scholarly journals Protease-activated receptor 2 exacerbates cisplatin-induced nephrotoxicity

2019 ◽  
Vol 316 (4) ◽  
pp. F654-F659 ◽  
Author(s):  
Mari Watanabe ◽  
Yuji Oe ◽  
Emiko Sato ◽  
Akiyo Sekimoto ◽  
Hiroshi Sato ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Factor Viia ◽  
Therapeutic Option ◽  
Factor Xa ◽  
Kidney Injury ◽  
Coagulation Cascade ◽  
Expression Levels ◽  
Cisplatin Nephrotoxicity ◽  
Protease Activated Receptor 2

Acute kidney injury (AKI) is associated with hypercoagulability. Tissue factor/factor VIIa complex and factor Xa in the coagulation cascade activate protease-activated receptor 2 (PAR2). Previously, we have shown that PAR2-mediated inflammation aggravates kidney injury in models of diabetic kidney disease and adenine-induced renal fibrosis. However, the role of PAR2 in AKI remains unclear. To clarify the role of PAR2, we administered cisplatin, one of the most common causal factors of AKI, to wild-type and PAR2-deficient mice. The expression levels of tissue factor and PAR2 were significantly increased in the kidneys of mice that were administered cisplatin. A lack of PAR2 corrected the levels of plasma blood urea nitrogen and creatinine as well as ameliorated the acute tubular injury score in the kidney. A lack of PAR2 corrected the infiltration of neutrophils and the gene expression levels of proinflammatory cytokines/chemokines in these mouse kidneys. Similarly, apoptotic markers, such as cleaved caspase-3-positive area and Bax/Bcl2 ratio, were attenuated via PAR2 deletion. Thus, elevated PAR2 exacerbates cisplatin nephrotoxicity, and targeting PAR2 is a novel therapeutic option that aids in the treatment of patients with cisplatin-induced AKI.

Apixaban, a direct factor Xa inhibitor, inhibits tissue-factor induced human platelet aggregation in vitro: Comparison with direct inhibitors of factor VIIa, XIa and thrombin

2010 ◽  
Vol 104 (08) ◽  
pp. 302-310 ◽  
Author(s):  
Xiaosui Jiang ◽  
Pancras Wong
Keyword(s):  
Platelet Aggregation ◽  
Tissue Factor ◽  
Factor Viia ◽  
Human Platelet ◽  
Factor Xa ◽  
Coagulation Cascade ◽  
Human Platelet Aggregation ◽  
Direct Inhibitors ◽  
Vitro Effect

SummaryApixaban is an oral, direct and highly selective factor Xa (FXa) inhibitor in late-stage clinical development. This study evaluated the in vitro effect of apixaban on human platelet aggregation induced by thrombin derived via the extrinsic pathway. Direct inhibitors of FXa (rivaroxaban), FVIIa (BMS-593214), thrombin (dabigatran, argatroban) and FXIa (BMS-262084) were included for comparison. Citrated human plateletsrich plasma (PRP) was treated with 50 μg/ml corn trypsin inhibitor (to block the contact factor pathway) and 3 mM H-Gly-Pro-Arg- Pro-OH-AcOH (to prevent fibrin polymerisation). Human tissue factor (TF) (Innovin®; dilution 1:1,000 to 1:1,500) plus 7.5 mM CaCl2 was added to PRP pre-incubated with vehicle or increasing concentrations of inhibitors. The TF-induced platelet aggregation was measured by optical aggregometry. TF produced 85 ± 3% aggregation of human platelets in the vehicle-treated group (n=10). Apixaban and other factor inhibitors, except the FXIa inhibitor, inhibited TF-induced platelet aggregation with IC50 (nM) values as follows: 4 ± 1 (apixaban), 8 ± 2 (rivaroxaban), 13 ± 1 (BMS-593214), 46 ± 1 (dabigatran) and 79 ± 1 (argatroban). BMS-262084 (IC50 = 2.8 nM vs. human FXIa) had no effect on TF-induced platelet aggregation at 10 μM. These inhibitors at 10 μM had no effect on platelet aggregation induced by ADP and collagen, as expected from their mechanism of action. This study demonstrates that inhibition of thrombin generation by blocking upstream proteases (FVIIa and FXa) in the blood coagulation cascade is as effective as direct thrombin inhibition in preventing TF-induced platelet aggregation. Under these experimental conditions, a FXIa inhibitor did not prevent TF-induced platelet aggregation.

scholarly journals Tissue Factor Pathway Inhibitor Blocks Cellular Effects of Endotoxin by Binding to Endotoxin and Interfering With Transfer to CD14

Blood ◽  
1997 ◽  
Vol 89 (12) ◽  
pp. 4268-4274 ◽  
Author(s):  
C. Thomas Park ◽  
Abla A. Creasey ◽  
Samuel D. Wright
Keyword(s):  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Feedback Inhibition ◽  
Factor Viia ◽  
Endotoxic Shock ◽  
Factor Xa ◽  
Lethal Effect ◽  
Coagulation Cascade ◽  
Tissue Factor Pathway

Abstract Tissue factor pathway inhibitor (TFPI) is a Kunitz-type plasma protease inhibitor that inhibits factor Xa and the factor VIIa/tissue factor catalytic complex. It plays an important role in feedback inhibition of the coagulation cascade (Broze, Annu Rev Med 46:103, 1995). TFPI has also been used successfully to prevent lethality and attenuate coagulopathic responses in a baboon model of septic shock (Creasey et al, J Clin Invest 91:2850, 1993; and Carr et al, Circ Shock 44:126, 1995). However, the mechanism of reduced mortality in these animals could not be explained merely by the anticoagulant effect of TFPI, because TFPI-treated animals also had a significantly depressed interleukin-6 response. Moreover, inhibition of coagulopathic responses by other anticoagulants has failed to block the organ damage or lethal effect of endotoxic shock (Coalson et al, Circ Shock 5:423, 1978; Warr et al, Blood 75:1481, 1990; and Taylor et al, Blood 78:364, 1991). We show here that recombinant TFPI can bind to endotoxin in vitro. This binding prevents interaction of endotoxin with both lipopolysaccharide binding protein and CD14, thereby blocking cellular responses.

Factors Affecting the lnteraction of Tissue Factor/Factor Vll with Factor X in a Heterogeneous Tubular Reactor

1991 ◽  
Vol 65 (02) ◽  
pp. 139-143 ◽  
Author(s):  
Cynthia H Gemmell ◽  
Vincet T Turitto ◽  
Yale Nemerson
Keyword(s):  
Steady State ◽  
Tissue Factor ◽  
Factor Viia ◽  
Transmembrane Protein ◽  
Strong Association ◽  
Tubular Reactor ◽  
Factor Xa ◽  
Phospholipid Bilayer ◽  
Factor Vii ◽  
Factor X

SummaryA novel reactor recently described for studying phospholipiddependent blood coagulation reactions under flow conditions similar to those occurring in the vasculature has been further charactenzed. The reactor is a capitlary whose inner wall is coated with a stable phospholipid bilayer (or two bilayers) containing tissue factor, a transmembrane protein that is required for the enzymatic activation of factor X by factor VIIa. Perfusion of the capillary at wall shear rates ranging from 25 s−1 to 1,200 s−1 with purified bovine factors X and VIIa led to steady state factor Xa levels at the outlet. Assay were performed using a chromogenic substrate, SpectrozymeTMFXa, or by using a radiometric technique. In the absence of Ca2+ or factor VIIa there was no product formation. No difference was noted in the levels of factor Xa achieved when non-activated factor VII was perfused. Once steady state was achieved further factor Xa production continued in the absence of factor VIIa implying a very strong association of factor VIIa with the tissue factor in the phospholipid membrane. In agreement with static vesicle-type studies the reactor was sensitive to wall tissue factor concentration, temperature and the presence of phosphatidylserine in the bilayer.

The Factor VIII Bypassing Activity of Prothrombin Complex Concentrates: The Roles of Factor VIla and of Endothelial Cell Tissue Factor

1991 ◽  
Vol 66 (05) ◽  
pp. 559-564 ◽  
Author(s):  
Jerome M Teitel
Keyword(s):  
Factor Viii ◽  
Tissue Factor ◽  
Factor Viia ◽  
Factor Xa ◽  
Procoagulant Activity ◽  
Tissue Factor Expression ◽  
Prothrombin Complex Concentrates ◽  
Cell Tissue ◽  
Factor Expression ◽  
Necrosis Factor

SummaryAn experimental model incorporating cultured endothelial cells (EC) was used to study the "factor VIII bypassing" activity of prothrombin complex concentrates (PCC), a property exploited in the treatment of hemophiliacs with alloantibodies to factor VIII. Two PCC preparations were ineffective as stimuli of tissue factor expression by EC. However, incubation with a combination of PCC plus endotoxin (lipopolysaccharide, LPS) or tumor necrosis factor (TNF) induced much greater tissue factor expression than was seen in response to either substance alone. PCC expressed an additional direct procoagulant activity at the EC surface, which could not be attributed to either thrombin or factor Xa, and which was diminished by an anti-tissue factor antibody. Therefore factor VIIa, which was detectable in both PCC preparations, likely provided this additional direct procoagulant activity at the EC surface. We also excluded the possibility that coagulation proteases contained in or generated in the presence of PCC are protected from inactivation by AT III. Therefore, PCC can indirectly bypass factor VIII by enhancing induced endothelial tissue factor expression, and also possess direct procoagulant activity, probably mediated by factor VIIa.

Factor Xa Enhances the Binding of Tissue Factor Pathway Inhibitor to Acidic Phospholipids

1996 ◽  
Vol 75 (05) ◽  
pp. 796-800 ◽  
Author(s):  
Sanne Valentin ◽  
Inger Schousboe
Keyword(s):  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Factor Xa ◽  
Microtitre Plate ◽  
C Terminus ◽  
Microtitre Plate Assay ◽  
Kunitz Domain ◽  
Tissue Factor Pathway ◽  
Acidic Phospholipids

SummaryIn the present study, the interaction between tissue factor pathway inhibitor (TFPI) and phospholipids has been characterized using a microtitre plate assay. TFPI was shown to bind calcium-independently to an acidic phospholipid surface composed of phosphatidylserine, but not a surface composed of the neutral phosphatidylcholine. The interaction was demonstrated to be dependent on the presence of the TFPI C-terminus. The presence of heparin (1 U/ml, unfractionated) was able to significantly reduce the binding of TFPI to phospholipid. The interaction of TFPI with phosphatidylserine was significantly decreased in the presence of calcium, but this was counteracted, and even enhanced, following complex formation of TFPI with factor Xa prior to incubation with the phospholipid surface. Moreover, a TFPI variant, not containing the third Kunitz domain and the C-terminus, was unable to bind to phospholipid. However, following the formation of a TFPI/factor Xa-complex this TFPI variant was capable of interacting with the phospholipid surface. This indicates that the role of factor Xa as a TFPI cofactor, at least in part, is to mediate the binding of TFPI to the phospholipid surface.

scholarly journals Cellular localization and trafficking of tissue factor

Blood ◽  
2006 ◽  
Vol 107 (12) ◽  
pp. 4746-4753 ◽  
Author(s):  
Samir K. Mandal ◽  
Usha R. Pendurthi ◽  
L. Vijaya Mohan Rao
Keyword(s):  
Cell Surface ◽  
Tissue Factor ◽  
Cellular Localization ◽  
Factor Viia ◽  
Coagulation Cascade ◽  
Clotting Factor ◽  
Cell Surfaces ◽  
Caveolin 1 ◽  
Intracellular Compartments ◽  
Resultant Increase

AbstractTissue factor (TF) is the cellular receptor for clotting factor VIIa (FVIIa). The formation of TF-FVIIa complexes on cell surfaces triggers the activation of coagulation cascade and cell signaling. In the present study, we characterized the subcellular distribution of TF and its transport in fibroblasts by dual immunofluorescence confocal microscopy and biochemical methods. Our data show that a majority of TF resides in various intracellular compartments, predominantly in the Golgi. Tissue factor at the cell surface is localized in cholesterol-rich lipid rafts and extensively colocalized with caveolin-1. FVIIa binding to TF induces the internalization of TF. Of interest, we found that TF-FVIIa complex formation at the cell surface leads to TF mobilization from the Golgi with a resultant increase in TF expression at the cell surface. This process is dependent on FVIIa protease activity. Overall, the present data suggest a novel mechanism for TF expression at the cell surface by FVIIa. This mechanism could play an important role in hemostasis in response to vascular injury by increasing TF activity where and when it is needed.

The role of monocytes in thrombotic disorders

2009 ◽  
Vol 102 (11) ◽  
pp. 916-924 ◽  
Author(s):  
Gregory Lip ◽  
Eduard Shantsila
Keyword(s):  
Innate Immunity ◽  
Dendritic Cells ◽  
Tissue Factor ◽  
Physiological Role ◽  
Coagulation Cascade ◽  
Pathophysiological Role ◽  
Platelet Aggregates

SummaryAlthough, the main physiological role of monocytes is attributed to innate immunity (that is, phagocytosis) and the development of tissue macrophages and dendritic cells, the pathophysiological role of these goes far behind these (simplistic) limits. Indeed, monocytes constitute a major source of blood tissue factor, a key element of the extrinsic coagulation cascade. Monocytes actively bind to platelets, thus forming very prothrombotic monocyte-platelet aggregates. Additionally, these cells link inflammation and the procoagulant state observed in various prothrombotic conditions. However, monocytes are also crucial for successful thrombus recanalisation. In this article, we review the available data on potential mechanisms that link monocytes with thrombosis-related processes.

scholarly journals In Hemophilia Α Plasma Treated with Emicizumab, Factor IX Activation By Factor VIIa Drives Thrombin Generation

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 17-17
Author(s):  
Dougald Monroe ◽  
Mirella Ezban ◽  
Maureane Hoffman
Keyword(s):  
Factor Viii ◽  
Tissue Factor ◽  
Plasma Levels ◽  
Thrombin Generation ◽  
Hemophilia A ◽  
Factor Viia ◽  
Factor Ix ◽  
Factor X ◽  
Dose Dependent

Background.Recently a novel bifunctional antibody (emicizumab) that binds both factor IXa (FIXa) and factor X (FX) has been used to treat hemophilia A. Emicizumab has proven remarkably effective as a prophylactic treatment for hemophilia A; however there are patients that still experience bleeding. An approach to safely and effectively treating this bleeding in hemophilia A patients with inhibitors is recombinant factor VIIa (rFVIIa). When given at therapeutic levels, rFVIIa can enhance tissue factor (TF) dependent activation of FX as well as activating FX independently of TF. At therapeutic levels rFVIIa can also activate FIX. The goal of this study was to assess the role of the FIXa activated by rFVIIa when emicizumab is added to hemophilia A plasma. Methods. Thrombin generation assays were done in plasma using 100 µM lipid and 420 µM Z-Gly-Gly-Arg-AMC with or without emicizumab at 55 µg/mL which is the clinical steady state level. The reactions were initiated with low (1 pM) tissue factor (TF). rFVIIa was added at concentrations of 25-100 nM with 25 nM corresponding to the plasma levels achieved by a single clinical dose of 90 µg/mL. To study to the role of factor IX in the absence of factor VIII, it was necessary to create a double deficient plasma (factors VIII and IX deficient). This was done by taking antigen negative hemophilia B plasma and adding a neutralizing antibody to factor VIII (Haematologic Technologies, Essex Junction, VT, USA). Now varying concentrations of factor IX could be reconstituted into the plasma to give hemophilia A plasma. Results. As expected, in the double deficient plasma with low TF there was essentially no thrombin generation. Also as expected from previous studies, addition of rFVIIa to double deficient plasma gave a dose dependent increase in thrombin generation through activation of FX. Interestingly addition of plasma levels of FIX to the rFVIIa did not increase thrombin generation. Starting from double deficient plasma, as expected emicizumab did not increase thrombin generation since no factor IX was present. Also, in double deficient plasma with rFVIIa, emicizumab did not increase thrombin generation. But in double deficient plasma with FIX and rFVIIa, emicizumab significantly increased thrombin generation. The levels of thrombin generation increased in a dose dependent fashion with higher concentrations of rFVIIa giving higher levels of thrombin generation. Conclusion. Since addition of FIX to the double deficient plasma with rFVIIa did not increase thrombin generation, it suggests that rFVIIa activation of FX is the only source of the FXa needed for thrombin generation. So in the absence of factor VIII (or emicizumab) FIX activation does not contribute to thrombin generation. However, in the presence of emicizumab, while rFVIIa can still activate FX, FIXa formed by rFVIIa can complex with emicizumab to provide an additional source of FX activation. Thus rFVIIa activation of FIX explains the synergistic effect in thrombin generation observed when combining rFVIIa with emicizumab. The generation of FIXa at a site of injury is consistent with the safety profile observed in clinical use. Disclosures Monroe: Novo Nordisk:Research Funding.Ezban:Novo Nordisk:Current Employment.Hoffman:Novo Nordisk:Research Funding.

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