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W Kisiel

Publications and source records attributed to W Kisiel.

At least 127 records · Page 7Linked to original sources

Correlation between antigenic and functional expression of tissue factor on the surface of cultured human endothelial cells following stimulation by lipopolysaccharide endotoxin.

Previous studies indicated that E. coli lipopolysaccharide (LPS) induces human umbilical vein endothelial cells (HUVEC) to express tissue factor activity. Using a radiolabeled anti-tissue factor monoclonal antibody to assess cell-surface tissue factor apoprotein antigen and a two-stage amidolytic assay to assess functional tissue factor activity, we have investigated the temporal relationship between antigenic expression and functional expression of tissue factor on the surface of LPS-stimulated HUVEC. Maximum tissue factor apoprotein antigenic expression on the surface of LPS-stimulated HUVEC was achieved in four hours after LPS treatment, while maximum functional tissue factor activity occurred after 6 hours. Specific binding of radiolabelled human factor VIIa to LPS-stimulated HUVEC paralleled the time course of the expression of tissue factor functional activity. Thus, these data indicate that the presence of of newly-synthesized tissue factor apoprotein antigen on the cell surface is insufficient by itself for maximal factor VIIa binding to occur, and provide presumptive evidence for the posttranslational processing of tissue factor apoprotein on the cell surface prior to its acquisition of ligand binding function.

Antibody Formation↗

Binding of human factors VII and VIIa to a human bladder carcinoma cell line (J82). Implications for the initiation of the extrinsic pathway of blood coagulation.

We have studied the binding of radioiodinated human factor VII and its activated form, factor VIIa, to monolayers of a human bladder carcinoma cell line (J82) that expresses functional cell surface tissue factor. The binding of factors VII and VIIa to these cells was found to be time-, temperature-, and calcium-dependent. In addition, the binding of each protein to J82 cells was specific, dose-dependent, and saturable. The binding isotherms for factors VII and VIIa were hyperbolic, and Scatchard plots of the binding data obtained at 37 degrees C indicated a single class of binding sites for each protein with Kd values of 3.20 +/- 0.51 and 3.25 +/- 0.31 nM, respectively. Factors VII and VIIa, respectively, interacted with 256,000 +/- 39,000 and 320,000 +/- 31,000 binding sites/cell. Competition experiments suggested a common receptor for factors VII and VIIa. Binding of factor VIIa to the cells was completely blocked by preincubation of the cells with polyclonal anti-tissue factor IgG, whereas binding of factor VII was inhibited approximately 90%, suggesting the presence of a small number of tissue factor-independent binding sites specific for factor VII on this cell. Functional studies revealed that factor X activation by increasing amounts of cell-bound factor VII or VIIa was hyperbolic in nature. Half-maximal rates of factor Xa formation occurred at factor VII and VIIa concentrations of 3.7 +/- 0.47 and 3.2 +/- 0.31 nM, respectively. No factor VII- or VIIa-mediated activation of factor X was observed when cells were preincubated with anti-tissue factor IgG. Two-chain 125I-factor VIIa recovered from the cells was identical to the offered ligand as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. In contrast, the offered single-chain 125I-factor VII was progressively converted to two-chain 125I-factor VIIa upon binding to the cells. When the J82 cells were pretreated with anti-tissue factor IgG, both factor VII recovered from the cells and factor VII in the supernatant were in the single-chain form, indicating that cell-surface tissue factor was essential for the activation of factor VII on these cells. These data indicate that binding of factor VII to tissue factor appears to be a prerequisite for its conversion to factor VIIa and the initiation of the extrinsic pathway of coagulation on these cells.

Binding, Competitive↗

Activation of human factor VII by factors IXa and Xa on human bladder carcinoma cells.

Single chain factor VII is converted by limited proteolysis to its activated form, factor VIIa, by a number of blood coagulation proteases including factor IXa and factor Xa. We have determined the relative rate of human factor VII activation by human factors IXa and Xa in two different systems: one containing Ca++ and human bladder carcinoma (J82) cells, and the other containing Ca++ and mixed brain phospholipids. The rate of factor VII activation was determined by a one stage coagulation assay, and proteolytic cleavage of factor VII was assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting techniques. On a molar basis, factor Xa was sixfold more efficient than factor IXa beta in activating factor VII when the activation reaction occurs on J82 cell surfaces. In contrast, when incubation takes place in a suspension of mixed phospholipids, factor Xa was 18-fold more efficient in activating factor VII than factor IXa beta. In addition, factor IXa alpha activated factor VII at a rate approximately one-half that observed using factor IXa beta. In the absence of cells or phospholipids, no activation of factor VII by either factors IXa or Xa was observed. The addition of stoichiometric amounts of either recombinant human factor VIII (des B-domain) or plasma-derived factor VIIIa failed to augment the rate of factor VII activation by either factors IXa alpha or IXa beta. Likewise, purified human factor Va failed to influence the rate of factor VII activation by factor Xa in either system. Collectively, our studies reveal that J82 cells possess procoagulant phospholipid capable of readily supporting the activation of factor VII by either factors IXa beta or Xa. Our data also demonstrate that the relative ability of factor IXa beta and Xa to activate factor VII is significantly different when these reactions occur on tumor cell surfaces as compared with suspensions of mixed phospholipids.

Blood Coagulation Tests↗

Identification and partial purification of a novel tumor-derived protein that induces tissue factor on cultured human endothelial cells.

Conditioned medium of a human bladder carcinoma cell line (J82) was found to induce tissue factor synthesis in cultured human umbilical vein endothelial cells (HUVEC). A protein present in the J82 conditioned medium was partially purified by FPLC using a combination of MONO Q and Superose 6 columns. The bladder carcinoma-derived cytokine (BCDC) exhibited a Mr of 22 kDa by gel permeation HPLC. Polyclonal antibody against either interleukin-1, tumor necrosis factor, or transforming growth factor-beta failed to inhibit the ability of the conditioned medium to induce HUVEC tissue factor activity, suggesting that this tumor cell line secretes a novel cytokine responsible for HUVEC tissue factor induction.

Biological Factors↗

Primary structure of a protein C activator from Agkistrodon contortrix contortrix venom.

The amino acid sequence of a protease, protein C activator, from Agkistrodon contortrix contortrix venom was determined. Peptide fragments obtained by chemical or enzymatic cleavage of the S-carboxymethylated protein were purified by gel filtration and reverse-phase high-performance liquid chromatography. The present study demonstrates that protein C activator from A. contortrix contortrix venom is a trypsin-type serine protease that is composed of 231 residues with a molecular weight of 25,095 for the polypeptide portion of the molecule. By analogy to the mammalian serine proteases, the catalytic triad in venom protein C activator consists of His-40, Asp-85, and Ser-177. The protein also contains three N-linked glycosylation sites at Asn-21, Asn-78, and Asn-129. The amino acid sequence of protein C activator exhibits a high degree of sequence identity with other snake venom proteases: 73% with batroxobin, 68% with flavoxobin, and 55% with Russell's viper venom factor V activator.

Amino Acid Sequence↗

The factor V-activating enzyme (RVV-V) from Russell's viper venom. Identification of isoproteins RVV-V alpha, -V beta, and -V gamma and their complete amino acid sequences.

The complete amino acid sequences of two isoproteins of the factor V-activating enzyme (RVV-V) isolated from Vipera russelli (Russell's viper) venom were determined by sequencing S-pyridylethylated derivatives of the proteins and their peptide fragments generated by either chemical (cyanogen bromide and 2-(2-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine) or enzymatic (trypsin, alpha-chymotrypsin, and lysyl endopeptidase) cleavages. Both enzymes, designated RVV-V alpha and RVV-V gamma, consist of 236 amino acid residues and have a N-linked oligosaccharide chain at Asn229. The six amino acid substitutions between RVV-V alpha and -V gamma are: Thr22(alpha)-Ala22(gamma), Gly29(alpha)-Ala29(gamma), Gln191(alpha)-Glu191(gamma), Ile192(alpha)-Met192(gamma), Gln193(alpha)-His193(gamma), and Asn224(alpha)-Ser224(gamma). The molecular weights were calculated as 26,182 for RVV-V alpha and 26,167 for RVV-V gamma. The sequences of the RVV-V isoproteins exhibited 62% identity with that of batroxobin, a thrombin-like enzyme present in Bothrops atrox venom, and 33% identity with that of human thrombin B chain. The most interesting difference between the structures of RVV-V and other trypsin-type serine proteases is that the conservative Ser214-Trp215-Gly216 sequence (chymotrypsinogen numbering), considered as the site of antiparallel beta-sheet formation between the protein substrate and most serine proteases, has been replaced by the corresponding sequence Ala-Gly-Gly.

Amino Acid Sequence↗

Inhibition of prothrombin activation by factor X and factor IX Gla-peptides.

In the present study, human factor X and factor IX were each digested with chymotrypsin, and the Gla-peptide from each protein was purified by QAE-Sephadex chromatography. The effect of each Gla-peptide on the activation of human prothrombin by a complex of factor Xa, phospholipid, and calcium was studied using an amidolytic assay for generated thrombin. Prothrombin activation was half-maximally inhibited by factor X Gla-peptide at a concentration of 0.7 microM. Factor IX Gla-peptide was markedly less inhibitory and inhibited this reaction half-maximally at a concentration of 3.7 microM. Kinetic analyses revealed that the factor X Gla-peptide inhibited this reaction in an apparent competitive manner, whereas the factor IX Gla-peptide yielded an exponential Dixon plot. Heat decarboxylation experiments revealed that 3-4 gamma-carboxyglutamic acid residues are critical for the expression of inhibitory activity in each peptide. These studies indicate that, in spite of their structural homology, the ability of each of these Gla-peptides to act as a prothrombinase inhibitor is markedly different.

Factor IX↗

Atherosclerosis and coronary bypass surgery in hereditary factor VII deficiency.

A 66-year-old man with homozygous deficiency of factor VII (less activity than 4 percent of normal) had a minimal hemorrhagic tendency and severe coronary atherosclerosis, and underwent aortocoronary saphenous vein bypass surgery. Although plasma factor VII coagulant activity and cross-reacting material were markedly reduced, comparable amounts of factor VII antigen were detected in peripheral blood mononuclear cells of both the patient and of a normal subject by Western blotting techniques. Accelerated coagulation was observed following brief exposure of the patient's phytohemagglutinin-stimulated peripheral blood mononuclear cells to low concentrations of ambient factor VII in vitro. Evidence indicates that factor VII plays a role in vivo in both hemostasis and atherogenesis and it might be assumed that factor VII deficiency would both predispose to excessive bleeding and forestall atherosclerosis. However, these observations suggest that factor VII-mediated thrombin generation may proceed by partitioning of small amounts of factor VII on tissue factor-expressing cells and that factor VII contained within monocytes may facilitate tissue factor-induced coagulation by these cells. These features may provide efficient coagulation activation despite a deficiency of the plasma coagulant protein. The current results may explain, at least in part, the minimal bleeding tendency, and also the occurrence of thrombosis and atherosclerosis in certain persons with factor VII deficiency.

Aged↗

Occurrence of blood coagulation factors in situ in small cell carcinoma of the lung.

Through immunohistochemical techniques, blood coagulation factors were identified in situ in fresh frozen sections of small cell carcinoma of the lung. Prothrombin/thrombin, factor VII, factor X, and antithrombin III were present in intercellular spaces and associated with tumor cells. Factor IX, factor XI, prekallikrein, and high molecular weight kininogen were identified as being associated with tumor cells but did not exist in intercellular spaces. Variable connective tissue staining but no tumor-related staining was observed for factor V, factor VIII-related antigen, factor XII, the B subunit of factor XIII, alpha 1-antitrypsin, alpha 2-macroglobulin, or alpha 2-antiplasmin. Neither consecutive tissue nor the tumor manifested platelet Ib and IIbIIIa surface glycoproteins. These divergent staining patterns suggested that the detected clotting factors had not merely diffused from permeabilized blood vessels, but were selectively localized in situ. While conditions may exist within tumor tissue that both retard and promote thrombin generation, we propose that interactions between the observed coagulation factors ultimately lead to local thrombin formation, which is responsible for the conspicuous fibrin deposits already described in small cell carcinoma of the lung. Thrombin formed locally might contribute to progression of this tumor. Inhibition of local thrombin formation by warfarin therapy could explain the beneficial effects of warfarin therapy in treating small cell carcinoma of the lung.

Antigens↗

Inhibition of human factor VIIa-tissue factor activity by placental anticoagulant protein.

Previous studies indicated that human placental anticoagulant protein, a member of the lipocortin family, prolonged the clotting time of normal plasma when clotting was induced by brain thromboplastin or by kaolin in the presence of cephalin and calcium. Using a two-stage amidolytic assay to assess factor X activation and a tritiated peptide release assay to assess factor IX activation, we have examined the ability of purified preparations of placental anticoagulant protein (Mr = 36.5 kDa) to inhibit the activation of either factor X or factor IX by a complex of human factor VIIa-tissue factor. Placental anticoagulant protein markedly inhibits factor X and factor IX activation by factor VIIa-tissue factor in a non-competitive manner with Ki values of 40 nM and 70 nM, respectively. Placental anticoagulant protein had no effect on factor Xa amidolytic activity, and its inhibitory activity was not diminished by prior incubation with antibody raised against partially purified plasma extrinsic pathway inhibitor. Binding of placental anticoagulant protein to phospholipid vesicles, crude tissue factor and purified, relipidated human brain tissue factor apoprotein was observed only in the presence of calcium ions. These results indicate that placental anticoagulant protein is a potent factor VIIa-tissue factor inhibitor and suggests that its mechanism of action involves binding to the phospholipid portion of the tissue factor lipoprotein.

Annexins↗

A new sensitive assay for bovine activated factor XI (factor XIa) using a reconstituted coagulation cascade system.

A sensitive assay for quantitating bovine activated Factor XI (Factor XIa) in vitro was developed by measuring the amidolytic activity of thrombin generated in a mixture of Factors XIa, IX and X and prothrombin prepared from bovine source and washed bovine platelets. In this system, the rate of thrombin generation increased linearly with increasing amounts (fmoles) of Factor XIa. The assay system for Factor XIa was not significantly affected by the presence of plasma kallikrein, Factor XIIa, high-molecular-weight kininogen, amylose sulfate or sulfatide within the range of the amounts used for surface-mediated activation of Factor XII, prekallikrein and Factor XI. Following surface-mediated activation of Factor XI, further generation of Factor XIa was blocked by adding freeze-thawed platelets that contain cationic proteins which bind to negatively-charged surfaces (J. Biochem. 97, 139-151, 1985). The method is useful to the kinetic analysis of the surface-mediated activation of Factors XII and XI, although it is not applicable to the activation in plasma.

Animals↗

Characterization of a protein C activator from Agkistrodon contortrix contortrix venom.

The protease from Southern Copperhead venom that activates protein C was purified to homogeneity by sulfopropyl (SP)-Sephadex C-50 ion-exchange chromatography, Sephadex G-150 gel filtration, and Mono-S fast protein liquid chromatography. The purified enzyme is a glycoprotein containing 16% carbohydrate, and migrated as a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular mass of 40,000 kDa. The enzyme is composed of a single polypeptide chain possessing an NH2-terminal sequence of Val-Ile-Gly-Gly-Asp-Glu-Cys-Asn-Ile-Asn-Glu-His. The purified venom protein C activator hydrolyzed several tripeptide p-nitroanilides. The amidolytic and proteolytic activities of the enzyme were readily inhibited by phenylmethanesulfonyl fluoride, p-amidinophenylmethanesulfonyl fluoride, chloromethyl ketones, and human antithrombin III. Covalent binding of diisopropyl fluorophosphate to the enzyme was confirmed using a tritium-labeled preparation of the inhibitor. The venom protease readily activated human and bovine protein C at 1:1000 enzyme:substrate weight ratio. The protease also cleaved human prothrombin, factor X, factor IX, factor VII, and fibrinogen. Prothrombin coagulant activity decreased upon incubation with the venom protease, and the rate of this reaction was reduced in the presence of calcium. Factor X and factor IX coagulant activity increased upon incubation with the venom protease in the presence of calcium, and decreased in the absence of calcium. Human factor VII clotting activity decreased slightly upon incubation with the venom protease. Although the venom protease did not clot human fibrinogen, it nonetheless cleaved the A alpha chain of fibrinogen, and this cleavage appeared to be associated with a measurable increase in the clottability of the protease-treated fibrinogen by thrombin. These data demonstrate that the protein C activator from Southern Copperhead venom is a typical serine protease with a relatively broad specificity.

Amino Acid Sequence↗

Regulation of factor VIIa activity in plasma: evidence that antithrombin III is the sole plasma protease inhibitor of human factor VIIa.

The inhibition of human factor VIIa by antithrombin III and normal human plasma was studied in the presence and absence of heparin. In the absence of heparin, no apparent inhibition of factor VIIa was observed in either system. In the presence of heparin, factor VIIa activity was inhibited 50% by purified antithrombin III and plasma in 90 min and 75 min, respectively. No inhibition of factor VIIa was observed in heparinized plasma previously depleted of antithrombin III by immunoaffinity adsorption. Incubation of factor VIIa with antithrombin III-heparin or heparinized plasma resulted in the formation of a covalent complex with an apparent molecular weight of 100 kilodaltons. These data indicate that antithrombin III appears to be the sole plasma protease inhibitor of human factor VIIa, and the expression of its inhibitory activity against factor VIIa is absolutely dependent upon the presence of exogenous heparin.

Antithrombin III↗

Isolation of a protein C activator from southern copperhead venom.

A protease from the venom of the Southern Copperhead snake (Agkistrodon contortrix contortrix) that activates protein C was purified to homogeneity by a combination of sulfopropyl (SP)-Sephadex C-50, Sephadex G-150 and Mono-S column chromatography. The purified enzyme is a glycoprotein, and migrated as a single band in sodium dodecylsulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 37,000 under non-reducing conditions. Upon reduction with 2-mercaptoethanol, the enzyme exhibited a Mr of 40,000. The purified enzyme prolonged the clotting time of human plasma in a dose- and temperature-dependent manner. Purified bovine protein C was completely activated within 10 minutes upon incubation with the purified protease at a 1:500 enzyme: substrate ratio. This reaction was markedly inhibited by calcium ions. The purified venom protein C activator had no effect on human fibrinogen.

Animals↗

In vivo evidence of intravascular binding sites for coagulation factor IX.

Previous studies have demonstrated that factors IX/IXa bind to specific sites on the surfaces of cultured and native endothelium in vitro and that these sites should be occupied with factor IX in homeostasis. Since factor IX of different species binds to endothelium in a similar manner, we examined if infusion of heterologous factor IX into an animal should result in displacement of host factor IX antigen from its vessel wall site. Experiments were carried out in baboons with a large excess of bovine factor IX employing species-specific radioimmunoassays. The results indicate that infusion of bovine factor IX or active site-blocked factor IXa, but not prothrombin, resulted in a dose-dependent rise in the plasma level of baboon factor IX antigen. This suggested that the infused factor IX was displacing the host clotting factor from some reservoir easily accessible to the intravascular space. Consistent with this hypothesis, infusion of 125I-factor IX demonstrated accumulation in multiple organs. Radioiodinated factor IX comigrating with the initial tracer on SDS-PAGE could be eluted from the luminal surface of pulmonary artery and aortic segments. 125I-factor IX was not significantly associated with cellular elements of the blood. These results suggest that there is a pool of non-circulating factor IX which is accessible to the intravascular space, widely distributed and involves endothelium.

Animals↗

Evidence that plasma lipoproteins inhibit the factor VIIa-tissue factor complex by a different mechanism that extrinsic pathway inhibitor.

Factor VIIa participates in blood clotting by activating factor X and/or factor IX by limited proteolysis. The proteolytic activity of factor VIIa is absolutely dependent on a lipoprotein cofactor designated tissue factor. We have examined the ability of purified preparations of human plasma high density, low density and very low density lipoproteins, as well as apolipoproteins A-I and A-II, to inhibit the factor VIIa-tissue factor mediated activation of either factor X or factor IX before and after treatment of the lipoprotein preparation with polyclonal antibody directed against partially-purified human plasma extrinsic pathway inhibitor (EPI). In the absence of anti-EPI IgG, HDL, LDL, VLDL, and apolipoprotein A-II noncompetitively inhibited factor X activation by factor VIIa-tissue factor with apparent Ki values of 3.39 mumol/L, 124 nmol/L, 33 nmol/L, and 10.5 mumol/L, respectively. Apolipoprotein A-I had no effect on this reaction. The inhibitory activity of HDL, LDL, VLDL, and apolipoprotein A-II in this reaction was unaffected by the presence of high levels of anti-EPI IgG. In the absence of exogenous factor Xa, none of the lipoproteins studied inhibited the activation of factor IX using the tritiated peptide release assay. In the presence of added factor Xa (1 nmol/L), LDL and VLDL, but not HDL and apolipoprotein A-II, inhibited the activation of factor IX by factor VIIa-tissue factor. This inhibition was completely blocked by prior incubation of the lipoprotein with anti-EPI IgG indicating association of EPI with these particles. Taken collectively, our data indicate that HDL, LDL, and VLDL, at or below their plasma concentration, each selectively inhibits the factor VIIa-tissue factor mediated activation of factor X by a mechanism that appears to be distinct from extrinsic pathway inhibitor. These lipoproteins may not only play a role in the regulation of extrinsic blood coagulation, but may also selectively promote the activation of factor IX by factor VIIa-tissue factor in vivo at low tissue factor concentrations.

Apolipoproteins↗

Carrier testing in hemophilia B with an immunoassay that distinguishes a prevalent factor IX dimorphism.

Immunoassays with a monoclonal antibody (A-1) detect a prevalent dimorphism in plasma coagulation factor IX. The antibody was shown to react with a dimorphic segment of the normal factor IX sequence as follows. First, A-1 bound to isolated activation peptide (residues 146 through 180) prepared from activated factor IX from a normal plasma pool. Second, binding of recombinant factor IXs with A-1 or factor IX from normal individuals was strong only when they had Threonine (Thr) at position 148; factor IXs with the Alanine (Ala) allele at that position were far less reactive. Third, immunoblot reactivity of Escherichia coli fusion proteins containing known segments of the factor IX sequence restricted the epitope to residues 147 through 153. In 120 hemophilia B pedigrees, the Ala immunoassay allele frequency was 0.19 and did not differ from the Ala frequency in normal males. In 22 of 49 families, immunoassay testing was informative for classification of obligate or possible carriers. In one large family, 4 obligate carriers were heterozygous for the dimorphism and 3 of their 7 daughters were classified as carriers. In other families, when the affected member had less than 1 nmol/L factor IX antigen, heterozygosity for Thr/Ala alleles excluded the carrier state even when DNA studies were not informative. Strong linkage disequilibrium of Thr/Ala alleles with the common TaqI DNA polymorphism was found. Nineteen of 75 normal and hemophilic factor IX genes had the 1.3-kilobase (kb) fragment and coded for the Ala allele; the rest had the 1.8-kb fragment and coded for Thr. In selected families, the A-1 immunoassay is an inexpensive and rapid method to confirm and supplement restriction fragment length polymorphism analyses of DNA for carrier testing.

Alleles↗