Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.68 (tissue plasminogen activator)
 11,311 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The susceptibility of native recombinant interferon gamma (rIFN-gamma, Actimmune) and recombinant tissue-type plasminogen activator (rt-PA, Activase) to methionine oxidation when treated with the oxidizing agent t-butyl hydroperoxide (TBHP) was investigated. The results showed that two of the five methionine residues in rIFN-gamma were susceptible to oxidation by TBHP, while three of the five methionines in rt-PA were found to be oxidizable. The oxidized methionine residues were found to be in the sulfoxide [Met(O)] form, and no other residue(s) appeared to be modified during the TBHP treatment. These results also showed that during treatment of a native protein with TBHP only the exposed methionine residues were oxidized. The biological activity of both molecules were unaffected by the treatment with TBHP. A comparative study between TBHP and hydrogen peroxide (H2O2) demonstrated that H2O2 was also a methionine-specific oxidizer. However, this study also showed that H2O2 was not able to distinguish between exposed and buried methionine residues, as significant portions of all five methionine residues in native rIFN-gamma were oxidized by treatment with H2O2. TBHP should be useful for identifying surface methionine residues in a protein of unknown structure and a valuable reagent for methionine oxidation in pharmaceutical stability studies.
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PMID:The use of t-butyl hydroperoxide as a probe for methionine oxidation in proteins. 861 96

This study was undertaken to determine the effects on systemic fibrinolysis of hyperthermic isolated limb perfusion with recombinant tumor necrosis factor alpha (r-TNF-alpha) and melphalan, with or without pretreatment with recombinant IFN-gamma (r-IFN-gamma). Twenty patients were treated with r-TNF-alpha and melphalan; four patients, treated with melphalan only, served as controls. Of the twenty patients treated with both r-TNF-alpha and melphalan, eight received r-IFN-gamma for two days before the perfusion and as a bolus into the perfusion circuit. A significant leak of r-TNF-alpha from the perfusion circuit to the systemic circulation was observed in all r-TNF-alpha-treated patients (mean maximum TNF-alpha, 87,227 ng/liter versus 31 ng/liter in controls; P < 0.002). In these patients, but not in controls, there was an almost instantaneous rise in systemic tissue plasminogen activator activity (from 0.26 to 5.28 IU/ml in 90 min), causing activation of fibrinolysis. After a delay of 90 min, plasminogen activator inhibitor-1 (PAI-1) antigen rose to high levels in the r-TNF-alpha-treated group (mean maximum PAI-1, 1652 ng/ml versus 211 ng/ml in controls; P < 0.02), associated with a sharp decrease of tissue plasminogen activator activity and a slower decrease of plasminogen-antiplasminogen complexes (from 5.28 to 0.02 IU/ml in 2 h and from 1573 to 347 micrograms/liter in 22 h, respectively). No additional effect of IFN-gamma pretreatment on fibrinolysis could be demonstrated. These results suggest that in isolated limb perfusion with r-TNF-alpha and melphalan an initial activation of systemic fibrinolysis, induced by leakage of r-TNF-alpha from the perfusion circuit, is set off by a subsequent inhibition of the fibrinolytic system by PAI-1. This large increase in PAI-1 could place the patient at risk for deposition of microthrombi in the systemic circulation.
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PMID:Effects of hyperthermic isolated limb perfusion with recombinant tumor necrosis factor alpha and melphalan on the human fibrinolytic system. 875 62

Dengue virus infection causes dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS), whose pathogeneses are not clearly understood. Current hypotheses of antibody-dependent enhancement, virus virulence, and IFN-gamma/TNFalpha-mediated immunopathogenesis are insufficient to explain clinical manifestations of DHF/DSS such as thrombocytopenia and hemoconcentration. Dengue virus infection induces transient immune aberrant activation of CD4/CD8 ratio inversion and cytokine overproduction, and infection of endothelial cells and hepatocytes causes apoptosis and dysfunction of these cells. The coagulation and fibrinolysis systems are also activated after dengue virus infection. We propose a new hypothesis for the immunopathogenesis for dengue virus infection. The aberrant immune responses not only impair the immune response to clear the virus, but also result in overproduction of cytokines that affect monocytes, endothelial cells, and hepatocytes. Platelets are destroyed by crossreactive anti-platelet autoantibodies. Dengue-virus-induced vasculopathy and coagulopathy must be involved in the pathogenesis of hemorrhage, and the unbalance between coagulation and fibrinolysis activation increases the likelihood of severe hemorrhage in DHF/DSS. Hemostasis is maintained unless the dysregulation of coagulation and fibrinolysis persists. The overproduced IL-6 might play a crucial role in the enhanced production of anti-platelet or anti-endothelial cell autoantibodies, elevated levels of tPA, as well as a deficiency in coagulation. Capillary leakage is triggered by the dengue virus itself or by antibodies to its antigens. This immunopathogenesis of DHF/DSS can account for specific characteristics of clinical, pathologic, and epidemiological observations in dengue virus infection.
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PMID:Immunopathogenesis of dengue virus infection. 1154 79

The immunogenicity and protective efficacy of a DNA vaccine encoding the GroEL heat-shock gene from Brucella abortus was tested in BALB/c mice immunised by intramuscular (i.m.) needle injection or epidermally by gene gun. The Brucella GroEL gene was amplified by PCR and cloned into two different mammalian expression vectors pCMV-link and pCMV-tPA. The D17 cell line was transfected with both constructs and GroEL transcripts were detected by Northern blot. To determine the level of protein synthesised, transfected cell lysates were then submitted to Western blot. The non-secreted form of the recombinant GroEL produced by the pCMV-link construct was detected in much greater amount than the secreted form of the protein produced by the pCMV-tPA construct. After immunisation, a strong anti-GroEL IgG response was detected in mice vaccinated by i.m. injection or gene gun only when the pCMV-link/ GroEL plasmid was used. Regarding the pattern of immune response induced, i.m. needle injection raised a predominantly Th1 response with mostly IgG2a-specific anti-GroEL and high levels of IFN-gamma produced by splenic T cells. Gene gun immunisation induced a ThO type of immune response in mice characterised by a high IgG1/IgG2a ratio, and IL-4 and interferon (IFN)-gamma production. Even though a distinct pattern of immune response was generated depending upon the immunisation route used, neither method engendered a significant level of protection with the GroEL DNA vaccine.
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PMID:Induction of a th1-type of immune response but not protective immunity by intramuscular DNA immunisation with Brucella abortus GroEL heat-shock gene. 1180 49

Cytokines and growth factors that influence both secretion of the extracellular matrix (ECM) proteins and migration of the cells decide about the final outcome of tissue remodelling. We have examined expression of the components of the plasminogen activation system in human astrocytoma U373-MG cells and found that interleukin 1beta (IL-1beta), tumour necrosis factor alpha TNF-alpha), interferon gamma (INF-gamma) and epidermal growth factor (EGF) specifically regulate the expression of tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitor type 1 (PAI-1) and protease nexin-1 (PN-1). We conclude that EGF and IFN-gamma are new important regulators of the plasminogen activation system in astrocytoma cells and, therefore, may influence turnover of extracellular matrix and migration of cells within the brain.
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PMID:Epidermal growth factor and pro-inflammatory cytokines regulate the expression of components of plasminogen activation system in U373-MG astrocytoma cells. 1181 14

A substantial literature demonstrates activation of inflammatory processes in the Alzheimer's disease (AD) brain and an association between inflammation and oxidative stress. We have shown that brain microvessels from AD patients express high levels of inflammatory proteins and that these proteins evoke release of the neurotoxic protease thrombin from brain endothelial cells. The objective of this study was to determine the effects of inflammatory proteins on brain endothelial cell reactive oxygen species generation, protease release and cell apoptosis. Also, the effects of inflammatory proteins on neuronal reactive oxygen species generation, injury and apoptosis were assessed. Treatment of cultured brain endothelial cells with inflammatory proteins (LPS, IL-1beta, IL-6, IFN-gamma, TNF-alpha) resulted in a significant increase (p < 0.01) in intracellular levels of reactive oxygen species by 1 h. Inflammatory proteins also caused release of tissue plasminogen activator and increased apoptosis by 24 h in these cells. In cultured neurons, inflammatory proteins caused an increase in reactive oxygen species, membrane fluidity, and apoptosis by 24 h, as detected by fluorescent microscopy. Taken together, these data support the hypothesis that vascular inflammatory, oxidative and protease-based processes contribute to neuronal cell death, and suggest that therapies targeted at these mediators and processes could be effective in AD.
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PMID:Vascular inflammatory, oxidative and protease-based processes: implications for neuronal cell death in Alzheimer's disease. 1526 71

Plasminogen activator inhibitor type-1 (PAI-1) is a major inhibitor of fibrinolysis by virtue of its capacity to inhibit urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Systemic inflammation is invariably associated with elevated circulating levels of PAI-1, and during human sepsis plasma PAI-1 concentrations predict an unfavorable outcome. Knowledge about the functional role of PAI-1 in a systemic inflammatory response syndrome is highly limited. In this study, we determined the role of endogenous PAI-1 in cytokine release induced by administration of LPS or staphylococcal enterotoxin B (SEB). Both LPS and SEB elicited secretion of PAI-1 into the circulation of normal wild-type (Wt) mice. Relative to Wt mice, PAI-1 gene-deficient (PAI-1(-/-)) mice demonstrated strongly elevated plasma IFN-gamma concentrations after injection of either LPS or SEB. In addition, PAI-1(-/-) splenocytes released more IFN-gamma after incubation with LPS or SEB than Wt splenocytes. Both PAI-1(-/-) CD4+ and CD8+ T cells produced more IFN-gamma upon stimulation with SEB. LPS-induced IFN-gamma release in mice deficient for uPA, the uPA receptor, or tPA was not different from IFN-gamma release in LPS-treated Wt mice. These results identify a novel function of PAI-1 during systemic inflammation, where endogenous PAI-1 serves to inhibit IFN-gamma release by a mechanism that does not depend on its interaction with uPA/uPA receptor or tPA.
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PMID:Plasminogen activator inhibitor type-1-deficient mice have an enhanced IFN-gamma response to lipopolysaccharide and staphylococcal enterotoxin B. 1711 93

Squamous cell carcinoma of the head and neck (SCCHN) is an aggressive disease that has been linked to altered immune, inflammatory, and angiogenesis responses. A better understanding of these aberrant responses might improve early detection and prognosis of SCCHN and provide novel therapeutic targets. Previous studies examined the role of multiplexed serum biomarkers in small cohorts or SCCHN sera. We hypothesized that an expanded panel comprised of multiple cytokines, chemokines, growth factors, and other tumor markers, which individually may show some promising correlation with disease status, might provide higher diagnostic power if used in combination. Thus, we evaluated a novel multianalyte LabMAP profiling technology that allows simultaneous measurement of multiple serum biomarkers. Concentrations of 60 cytokines, growth factors, and tumor antigens were measured in the sera of 116 SCCHN patients before treatment (active disease group), 103 patients who were successfully treated (no evidence of disease group), and 117 smoker controls without evidence of cancer. The multimarker panel offering the highest diagnostic power was comprised of 25 biomarkers, including epidermal growth factor, epidermal growth factor receptor, interleukin (IL)-8, tissue plasminogen activator inhibitor-1, alpha-fetoprotein, matrix metalloproteinase-2, matrix metalloproteinase-3, IFN-alpha, IFN-gamma, IFN-inducible protein-10, regulated on activation, normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein-1alpha, IL-7, IL-17, IL-1 receptor-alpha, IL-2 receptor, granulocyte colony-stimulating factor, mesothelin, insulin-like growth factor binding protein 1, E-selectin, cytokeratin-19, vascular cell adhesion molecule, and cancer antigen-125. Statistical analysis using an ADE algorithm resulted in a sensitivity of 84.5%, specificity of 98%, and 92% of patients in the active disease group correctly classified from a cross-validation serum set. The data presented show that simultaneous testing using a multiplexed panel of serum biomarkers may present a promising new approach for the early detection of head and neck cancer.
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PMID:Early detection of head and neck cancer: development of a novel screening tool using multiplexed immunobead-based biomarker profiling. 1722 Mar 37

Plasminogen activators are used in thrombolytic stroke therapy. However, it is increasingly recognized that they have other actions besides fibrinolysis. In this study, we assess potential pro-inflammatory effects of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) in rat cortical astrocytes. Both uPA and tPA induced rapid dose-dependent upregulation in MMP-2 and MMP-9, as demonstrated by zymography of conditioned media. In addition, a multiplex ELISA array demonstrated that patterned responses in chemokines and cytokines were also evoked. Exposure to tPA induced elevations in secreted MIP-2, MCP-1 and GRO/KC. Exposure to uPA induced elevations in secreted IFN-gamma, TNF-alpha, GMCSF, MIP-1alpha, MIP-2, MIP-3alpha, MCP-1, RANTES and fractalkine. These data suggest that plasminogen activators may trigger selected pro-inflammatory responses at the neurovascular interface. Whether these effects influence thrombolytic stroke therapy warrants further investigation.
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PMID:Induction of matrix metalloproteinase, cytokines and chemokines in rat cortical astrocytes exposed to plasminogen activators. 1738 75

In the current study, immune responses induced by Gag DNA vaccines with different designs were evaluated in Balb/C mice. The results demonstrated that the DNA vaccine with the full length wild type gag gene (Wt-Gag) mainly produced Gag antigens intracellularly and induced a higher level of cell-mediated immune (CMI) responses, as measured by IFN-gamma ELISPOT, intracellular cytokine staining (ICS), and cytotoxic T lymphocytes (CTL) assays against a dominant CD8(+) T cell epitope (AMQMLKETI). In contrast, the addition of a tissue plasminogen activator (tPA) leader sequence significantly improved overall Gag protein expression/secretion and Gag-specific antibody responses; however, Gag-specific CMI responses were decreased. The mutation of zinc-finger motif changed Gag protein expression patterns and reduced the ability to generate both CMI and antibody responses against Gag. These findings indicate that the structure and post-translational processing of antigens expressed by DNA vaccines play a critical role in eliciting optimal antibody or CMI responses.
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PMID:Post-translational intracellular trafficking determines the type of immune response elicited by DNA vaccines expressing Gag antigen of Human Immunodeficiency Virus Type 1 (HIV-1). 2394 68


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