Effect of Heparin on the Inhibition of Factor Xa by Tissue Factor Pathway Inhibitor: A Segment, Gly212-Phe243, of the Third Kunitz Domain Is a Heparin-Binding Site

Enjyoji, Keiichi; Miyata, Toshiyuki; Kamikubo, Yu-ichi; Kato, Harubumi

doi:10.1021/bi00017a004

Cited by 83 publications

(80 citation statements)

References 44 publications

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“…Under normal conditions, factor Xa, a proteolytic product of factor X, in the presence of factors VII and VIIIa, will bind tissue factor pathway inhibitor on endothelial cells and be internalized via an unknown receptor (70). In the presence of Hep, however, tissue factor pathway inhibitor binds Hep and is released from the endothelium to form complexes that can include factors VIIa and X (71). These complexes may then bind via the Hep, and be internalized and cleared from blood by cells expressing HARE.…”

Section: Discussionmentioning

confidence: 99%

The Human Hyaluronan Receptor for Endocytosis (HARE/Stabilin-2) Is a Systemic Clearance Receptor for Heparin

Harris

Weigel

2008

Journal of Biological Chemistry

107

112

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Heparin (Hep)2 is the most anionic proteoglycan, due to the extensive sulfation of its glycosaminoglycan (GAG) chains, and contains many different sulfated disaccharide isomers of N-acetylgalactosamine and glucuronic acid or iduronic acid. Hep binds to many different soluble, matrix, and cell surface proteins and receptors, and has many functions, including its roles as an anti-coagulant and as a co-receptor for some growth factors (1, 2). Hep is a highly prescribed drug in surgical patients and those at risk for thromobosis. The genes and metabolic pathway for Hep biosynthesis in mast cells are understood reasonably well, and many of the biological and clinical activities of Hep have been well studied for several decades (3-6). In contrast, we know less about the catabolism of Hep and how total body homeostasis of this multifunctional proteoglycan is maintained. In particular, the mechanisms controlling systemic turnover of Hep, whether as endogenous proteoglycan or free chain drugs, are not known.Although receptors for Hep have been characterized on a variety of cell types (e.g. macrophages, vascular smooth muscle cells), none of these mediate substantial clearance of Hep (7-9). A few reports implicated a role for Kupffer cells in Hep clearance, but were not followed up (10, 11). The possible contribution of liver sinusoidal endothelial cells to Hep uptake in these primary cell preparations was not examined. Because Hep is a widely prescribed drug, it is even more important to understand the factors that control its clearance and, therefore, pharmokinetics. Animal studies of Hep clearance, except by renal function, have been difficult to perform, because Hep binds to so many soluble, cell surface or matrix proteins and become widely distributed after injection.Unfractioned Hep (3000 -30000 Da), low molecular mass Hep (300 -8000 Da), and the pentasaccharide, Fondaparinux, are the three classes of Hep drugs used to treat venous thrombosis, acute myocardial infarction, trauma, obesity, and coronary and peripheral vascular procedures; all situations wherein patients need immediate platelet anti-coagulation therapy (12). Following an intravenous bolus, unfractioned Hep has a halflife of ϳ1 h and is cleared from the circulation by the liver and kidney (13). Low molecular mass Hep and the pentasaccharide, subcutaneously injected, have half-lives of ϳ3-6 and ϳ17 h, respectively (14). Larger more structurally diverse Hep is more readily cleared than the lower molecular weight fragments. Although clinical handbooks declare that Hep is metabolized and cleared by the reticuloendothelial system, the mechanisms for Hep clearance are not known.The primary scavenger receptor for systemic turnover of HA and most types of chondroitin sulfate, but not HS, is HARE/ Stab-2, which mediates most of the total body HA turnover per day (15)(16)(17). HARE is found primarily in the sinusoidal endothelial cells of the lymph nodes, liver, and spleen (18 -21), and * This work was supported, in whole or in part, by National Institutes of Hea...

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Section: Discussionmentioning

confidence: 99%

The Human Hyaluronan Receptor for Endocytosis (HARE/Stabilin-2) Is a Systemic Clearance Receptor for Heparin

Harris

Weigel

2008

Journal of Biological Chemistry

107

112

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“…Domains 1 and 2 are required for factor VIIa and Xa binding (4), whereas domain 3, along with the carboxyl terminus of TFPI, can bind to heparin (20). To identify the region of TFPI responsible for this antiproliferative activity, proliferation studies were performed with both full-length TFPI and a truncated TFPI containing only domains 1 and 2 (1-160 a.a.).…”

Section: Tfpi Inhibits Endothelialmentioning

confidence: 99%

Tissue Factor Pathway Inhibitor Inhibits Endothelial Cell Proliferation via Association with the Very Low Density Lipoprotein Receptor

Hembrough

Ruiz

Papathanassiu

et al. 2001

Journal of Biological Chemistry

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Tissue factor pathway inhibitor (TFPI) contains three Kunitz-type proteinase inhibitor domains and is a potent inhibitor of tissue factor-mediated coagulation. Here, we report that TFPI inhibits the proliferation of basic fibroblast growth factor-stimulated endothelial cells. A truncated form of TFPI, containing only the first two Kunitz-type proteinase inhibitor domains, has very little antiproliferative activity, suggesting that the carboxyl-terminal region of TFPI is responsible for this activity. Binding studies revealed that full-length TFPI, but not the truncated TFPI molecule, is recognized by the very low density lipoprotein receptor (VLDL receptor) indicating that this receptor is a novel high affinity endothelial cell receptor for TFPI. The antiproliferative activity of TFPI on endothelial cells is inhibited by the receptor-associated protein, a known antagonist of ligand binding by the VLDL receptor, and by anti-VLDL receptor antibodies. These results confirm that the antiproliferative activity of TFPI is mediated by the VLDL receptor and suggest that this receptor-ligand system may be a useful target for the development of new antiangiogenic and antitumor agents.The extrinsic pathway of blood coagulation is initiated when factor VII (fVII) 1 binds to its cellular receptor, tissue factor (TF). The fVIIa⅐TF complex then functions as a potent enzyme, activating factor X which leads to thrombin generation. In addition to initiating coagulation, recent research suggests that fVIIa⅐TF complexes play an important role in angiogenesis (1-3). Zhang et al. (1) correlated TF expression in tumor cells with the ability of the tumors to secrete vascular endothelial growth factor (VEGF) and, in turn, to induce an angiogenic response when implanted in immunodeficient mice. Although TF is not normally expressed on the surface of vascular endothelial cells, in situ hybridization studies have detected TF mRNA in tumor-associated endothelial cells from patients with invasive breast cancer (2). Finally, in a TF-dependent metastasis model, the binding and proteolytic activity of VIIa was shown to be necessary for the initial steps of tumor metastasis (3).The tissue factor pathway is regulated by a potent inhibitor termed tissue factor pathway inhibitor (TFPI). TFPI forms a tight complex with both fXa and fVIIa leading to their inhibition. The TFPI molecule contains three Kunitz-type domains and a basic carboxyl-terminal region. By employing site-directed mutagenesis, Girard et al. (4) demonstrated that the second Kunitz domain is required for efficient binding and inhibition of fXa, and both Kunitz domains 1 and 2 are required for the inhibition of fVIIa/TF activity. Mutation of the predicted inhibitory residues of the third Kunitz domain had no significant effect on either function of TFPI. Rather, this portion of the molecule binds to the cell surfaces by interacting with cell-surface glycosaminoglycans (5). TFPI can also bind to the low density lipoprotein receptor-related protein (LRP) (6) and, in doing so, mediates ...

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“…A heparin megakaryocytes and chondrocytes (8). There are three binding site C-terminal from domain 53 has been posintravascular pools of tissue factor pathway inhibitor, in tulated as a mediator of heparin-induced tissue factor pathway inhibitor release from the cell surface (15). However, it is also presumed that tissue factor pathway inhibitor is released from intracellular stores (16).…”

Section: Introductionmentioning

confidence: 99%

Detection of the Three Kunitz-Type Single Domains of Membrane-Bound Tissue Factor Pathway Inhibitor (TFPI) by Flow Cytometry

Tiemann¹,

Brinkmann²,

Kleesiek³

1997

CCLM

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Summary:Tissue factor pathway inhibitor, a natural anticoagulant in the extrinsic pathway of blood coagulation, is associated with the endothelial membrane and presumed to be released by heparin.For flow cytometric detection of membrane-bound tissue factor pathway inhibitor we synthesized polyclonal monospecific antibodies directed against each of the three Kunitz-type domains. Antisera were obtained by immunisation of rabbits with synthetic oligopeptides representing the reactive site of each domain. Different cell lines (chondrosarcoma, synovial sarcoma, synovial cells, leukaemic monocytes) and endothelial cells were investigated by flow cytometric analysis using these antibodies. The three tissue factor pathway inhibitor domains were detected on the surface of all cells by the corresponding antisera. Similar results were obtained by immuno-histochemical staining. Since domain 53 was recognised by the appropriate antibody, it would seem that this third domain is not the membrane binding site. To investigate the cellular tissue factor pathway inhibitor release, endothelial cells were cultivated with heparin. Protein resynthesis and translocation were inhibited by puromycin and monensin, respectively. After heparin incubation an increased tissue factor pathway inhibitor concentration was determined in the cell culture medium by a chromogenic substrate assay. However, the tissue factor pathway inhibitor density on the cell surface was not influenced by heparin, as shown by flow cytometry using the three tissue factor pathway inhibitor antisera. Our results suggest that functionally active tissue factor pathway inhibitor is not released from the cell surface. Therefore, the effect of heparin appears to be mediated by secretion of tissue factor pathway inhibitor from intracellular stores. Introductionplasma, in platelets and on the endothelial cell surface.

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Effect of Heparin on the Inhibition of Factor Xa by Tissue Factor Pathway Inhibitor: A Segment, Gly212-Phe243, of the Third Kunitz Domain Is a Heparin-Binding Site

Cited by 83 publications

References 44 publications

The Human Hyaluronan Receptor for Endocytosis (HARE/Stabilin-2) Is a Systemic Clearance Receptor for Heparin

The Human Hyaluronan Receptor for Endocytosis (HARE/Stabilin-2) Is a Systemic Clearance Receptor for Heparin

Tissue Factor Pathway Inhibitor Inhibits Endothelial Cell Proliferation via Association with the Very Low Density Lipoprotein Receptor

Detection of the Three Kunitz-Type Single Domains of Membrane-Bound Tissue Factor Pathway Inhibitor (TFPI) by Flow Cytometry

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