Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.5 (thrombin)
33,306 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human blood monocytes (Mo) and monocyte-derived macrophages (M psi) possess cytotoxic effects against tumor cell lines when appropriately stimulated by various biological response modifiers, e.g., gamma interferon (gamma IFN) and muramyltripeptide (MTP). Activated Mo/M psi represent a new tool for the treatment of human malignancies, termed "adoptive cellular immunotherapy". Activated Mo/M psi express tissue factor procoagulant activity (PCA), which is a physiological trigger of blood coagulation. PCA was evaluated in vitro using a modification of the one-stage recalcification clotting time, and hemostatic changes were studied in vivo in cancer patients. Nine patients with peritoneal carcinomatosis were injected intraperitoneally with activated Mo and 11 patients with non-small cell lung carcinomas were infused intravenously with activated M psi. Hemostatic changes were followed using activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen level, antithrombin III (ATIII) and protein C (PC) activities. Fibrinolytic activity was estimated by euglobulin lysis time and assays for plasminogen and fibrin/fibrinogen degradation products (FDP). These assays were performed before and after each autologous infusion and on days 2 and 3. Activated Mo and M psi expressed potent PCA (85.5 +/- 7.5 U/ml for MTP activated Mo and 50 +/- 5.3 U/ml for gamma IFN activated M psi suspensions). In both groups of patients, APTT, PT, and TT underwent no significant variations. There was no significant consumption of ATIII or PC, and fibrinolysis was not activated during the study period. In the group injected intraperitoneally with MTP-activated Mo, fibrinogen showed a significant and progressive increase in relation to the development of an inflammatory reaction, reaching a maximum average value of 6.1 g/l at the end of the therapy with a concomitant increase in FDP levels. This increase was not observed after intravenous therapy with gamma IFN-activated M psi. No patient suffered from hemorrhagic or thrombotic events. In our experience, repeated injections of activated Mo or M psi expressing potent tissue factor PCA did not induce significant in vivo activation of the coagulation system in cancer patients.
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PMID:Hemostatic changes in human adoptive immunotherapy with activated blood monocytes or derived macrophages. 132 42

Cells of the macrophage lineage are considered to be of special importance in the defense of the host against tumor development and spread. Immunotherapeutic strategies to stimulate macrophage (MAC) tumor cytotoxicity make use of activating compounds such as gamma-interferon which are given systemically. However, there are several lines of evidence that in malignant disease the generation of cytotoxic effector MACs is impaired. Both defective cell maturation and loss of responsiveness to activation are described. Here, a first clinical phase I trial of adoptive immunotherapy in cancer patients using autologous MACs generated in vitro from blood monocytes (MOs) is reported. Mononuclear cells were isolated by cytapheresis and density centrifugation and cultured in hydrophobic Teflon bags for 7 days with 2% autologous serum and recombinant human gamma-interferon being present for the last 18 h. Cytotoxic MO-derived MACs were then purified by countercurrent elutriation and reinfused into the patient. A total of 72 therapies have been performed with patients being treated i.v. (n = 8) and i.p. (n = 7). In vitro generated MACs proved to be mature as judged by the expression of maturation-associated surface molecules (MAX antigens, CD16, CD51, CD71), were cytotoxic to U937 tumor cells, and were efficient secretory cells. Cell dose escalation was performed in the first patients beginning with 10(8) MACs to finally infuse the total number of cells recovered from one single cycle of isolation and culture. MAC yield varied from 1 to 17 x 10(8) representing 13-79% of MOs initially seeded. Adoptive MAc transfer was well tolerated. Side effects observed were low-grade fever (less than 38.5 degrees C), induction of the coagulation cascade, and abdominal discomfort after i.p. application. The procoagulant activity of MAC autografts was cell dose dependent and demonstrated by detection of circulating fibrin monomers and thrombin-antithrombin complexes. Biological responses observed included elevated serum neopterin levels and the appearance of interleukin-6 in sera and ascitic fluids. Indication of a possible therapeutic effect was only observed in i.p.-treated patients and consisted of disappearance of malignant ascites in 2 of 7 patients.
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PMID:Adoptive transfer of tumor cytotoxic macrophages generated in vitro from circulating blood monocytes: a new approach to cancer immunotherapy. 170 43

The effects of thrombin, interleukin-1 (IL-1), tumor necrosis factor (TNF) and gamma-interferon (gamma-IFN) on the release of plasminogen activator (PA) and inhibitor (PAI) were studied using cultivated human glomerular epithelial cells (GECs). Species of PAs and PAI secreted from the GECs were urokinase-type PA (u-PA) and tissue-type PA (t-PA), while the major species was a single chain u-PA in the amount of 28.6 +/- 2.34 ng/10(5) cells for 24 hours (N = 4, mean +/- SD), and PAI-1. The addition of increased concentrations of thrombin (0.1 to 31.6 U/ml) into confluent cultures enhanced the GECs to release u-PA, t-PA and PAI-1 in a dose- and time-dependent manner. The incubation of the GECs with 10 U/ml thrombin resulted in about a fourfold increase in the concentration of u-PA, threefold in t-PA and twofold in PAI-1. All thrombin effects, however, were suppressed by the simultaneous addition of cycloheximide, indicating that the enhancing effects of thrombin were due to an increase in the production of PAs and PAI-1, via protein synthesis. These thrombin effects appeared to be dependent upon the enzymatically active site of thrombin because DFP-thrombin had no effect. In the conditioned medium which was under continuous thrombin stimulation for 24 hours, no u-PA activity was detectable, even after the plasmin treatment, because a single chain u-PA was degraded by the thrombin. The stimulation of cultured GECs with thrombin only for the first three hours in 24 hour cultivation showed an apparent increase in the antigenic amount of u-PA. IL-1 enhanced the release of t-PA and PAI-1, and TNF did that of u-PA and t-PA, while gamma-IFN showed no significant effects. These findings indicate that the GECs participate in the regulation of extracapillary fibrinolysis in the glomerular microenvironment, as being modulated by thrombin and two cytokines, IL-1 and TNF.
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PMID:Secretion of plasminogen activator and its inhibitor by glomerular epithelial cells. 211 68

The human alveolar macrophage product, enzyme-releasing peptide (ERP), has a molecular mass of 8,000 Da, and releases azurophilic and specific granule constituents from neutrophils. A murine monoclonal anti-ERP antibody (12E10H), previously used to show a lack of antigenic identity between ERP and C5a, interleukin 1, tumor necrosis factor, and gamma-interferon, showed no cross-reactivity with interleukin 8. 12E10H and a fluorescein-labeled second antibody were used to visualize ERP on the macrophage surface. ERP was removed from alveolar macrophages by a 3-min incubation with 5 X 10(-7) M bovine pancreatic trypsin at 37 degrees C. The washed trypsinized cells could readhere to plastic and exclude trypan blue. Dilution of the trypsin-derived ERP released myeloperoxidase from cytochalasin-B-treated neutrophils dose dependently. The enzyme-releasing ability of the trypsin-derived material was removed by immunoprecipitation using antibody 12E10H bound to Staphylococcal protein A Sepharose 4B. The estimated molecular mass of the trypsin-derived ERP (by molecular sieve chromatography on HPLC) was approximately 8,500 Da. Other proteases (plasmin, thrombin, and cathepsin G) also released ERP from the cell surface, but the ERP was not an active secretagogue for neutrophils. However, macrophages cultured with protease inhibitors did not show decreased ERP accumulation in the medium. Our data indicate that ERP exists on the surface of human alveolar macrophages and can be released by proteases found within the lung environment in some disease states.
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PMID:Liberation of a neutrophil enzyme-releasing peptide from the surface of human alveolar macrophages. 236 Jun 46

A plasminogen activator inhibitor was purified to apparent homogeneity from conditioned media of U138 cells. The inhibitor is a glycoprotein with a pI of 5.4 and an apparent molecular weight of 45,000. The inhibitor forms sodium dodecyl sulfate-stable complexes with plasminogen activators and trypsin but not with plasmin, thrombin, or pancreatic kallikrein. Some biochemical and immunochemical characteristics of the U138 inhibitor distinguish it from other known plasminogen activator inhibitors. The expression of this inhibitor by U138 cells could be modulated by incubation in phorbol myristate acetate, interleukin-1, tumor necrosis factor, and gamma interferon, but not in beta interferon. Thus, the expression of the plasminogen activator inhibitor can be influenced by biological response modifiers known to be active in the brain and in the neural response to inflammatory stimuli. Therefore, this inhibitor, along with protease nexin, may be involved in brain development and regulation.
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PMID:Purification and partial characterization of a plasminogen activator inhibitor from the human glioblastoma, U138. 314 98

Peritoneal cells from thioglycollate-stimulated mice were allowed to adhere to coverglasses for 2 h to give a dense monolayer of adherent cells greater than 95% of which were macrophages. After incubation with the tetra-acetoxymethyl ester of quin2, coverglasses were rinsed with Ca2+-free saline, oriented at a 45 degree angle in square cuvettes containing a magnetically driven stir bar, and analyzed for changes in quin2 fluorescence in a spectrofluorimeter. Such fluorescence, taken as an indication of intracellular calcium ion concentration ([Ca2+]i), increased as exogenous calcium ion concentration ([Ca2+]o) was raised to 1 mM. At [Ca2+]o approximately equal to 10 microM, [Ca2+]i = 72 +/- 14 nM (n = 26); at [Ca2+]o = 1 mM, [Ca2+]i = 140-220 nM, levels not increased by N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine, a membrane-permeant chelator of heavy metals than can quench quin2. Addition of mouse alpha + beta fibroblast interferon, lipopolysaccharide, thrombin, collagen, vasopressin, ADP, compound 48/80, or U46619 did not change [Ca2+]i. However, addition of platelet activating factor (PAF) (2-20 ng/ml) raised [Ca2+]i by 480 nM within 1 min if [Ca2+]o = 1 mM. In the presence of 5 mM EGTA, PAF raised [Ca2+]i by 25 nM. This suggests that PAF causes influx of exogenous Ca2+, as well as releasing some Ca2+ from intracellular stores. Consistent with these results, when PAF was added to 1 mM Ca2+ in the presence of 100 microM Cd2+ or Mn2+ to block Ca2+ influx, [Ca2+]i increased by only intermediate amounts; at the times of such dampened peak response, [Ca2+]i could be raised within 1 min to normal PAF-stimulated levels by chelation of the exogenous heavy metals with diethylenetriaminepentaacetic acid. Normal PAF responses were observed in the presence of indomethacin. The lowest dose of PAF observed to raise [Ca2+]i was 0.1 ng/ml. Response of [Ca2+]i to 2-20 ng/ml PAF was transient, and second applications had no effect. The PAF response also was seen in cell suspensions. These results suggest that an increase in [Ca2+]i may be an early event in PAF activation of macrophages.
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PMID:Platelet activating factor raises intracellular calcium ion concentration in macrophages. 373 74

A role of gamma-interferon in the bone remodeling process can be implicated from its interference with bone resorptive processes in cultured neonatal mouse calvaria. The immune interferon is an efficient inhibitor of endogenous prostaglandin synthesis, particularly after stimulation by thrombin or arachidonic acid, and, in addition, has a calcitonin-like inhibitory effect on PTH-induced osteoclastic bone resorption.
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PMID:Recombinant gamma-interferon inhibits prostaglandin-mediated and parathyroid hormone-induced bone resorption in cultured neonatal mouse calvaria. 392 96

Treatment of patients with interferon or inducers of interferon results in an enhanced level of a protein kinase activity found in platelets (1,3). The kinase activity is responsible for the phosphorylation of a 70-72,000 molecular weight protein (72K protein) found in blood plasma. By the means of a technique based on the precipitation of this protein kinase system (the protein kinase and its substrate), we show here that the 72K protein is the alpha-chain of fibrinogen. During the coagulation process induced by thrombin, the 32P-labelled 72K protein is recovered in the clot. After incubation in the presence of thrombin, the 72K protein looses a small polypeptide of 2-3000 in molecular weight resulting a shift in its isoelectric point (pI) from 6.8-7.0 to 7.5. At the end of the coagulation process, the 32P-labelled 72K protein becomes undetectable since it gives rise to a covalently linked alpha-polymer of a high molecular weight. In accord with these results, the 72K protein could be precipitated by antibodies against human fibrinogen.
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PMID:Phosphorylation of the alpha-chain of fibrinogen by a platelet kinase activity enhanced by interferon. 619 71

Interferon-treated mouse and human cells show enhanced levels of a protein kinase activity which is manifested by the phosphorylation of endogenous Mr = 67,000 and 72,000 proteins, respectively. Such kinase activity can be assayed after its partial purification on poly(I) X poly(C)-Sepharose. Under these experimental conditions, the apparent km of the kinase for ATP is 1.0 X 10(-6) M and 2.5 X 10(-6) M in enzyme fractions from mouse L-929 and human HeLa cells, respectively. The Mr = 67,000 and 72,000 proteins are phosphorylated by their serine and threonine residues, the ratio of which is modified in preparations from interferon-treated cells. Both of these phosphoproteins are composed of several subspecies with similar isoelectric points (pIs) in the range of 7.2 to 8.2. This heterogeneity is due to the number of phosphate groups per molecule of protein. Accordingly, the pIs of highly phosphorylated proteins are at a less basic pH (7.2 to 7.5). Furthermore, highly phosphorylated proteins show an increase in their apparent molecular weights compared to partially phosphorylated ones. This corresponds to an increase of Mr = 1,500. Partial proteolysis of the 32P-labeled Mr = 67,000 and 72,000 proteins by Staphylococcus aureus V8 protease, alpha-chymotrypsin and thrombin, indicated that these phosphoproteins differ in their polypeptide structure. Phosphorylation of the Mr = 67,000 and 72,000 proteins in enzyme fractions from control L-929 and HeLa cells is enhanced by mixing with extracts from interferon-treated heterologous cells. Proteins, Mr = 67,000 and 72,000, therefore, may serve as suitable substrates for an exogenous kinase, thus indicating that the substrate in enzyme fractions from control cells is less phosphorylated because of a low level of kinase activity.
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PMID:Further characterization of the protein kinase activity mediated by interferon in mouse and human cells. 620 11

Inflammation-induced localized bone resorption in diseases such as marginal and apical periodontitis, rheumatoid arthritis, and osteomyelitis is due to activation and recruitment of osteoclasts by locally produced cytokines and inflammatory mediators. Thus several interleukins (1, 3, 4, 6, and 11), tumor necrosis factors (alpha, beta), colony-stimulating factors (M and GM), leukemia inhibitory factor, gamma-interferon, and transforming growth factor-beta have effects on bone resorption and bone formation in vivo and in vitro. The kallikrein-kinin system and the coagulation cascade are also activated in inflammation. We have found that peptides produced in the kallikrein-kinin system (bradykinin, kallidin) and thrombin, the end product in the coagulation cascade, can stimulate bone resorption in vitro. The stimulatory effect of bradykinin is linked both to B1 and B2 bradykinin receptors. Both kinins and thrombin stimulate prostaglandin biosynthesis in bone parallel with the bone resorptive effect. The stimulatory effect of bradykinin on bone resorption is completely lost when the prostaglandin response is abolished, whereas thrombin can stimulate bone resorption both via prostaglandin-dependent and independent mechanisms. In addition, bradykinin and thrombin act in concert with interleukin-1 to synergistically stimulate bone resorption and prostaglandin biosynthesis. We also have found that one of the acute-phase reactants, haptoglobin, can stimulate bone resorption in vitro, indicating the possibility of generalized bone loss in chronic inflammatory diseases. Moreover, haptoglobin synergistically potentiates bradykinin-induced and thrombin-induced prostanoid biosynthesis in osteoblasts. These observations indicate that the rate of bone resorption in inflammation-induced bone loss may not be due to a single factor but to the concerted action of several local or systemic factors.
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PMID:Regulation of bone metabolism by the kallikrein-kinin system, the coagulation cascade, and the acute-phase reactants. 752 72


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