is expressed on cancer cell surface during invasion and metastasis formation. In this study, we investigated whether interleukin (IL-1? induces the alterations of integrin subunits and urokinase plasminogen activator/urokinase plasminogen activator receptor (uPA/uPAR expression in pancreatic cancer cells. We hypothesize that the alterations of integrin subunits and uPA/uPAR expression make an important role in signaling pathways responsible for biological behavior of pancreatic cancer cells. Results IL-1? upregulated the expression of ?6 and ?1 integrins without any alterations of ?5 and ?v integrins expression. IL-1? also induced enhancement in the expression of uPA/uPAR in pancreatic cancer cells. IL-1? enhanced the proliferation, adhesion, and migration in pancreatic cancer cells, and IL-1?-induced alterations of uPA/uPAR expression correlated with the increased the migration of pancreatic cancer cells. Upregulation of ?6 integrin subunit and uPA/uPAR correlated with the activation of Ras and downstream extracellular signal-regulated kinase (ERK pathways. IL-1?-induced activation of Ras and downstream ERK can be inhibited by using inhibitory antibodies against ?6 and ?1 integrin and uPAR, consistent with the inhibition of proliferation, adhesion and migration of pancreatic cancer cells. Immunohistochemical analysis demonstrated a significant association between strong expressions of ?6 integrin with uPAR in pancreatic cancer specimens. Furthermore, the strong expression of ?6 integrin and uPAR was found to be independent prognosticator in pancreatic cancer patients. Conclusion Based on these findings, we conclude that IL-1? can induce selective upregulation of ?6?1-integrin and uPA/uPAR in pancreatic cancer cells and these changes may modulate the aggressive functions of pancreatic cancer.

Takeyama Hiromitsu

2006-02-01

340

Plasminogen activator inhibitor-2 polymorphism associates with recurrent coronary event risk in patients with high HDL and C-reactive protein levels.  

Science.gov (United States)

The objective of this work was to investigate whether fibrinolysis plays a role in establishing recurrent coronary event risk in a previously identified group of postinfarction patients. This group of patients was defined as having concurrently high levels of high-density lipoprotein cholesterol (HDL-C) and C-reactive protein (CRP) and was previously demonstrated to be at high-risk for recurrent coronary events. Potential risk associations of a genetic polymorphism of plasminogen activator inhibitor-2 (PAI-2) were probed as well as potential modulatory effects on such risk of a polymorphism of low-density lipoprotein receptor related protein (LRP-1), a scavenger receptor known to be involved in fibrinolysis in the context of cellular internalization of plasminogen activator/plansminogen activator inhibitor complexes. To this end, Cox multivariable modeling was performed as a function of genetic polymorphisms of PAI-2 (SERPINB, rs6095) and LRP-1 (LRP1, rs1800156) as well as a set of clinical parameters, blood biomarkers, and genetic polymorphisms previously demonstrated to be significantly and independently associated with risk in the study population including cholesteryl ester transfer protein (CETP, rs708272), p22phox (CYBA, rs4673), and thrombospondin-4 (THBS4, rs1866389). Risk association was demonstrated for the reference allele of the PAI-2 polymorphism (hazard ratio 0.41 per allele, 95% CI 0.20-0.84, p=0.014) along with continued significant risk associations for the p22phox and thrombospondin-4 polymorphisms. Additionally, further analysis revealed interaction of the LRP-1 and PAI-2 polymorphisms in generating differential risk that was illustrated using Kaplan-Meier survival analysis. We conclude from the study that fibrinolysis likely plays a role in establishing recurrent coronary risk in postinfarction patients with concurrently high levels of HDL-C and CRP as manifested by differential effects on risk by polymorphisms of several genes linked to key actions involved in the fibrinolytic process. PMID:23874812

Corsetti, James P; Salzman, Peter; Ryan, Dan; Moss, Arthur J; Zareba, Wojciech; Sparks, Charles E

2013-01-01

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