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Schreuder M, Jourdi G, Veizaj D, Poole DA, Cheung KL, Poenou G, Verhoef D, Thomassen S, Janssen LFH, Stepanian A, Hackeng TM, Gaussem P, Reitsma PH, Geerke DP, Siguret V, Bos MHA. Minimally modified human blood coagulation factor X to bypass direct factor Xa inhibitors. J Thromb Haemost 2024; 22:2211-2226. [PMID: 38729577 DOI: 10.1016/j.jtha.2024.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 04/09/2024] [Accepted: 04/23/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND Direct oral factor (F)Xa inhibitors are widely used as alternatives to conventional vitamin K antagonists in managing venous thromboembolism and nonvalvular atrial fibrillation. Unfortunately, bleeding-related adverse events remain a major concern in clinical practice. In case of bleeding or emergency surgery, rapid-onset reversal agents may be required to counteract the anticoagulant activity. OBJECTIVES The ability of FXa variants to bypass the direct oral FXa inhibitors was assessed. METHODS Human FXa variants were generated through substitution of phenylalanine 174 (F174) for either alanine, isoleucine, or serine. FXa variants were stably expressed in HEK293 cells and purified to homogeneity using ion-exchange chromatography. RESULTS F174-substituted human FX variants demonstrated efficacy in restoring thrombin generation in plasma containing direct FXa inhibitors (apixaban, rivaroxaban, edoxaban). Their ability to bypass the anticoagulant effects stems from a significantly reduced sensitivity for the direct FXa inhibitors due to a decrease in binding affinity determined using molecular dynamics simulations and free energy computation. Furthermore, F174 modification resulted in a partial loss of inhibition by tissue factor pathway inhibitor, enhancing the procoagulant effect of F174-substituted FX. Consequently, the F174A- and F174S-substituted FX variants effectively counteracted the effects of 2 widely used anticoagulants, apixaban and rivaroxaban, in plasma of atrial fibrillation and venous thromboembolism patients. CONCLUSION These human FX variants have the potential to serve as a rescue reversal strategy to overcome the effect of direct FXa inhibitors in case of life-threatening bleeding events or emergency surgical interventions.
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Affiliation(s)
- Mark Schreuder
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Georges Jourdi
- Assistance publique - Hôpitaux de Paris (AH-HP) Centre, Service d'hématologie biologique, Hôpital Cochin, Paris, France; Innovative Therapies in Haemostasis, Institut national de la santé et de la recherche médicale (INSERM) U1140, Université Paris Cité, Paris, France; Assistance publique - Hôpitaux de Paris (AH-HP) Nord, Service d'hématologie biologique, Hôpital Lariboisière, Paris, France
| | - Dejvid Veizaj
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - David A Poole
- Amsterdam Institute of Molecular and Life Sciences (AIMMS), Division of Molecular and Computational Toxicology, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Ka Lei Cheung
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Géraldine Poenou
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands; Innovative Therapies in Haemostasis, Institut national de la santé et de la recherche médicale (INSERM) U1140, Université Paris Cité, Paris, France
| | - Daniël Verhoef
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands; VarmX B.V., Leiden, The Netherlands
| | - Stella Thomassen
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Laura F H Janssen
- Amsterdam Institute of Molecular and Life Sciences (AIMMS), Division of Molecular and Computational Toxicology, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Alain Stepanian
- Assistance publique - Hôpitaux de Paris (AH-HP) Nord, Service d'hématologie biologique, Hôpital Lariboisière, Paris, France; EA3518 Institut Universitaire d'Hématologie, Hôpital Saint Louis, Paris-Diderot, Paris, France
| | - Tilman M Hackeng
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Pascale Gaussem
- Innovative Therapies in Haemostasis, Institut national de la santé et de la recherche médicale (INSERM) U1140, Université Paris Cité, Paris, France; Assistance publique - Hôpitaux de Paris (AP-HP) Centre, Service d'hématologie biologique, Hôpital Européen Georges Pompidou, Paris, France
| | - Pieter H Reitsma
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands; VarmX B.V., Leiden, The Netherlands
| | - Daan P Geerke
- Amsterdam Institute of Molecular and Life Sciences (AIMMS), Division of Molecular and Computational Toxicology, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Virginie Siguret
- Innovative Therapies in Haemostasis, Institut national de la santé et de la recherche médicale (INSERM) U1140, Université Paris Cité, Paris, France; Assistance publique - Hôpitaux de Paris (AH-HP) Nord, Service d'hématologie biologique, Hôpital Lariboisière, Paris, France
| | - Mettine H A Bos
- Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands.
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Mohammed BM, Basore K, Summers B, Pelc LA, Di Cera E. Structural architecture of the acidic region of the B domain of coagulation factor V. J Thromb Haemost 2024; 22:709-714. [PMID: 38007061 PMCID: PMC10922652 DOI: 10.1016/j.jtha.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/27/2023]
Abstract
BACKGROUND Coagulation factor (F)V features an A1-A2-B-A3-C1-C2 domain organization and functions as the inactive precursor of FVa, a component of the prothrombinase complex required for rapid thrombin generation in the penultimate step of the coagulation cascade. An intramolecular interaction within the large B domain (residues 710-1545) involves the basic region (BR, residues 963-1008) and acidic region (AR, residues 1493-1537) and locks FV in its inactive state. However, structural information on this important regulatory interaction or on the separate architecture of the AR and BR remains elusive due to conformational disorder of the B domain. OBJECTIVES To reveal the structure of the BR-AR interaction or of its separate components. METHODS The structure of FV is solved by cryogenic electron microscopy. RESULTS A new 3.05 Å resolution cryogenic electron microscopy structure of FV confirms the overall organization of the A and C domains but resolves the segment 1507 to 1545 within a largely disordered B domain. The segment contains most of the AR and is organized as recently reported in FV short, a spliced variant of FV with a significantly shorter and less disordered B domain. CONCLUSION The similar architecture of the AR in FV and FV short provides structural context for physiologically important interactions of this region with the BR in FV and with the basic C-terminal end of tissue factor pathway inhibitor α in FV short.
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Affiliation(s)
- Bassem M Mohammed
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Katherine Basore
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Brock Summers
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Leslie A Pelc
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Enrico Di Cera
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA.
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Mohapatra AK, Todaro AM, Castoldi E. Factor V variants in bleeding and thrombosis. Res Pract Thromb Haemost 2024; 8:102330. [PMID: 38404937 PMCID: PMC10883835 DOI: 10.1016/j.rpth.2024.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/04/2024] [Indexed: 02/27/2024] Open
Abstract
A state-of-the-art lecture titled "Factor V variants in bleeding and thrombosis" was presented at the International Society on Thrombosis and Haemostasis (ISTH) congress in 2023. Blood coagulation is a finely regulated cascade of enzymatic reactions culminating in thrombin formation and fibrin deposition at the site of injury. Factor V (FV) plays a central role in this process, as its activated form is an essential procoagulant cofactor in prothrombin activation. However, other molecular forms of FV act as anticoagulant cofactors of activated protein C and tissue factor pathway inhibitor α, respectively, thereby contributing to the regulation of coagulation. This dual procoagulant and anticoagulant character makes FV a central regulator of the hemostatic balance, and quantitative and qualitative alterations of FV may be associated with an increased risk of bleeding or venous thrombosis. Here, we review the procoagulant and anticoagulant functions of FV and the manifold mechanisms by which F5 gene mutations may affect the balance between these opposite functions and thereby predispose individuals to bleeding or venous thrombosis. In particular, we discuss our current understanding of the 3 main pathological conditions related to FV, namely FV deficiency, activated protein C resistance, and the overexpression of FV-short, a minor splicing isoform of FV with tissue factor pathway inhibitor α-dependent anticoagulant properties and an emerging role as a key regulator of the initiation of coagulation. Finally, we summarize relevant new data on this topic presented during the 2023 ISTH Congress.
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Affiliation(s)
- Adarsh K. Mohapatra
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
| | - Alice M. Todaro
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
| | - Elisabetta Castoldi
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
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Gierula M, Noakes VM, Salles-Crawley II, Crawley JTB, Ahnström J. The TFPIα C-terminal tail is essential for TFPIα-FV-short-protein S complex formation and synergistic enhancement of TFPIα. J Thromb Haemost 2023; 21:3568-3580. [PMID: 37739040 DOI: 10.1016/j.jtha.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/01/2023] [Accepted: 09/07/2023] [Indexed: 09/24/2023]
Abstract
BACKGROUND For maximal TFPIα functionality, 2 synergistic cofactors, protein S and FV-short, are required. Both interact with TFPIα, protein S through Kunitz 3 residues Arg199/Glu226 and FV-short with the C-terminus. How these interactions impact the synergistic enhancement remains unclear. OBJECTIVES To determine the importance of the TFPIα-protein S and TFPIα-FV-short interactions for TFPIα enhancement. METHODS TFPIα variants unable to bind protein S (K3m [R199Q/E226Q]) or FV-short (ΔCT [aa 1-249]) were generated. TFPIα-FV-short binding was studied by plate-binding and co-immunoprecipitation assays; functional TFPIα enhancement by FXa inhibition and prothrombin activation. RESULTS While WT TFPIα and TFPIα K3m bound FV-short with high affinity (Kd∼2nM), TFPIα ΔCT did not. K3m, in contrast to WT, did not incorporate protein S in a TFPIα-FV-short-protein S complex while TFPIα ΔCT bound neither FV-short nor protein S. Protein S enhanced WT TFPIα-mediated FXa inhibition, but not K3m, in the absence of FV-short. However, once FV-short was present, protein S efficiently enhanced TFPIα K3m (EC50: 4.7nM vs 2.0nM for WT). FXa inhibition by ΔCT was not enhanced by protein S alone or combined with FV-short. In FXa-catalyzed prothrombin activation assays, FV-short enhanced TFPIα K3m function in the presence of protein S (5.5 vs 10.4-fold enhancement of WT) whereas ΔCT showed reduced or lack of enhancement by FV-short and protein S, respectively. CONCLUSION Full TFPIα function requires the presence of both cofactors. While synergistic enhancement can be achieved in the absence of TFPIα-protein S interaction, only TFPIα with an intact C-terminus can be synergistically enhanced by protein S and FV-short.
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5
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Maroney SA, Siebert AE, Martinez ND, Rasmussen M, Peterson JA, Weiler H, Lincoln J, Mast AE. Platelet tissue factor pathway inhibitor-α dampens cardiac thrombosis and associated fibrosis in mice. J Thromb Haemost 2023; 21:639-651. [PMID: 36696221 PMCID: PMC10200073 DOI: 10.1016/j.jtha.2022.11.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/17/2022] [Accepted: 11/28/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND Tissue factor pathway inhibitor (TFPI) is the primary inhibitor of events initiating the blood coagulation pathway. Tfpi-/- mice die during embryonic development. The absence of protease-activated receptor (PAR) 4, the major thrombin receptor on mouse platelets, rescues Tfpi-/-mice to adulthood. Among the 3 TFPI isoforms in mice, TFPIα is the only isoform within platelets (pltTFPIα) and the only isoform that inhibits prothrombinase, the enzymatic complex that converts prothrombin to thrombin. OBJECTIVES To determine biological functions of pltTFPIα. METHODS Tfpi-/-/Par4-/- mice were irradiated and transplanted with bone marrow from mice lacking or containing pltTFPIα. Thus, PAR4 expression was restored in the recipient mice, which differed selectively by the presence or absence of pltTFPIα and lacked other forms of TFPI. RESULTS Recipient mice lacking pltTFPIα had reduced survival over the 200-day posttransplant period. Necropsy revealed radiation injury associated with large intraventricular platelet-rich thrombi, whereas other organs were not affected. Thrombi were associated with fibrotic presentations, including increased collagen deposition, periostin-positive activated fibroblasts, myofibroblasts, and macrophage infiltrates. Recipient mice containing pltTFPIα showed evidence of radiation injury but lacked heart pathology. CONCLUSIONS Tfpi-/-/Par4-/- mice develop severe cardiac fibrosis following irradiation and transplantation with bone marrow lacking pltTFPIα. This pathology is markedly reduced when the mice are transplanted with bone marrow containing pltTFPIα. Thus, in this model system pltTFPIα has an important physiological role in dampening pathological responses mediated by activated platelets within the heart tissue.
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Affiliation(s)
- Susan A Maroney
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA
| | - Amy E Siebert
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA
| | - Nicholas D Martinez
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA
| | - Mark Rasmussen
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA
| | - Julie A Peterson
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA
| | - Hartmut Weiler
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joy Lincoln
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA; Division of Pediatric Cardiology, The Herma Heart Institute, Children's Wisconsin, Milwaukee, WI, USA
| | - Alan E Mast
- Thrombosis and Hemostasis Program, Versiti Blood Research Institute, Milwaukee, WI, USA; Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
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6
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Dahlbäck B. Natural anticoagulant discovery, the gift that keeps on giving: finding FV-Short. J Thromb Haemost 2023; 21:716-727. [PMID: 36746318 DOI: 10.1016/j.jtha.2023.01.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 01/24/2023] [Accepted: 01/24/2023] [Indexed: 02/05/2023]
Abstract
The complex reactions of blood coagulation are balanced by several natural anticoagulants resulting in tuned hemostasis. During several decades, the knowledge base of the natural anticoagulants has greatly increased and we have also learned about antiinflammatory and cytoprotective activities expressed by antithrombin and activated protein C (APC). Some coagulation proteins have also been found to function as anticoagulants; e.g., thrombin when bound to thrombomodulin activates protein C. Another example is factor V (FV), which in addition to being a procofactor to FVa has emerged as an anticoagulant. The discovery of APC resistance, caused by FVLeiden, as a thrombosis risk factor resulted in the identification of FV as an APC cofactor working in synergy with protein S in the regulation of FVIIIa in the Xase complex. More recently, a natural anticoagulant FV splice isoform (FV-Short) was discovered when investigating the East Texas bleeding disorder. In FV-Short, the truncated B domain exposes a high-affinity binding site for tissue factor pathway inhibitor alpha (TFPIα), and together with protein S a high-affinity trimolecular complex is generated. The FXa-inhibitory activity of TFPIα is synergistically stimulated by FV-Short and protein S. The circulating FV-Short/protein S/TFPIα complex concentration is normally low (≈0.2 nM) but provides an anticoagulant threshold. In the East Texas bleeding, the concentration of the complex, and thus the threshold, is increased 10-fold, which results in bleeding manifestations. The anticoagulant properties of FV were discovered during investigations of individual patients and follow the great tradition of bed-to-bench and bench-to-bed research in the coagulation field.
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Affiliation(s)
- Björn Dahlbäck
- Department of Translational Medicine, University Hospital, Lund University, 21428 Malmö, Sweden.
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7
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Miyazawa K, Fogelson AL, Leiderman K. Inhibition of platelet-surface-bound proteins during coagulation under flow I: TFPI. Biophys J 2023; 122:99-113. [PMID: 36403087 PMCID: PMC9822800 DOI: 10.1016/j.bpj.2022.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 09/01/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
Blood coagulation is a self-repair process regulated by activated platelet surfaces, clotting factors, and inhibitors. Tissue factor pathway inhibitor (TFPI) is one such inhibitor, well known for its inhibitory action on the active enzyme complex comprising tissue factor (TF) and activated clotting factor VII. This complex forms when TF embedded in the blood vessel wall is exposed by injury and initiates coagulation. A different role for TFPI, independent of TF:VIIa, has recently been discovered whereby TFPI binds a partially cleaved form of clotting factor V (FV-h) and impedes thrombin generation on activated platelet surfaces. We hypothesized that this TF-independent inhibitory mechanism on platelet surfaces would be a more effective platform for TFPI than the TF-dependent one. We examined the effects of this mechanism on thrombin generation by including the relevant biochemical reactions into our previously validated mathematical model. Additionally, we included the ability of TFPI to bind directly to and inhibit platelet-bound FXa. The new model was sensitive to TFPI levels and, under some conditions, TFPI could completely shut down thrombin generation. This sensitivity was due entirely to the surface-mediated inhibitory reactions. The addition of the new TFPI reactions increased the threshold level of TF needed to elicit a strong thrombin response under flow, but the concentration of thrombin achieved, if there was a response, was unchanged. Interestingly, we found that direct binding of TFPI to platelet-bound FXa had a greater anticoagulant effect than did TFPI binding to FV-h alone, but that the greatest effects occurred if both reactions were at play. The model includes activated platelets' release of FV species, and we explored the impact of varying the FV/FV-h composition of the releasate. We found that reducing the zymogen FV fraction of this pool, and thus increasing the fraction that is FV-h, led to acceleration of thrombin generation.
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Affiliation(s)
- Kenji Miyazawa
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado
| | - Aaron L Fogelson
- Department of Mathematics, University of Utah, Salt Lake City, Utah; Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah
| | - Karin Leiderman
- Mathematics Department, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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8
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Ariëns RA, Hunt BJ, Agbani EO, Ahnström J, Ahrends R, Alikhan R, Assinger A, Bagoly Z, Balduini A, Barbon E, Barrett CD, Batty P, Carneiro JDA, Chan W, de Maat M, de Wit K, Denis C, Ellis MH, Eslick R, Fu H, Hayward CPM, Ho‐Tin‐Noé B, Klok F, Kumar R, Leiderman K, Litvinov RI, Mackman N, McQuilten Z, Neal MD, Parker WAE, Preston RJS, Rayes J, Rezaie AR, Roberts LN, Rocca B, Shapiro S, Siegal DM, Sousa LP, Suzuki‐Inoue K, Zafar T, Zhou J. Illustrated State-of-the-Art Capsules of the ISTH 2022 Congress. Res Pract Thromb Haemost 2022; 6:e12747. [PMID: 35814801 PMCID: PMC9257378 DOI: 10.1002/rth2.12747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
The ISTH London 2022 Congress is the first held (mostly) face-to-face again since the COVID-19 pandemic took the world by surprise in 2020. For 2 years we met virtually, but this year's in-person format will allow the ever-so-important and quintessential creativity and networking to flow again. What a pleasure and joy to be able to see everyone! Importantly, all conference proceedings are also streamed (and available recorded) online for those unable to travel on this occasion. This ensures no one misses out. The 2022 scientific program highlights new developments in hemophilia and its treatment, acquired and other inherited bleeding disorders, thromboinflammation, platelets and coagulation, clot structure and composition, fibrinolysis, vascular biology, venous thromboembolism, women's health, arterial thrombosis, pediatrics, COVID-related thrombosis, vaccine-induced thrombocytopenia with thrombosis, and omics and diagnostics. These areas are elegantly reviewed in this Illustrated Review article. The Illustrated Review is a highlight of the ISTH Congress. The format lends itself very well to explaining the science, and the collection of beautiful graphical summaries of recent developments in the field are stunning and self-explanatory. This clever and effective way to communicate research is revolutionary and different from traditional formats. We hope you enjoy this article and will be inspired by its content to generate new research ideas.
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Affiliation(s)
| | | | - Ejaife O. Agbani
- Department of Physiology and Pharmacology, Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
| | | | - Robert Ahrends
- Institute of Analytical ChemistryUniversity of ViennaViennaAustria
| | - Raza Alikhan
- Haemostasis & ThrombosisUniversity Hospital of WalesCardiffUK
| | | | - Zsuzsa Bagoly
- Faculty of Medicine, Department of Laboratory Medicine, Division of Clinical Laboratory Sciences and ELKH‐DE Neurodegenerative and Cerebrovascular Research GroupUniversity of DebrecenDebrecenHungary
| | | | - Elena Barbon
- San Raffaele Telethon Institute for Gene TherapyIRCCS San Raffaele Scientific InstituteMilanItaly
| | - Christopher D. Barrett
- Division of Acute Care Surgery and Surgical Critical Care, Department of SurgeryUniversity of Nebraska Medical CenterOmahaNebraskaUSA
- Koch Institute, Center for Precision Cancer MedicineMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
- Division of Surgical Critical Care, Department of Surgery, Boston University Medical CenterBoston University School of MedicineBostonMassachusettsUSA
| | | | | | - Wee Shian Chan
- University of British ColumbiaVancouverBritish ColumbiaCanada
| | - Moniek de Maat
- Department of HematologyErasmus MCRotterdamThe Netherlands
| | - Kerstin de Wit
- Queen’s University and McMaster UniversityKingstonONCanada
| | | | - Martin H. Ellis
- Hematology Institute and Blood Bank, Meir Medical Center and Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
| | - Renee Eslick
- Haematology DepartmentCanberra HospitalGarranAustralian Capital TerritoryAustralia
| | - Hongxia Fu
- Division of Hematology, Department of MedicineUniversity of WashingtonSeattleWashingtonUSA
| | | | | | - Frederikus A. Klok
- Department of Medicine – Thrombosis and HemostasisLeiden University Medical CenterLeidenThe Netherlands
| | - Riten Kumar
- Dana Farber/Boston Children’s Cancer and Blood Disorders CenterBostonMassachusettsUSA
| | | | - Rustem I. Litvinov
- Department of Cell and Developmental BiologyUniversity of Pennsylvania School of MedicinePhiladelphiaPennsylvaniaUSA
| | - Nigel Mackman
- UNC Blood Research Center, Division of Hematology, Department of MedicineUniversity of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | | | - Matthew D. Neal
- Trauma and Transfusion Medicine Research Center, Department of SurgeryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - William A. E. Parker
- Cardiovascular Research Unit, Northern General HospitalUniversity of SheffieldSheffieldUK
| | - Roger J. S. Preston
- Irish Centre for Vascular Biology, Department of Pharmacy & Biomolecular SciencesRoyal College of Surgeons in IrelandDublin 2Ireland
| | | | - Alireza R. Rezaie
- Cardiovascular Biology Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Lara N. Roberts
- King’s Thrombosis Centre, Department of Haematological MedicineKing’s College Hospital NHS Foundation TrustLondonUK
| | - Bianca Rocca
- Department of Safety and Bioethics, Section of PharmacologyCatholic University School of MedicineRomeItaly
| | - Susan Shapiro
- Oxford University Hospitals NHS Foundation TrustOxfordUK
- Radcliffe Department of MedicineOxford UniversityOxfordUK
| | - Deborah M. Siegal
- Ottawa Hospital Research Institute and University of OttawaOttawaOntarioCanada
| | - Lirlândia P. Sousa
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de FarmáciaUniversidade Federal de Minas GeraisBelo HorizonteBrazil
| | - Katsue Suzuki‐Inoue
- Department of Clinical and Laboratory MedicineUniversity of YamanashiYamanashiJapan
| | - Tahira Zafar
- Frontier Medical CollegeAbbotabadPakistan
- Hemophilia Treatment CenterRawalpindiPakistan
| | - Jiaxi Zhou
- Institute of Hematology & Blood Diseases HospitalChinese Academy of Medical Sciences & Peking Union Medical CollegeTianjinChina
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9
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Mast AE, Ruf W. Regulation of coagulation by tissue factor pathway inhibitor: Implications for hemophilia therapy. J Thromb Haemost 2022; 20:1290-1300. [PMID: 35279938 PMCID: PMC9314982 DOI: 10.1111/jth.15697] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/08/2022] [Accepted: 03/07/2022] [Indexed: 11/27/2022]
Abstract
Tissue factor pathway inhibitor (TFPI) is an alternatively spliced anticoagulant protein that primarily dampens the initiation phase of coagulation before thrombin is generated. As such, TFPI's actions are localized to cells expressing TF and to sites of injury, where it is an important regulator of bleeding in hemophilia. The major splice isoforms TFPIα and TFPIβ localize to different sites within and surrounding the vasculature. Both forms directly inhibit factor Xa (FXa) via their Kunitz 2 domain and inhibit TF-FVIIa via their Kunitz 1 domain in a tight complex primarily localized to cells. By forming complexes localized to distinct cellular microenvironments and engaging additional cell surface receptors, TFPI alters cellular trafficking and signaling pathways driven by coagulation proteases of the TF pathway. TFPIα, which circulates in complex with FV and protein S, also serves an inhibitor of FXa independent of the TF initiation complex and prevents the formation of an active prothrombinase. This regulation of thrombin generation in the context of vessel injury is effectively blocked by antibodies to Kunitz 2 domain of TFPI and exploited as a therapy to restore efficient hemostasis in hemophilia.
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Affiliation(s)
- Alan E. Mast
- Versiti Blood Research InstituteMilwaukeeWisconsinUSA
| | - Wolfram Ruf
- Center for Thrombosis and HemostasisJohannes Gutenberg University Medical CenterMainzGermany
- Department of Immunology and MicrobiologyScripps ResearchLa JollaCaliforniaUSA
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Dahlbäck B, Tran S. A hydrophobic patch (PLVIVG; 1481-1486) in the B-domain of factor V-short is crucial for its synergistic TFPIα-cofactor activity with protein S and for the formation of the FXa-inhibitory complex comprising FV-short, TFPIα, and protein S. J Thromb Haemost 2022; 20:1146-1157. [PMID: 35247027 PMCID: PMC9313797 DOI: 10.1111/jth.15690] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/09/2022] [Accepted: 02/25/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)-cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493-1537) in the B domain binds TFPIα. The preAR2 (1458-1492) is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα. OBJECTIVE To identify which part of preAR2 is required for the synergistic TFPIα-cofactor activity between FV-short and protein S. METHODS A FXa-inhibition assay was used to test the synergistic TFPIα cofactor activity between protein S and new FV-short variants FV709-1476, FV712-1478, FV712-1481, FV712-1484, FV712-1487, and FV712-1490. A microtiter-based assay analyzed binding among FV-short variants, protein S, and TFPIα. RESULTS FV709-1476, FV712-1478, and FV712-1481 were fully active as synergistic TFPIα cofactors with protein S; FV712-1484 showed intermediate activity; and FV712-1487 and FV712-1490 were inactive. TFPIα interacted with all variants in the absence of protein S but FV712-1478 and FV712-1481 bound TFPIα with highest affinity. None of the FV-short variants bound directly to protein S in the absence of TFPIα. In the presence of TFPIα, efficient cooperative binding was demonstrated between protein S, TFPIα, and FV709-1476, FV712-1478, or FV712-1481. In contrast, no cooperativity among TFPIα, protein S, and FV712-1484, FV712-1487, or FV712-1490 was seen. CONCLUSION A short hydrophobic patch in preAR2 (PLVIVG, 1481-1486) in FV-short is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for the assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα.
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Affiliation(s)
- Björn Dahlbäck
- Department of Translational MedicineUniversity HospitalLund UniversityMalmöSweden
| | - Sinh Tran
- Department of Translational MedicineUniversity HospitalLund UniversityMalmöSweden
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Antisense-Mediated Down-Regulation of Factor V-Short Splicing in a Liver Cell Line Model. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11209621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coagulation factor V (FV) is a liver-derived protein encoded by the F5 gene. Alternative splicing of F5 exon 13 produces a low-abundance splicing isoform, known as FV-short, which binds the anticoagulant protein tissue factor pathway inhibitor (TFPIα) with high affinity, stabilising it in the circulation and potently enhancing its anticoagulant activity. Accordingly, rare F5 gene mutations that up-regulate FV-short splicing are associated with bleeding. In this study we have explored the possibility of decreasing FV-short splicing by antisense-based splicing modulation. To this end, we have designed morpholino antisense oligonucleotides (MAOs) targeting the FV-short-specific donor and acceptor splice sites and tested their efficacy in a liver cell line (HepG2) that naturally expresses full-length FV and FV-short. Cells were treated with 0–20 µM MAO, and full-length FV and FV-short mRNA expression was analysed by RT-(q)PCR. Both MAOs, alone or in combination, decreased the FV-short/full-length FV mRNA ratio down to ~50% of its original value in a specific and dose-dependent manner. This pilot study provides proof-of-principle for the possibility to decrease FV-short expression by antisense-mediated splicing modulation. In turn, this may form the basis for novel therapeutic approaches to bleeding disorders caused by FV-short over-expression and/or elevated TFPIα (activity) levels.
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