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Brenner EE, Alexander AB, Londoño LA, Stacy NI, Crevasse SE, Hernandez JA, Wellehan JFX. USE OF VISCOELASTIC COAGULATION TESTING IN MEGACHIROPTERA ( PTEROPUS HYPOMELANUS AND PTEROPUS VAMPYRUS) REVEALS HIGH VARIABILITY IN CLOT KINETICS. J Zoo Wildl Med 2024; 55:393-403. [PMID: 38875195 DOI: 10.1638/2023-0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2024] [Indexed: 06/16/2024] Open
Abstract
Megachiroptera is a mammalian suborder that includes old world fruit bats. Common clinical problems among captive Megachiroptera, such as liver disease (e.g., iron storage disease), kidney disease (e.g., protein-losing nephropathy), and heart disease (e.g., dilated cardiomyopathy), carry elevated risk for hemostatic derangements. The assessment of viscoelastic coagulation assays, however, has not yet been reported in bats. The main objective of the study was to describe viscoelastography data using the Viscoelastic Coagulation Monitor (VCM) Vet in captive large flying foxes (Pteropus vampyrus) (n = 20) and variable flying foxes (Pteropus hypomelanus) (n = 10). Additional objectives were to compare viscoelastic and clotting parameters (1) between healthy P. vampyrus and P. hypomelanus bats and (2) between untreated bats and those treated with meloxicam or aspirin, and (3) to examine relationships between activated partial thromboplastin time (aPTT) and potentially homologous viscoelastic parameters clotting time (CT) and clot formation time (CFT). The results showed marked variability among clinically normal bats. The intrinsic pathway, as measured by aPTT, had prolonged times compared with most terrestrial mammals, but similar times to birds, marine mammals, and sea turtles. A search of P. vampyrus genome found stop codons present in two exons of the factor XI gene; alterations in factor XI expression would be expected to alter intrinsic coagulation. Because of the high variability, no statistically significant findings were noted in the secondary objectives. Correlation between aPTT and CT or CFT was not strong (rs = 0.406 or 0.192, respectively). The results from this study suggest that clot kinetics vary widely among Megachiroptera when using the VCM Vet with untreated blood. A prolonged intrinsic coagulation pathway, as has been found in other megachiropteran species, and activation of the extrinsic coagulation pathway during venipuncture may be responsible for the inconsistent results.
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Affiliation(s)
- Emily E Brenner
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA,
| | - Amy B Alexander
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
| | - Leonel A Londoño
- Department of Small Animal Clinical Sciences, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
| | - Nicole I Stacy
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
| | - Sarah E Crevasse
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
| | - Jorge A Hernandez
- Department of Large Animal Clinical Sciences, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
| | - James F X Wellehan
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, College of Veterinary Medicine, Gainesville, FL 32610-0126, USA
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2
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Ali AE, Becker RC. The foundation for investigating factor XI as a target for inhibition in human cardiovascular disease. J Thromb Thrombolysis 2024:10.1007/s11239-024-02985-0. [PMID: 38662114 DOI: 10.1007/s11239-024-02985-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2024] [Indexed: 04/26/2024]
Abstract
Anticoagulant therapy is a mainstay in the management of patients with cardiovascular disease and related conditions characterized by a heightened risk for thrombosis. Acute coronary syndrome, chronic coronary syndrome, ischemic stroke, and atrial fibrillation are the most common. In addition to their proclivity for thrombosis, each of these four conditions is also characterized by local and systemic inflammation, endothelial/endocardial injury and dysfunction, oxidative stress, impaired tissue-level reparative capabilities, and immune dysregulation that plays a critical role in linking molecular events, environmental triggers, and phenotypic expressions. Knowing that cardiovascular disease and thrombosis are complex and dynamic, can the scientific community identify a common pathway or specific point of interface susceptible to pharmacological inhibition or alteration that is likely to be safe and effective? The contact factors of coagulation may represent the proverbial "sweet spot" and are worthy of investigation. The following review provides a summary of the fundamental biochemistry of factor XI, its biological activity in thrombosis, inflammation, and angiogenesis, new targeting drugs, and a pragmatic approach to managing hemostatic requirements in clinical trials and possibly day-to-day patient care in the future.
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Affiliation(s)
- Ahmed E Ali
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Richard C Becker
- Department of Internal Medicine, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA.
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3
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He X, Zhang J, Du Y, Liu X, Hu D, Cao B, Gao H, Wu Y, Zhou T, Wu Q, Huang Q, Yang C, Liao C, Zhang L, Shen C, Wang L. BJTJ-1837, a novel FXI activation-blocking antibody. Res Pract Thromb Haemost 2023; 7:100067. [PMID: 36936858 PMCID: PMC10017418 DOI: 10.1016/j.rpth.2023.100067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 12/22/2022] [Accepted: 01/02/2023] [Indexed: 02/10/2023] Open
Abstract
Background Factor (F)XI contributes to thrombosis development while it plays a limited role in normal hemostasis. FXI targeting has the potential for preventing and treating thrombosis with little bleeding risk. Objectives The aim of this study was to develop novel antibody therapeutics against FXI for the treatment of thrombosis-related diseases. Methods Mouse hybridoma technology was applied to screen for anti-FXI antibodies. Surface plasma resonance, enzyme inhibition, activated partial thromboplastin time, and prothrombin time assays were conducted to characterize the binding affinity and activity of antibodies. A cynomolgus monkey arterial venous shunt model was applied to validate the antithrombotic activities. Results A humanized antibody, BJTJ-1837, reported here bound to the protease domain of FXI and activated FXI with high affinity. BJTJ-1837 fully inhibited the activation of FXI by activated FXII and thrombin. BJTJ-1837 also demonstrated strong anticoagulant activity in human and cynomolgus monkey plasma as measured by activated partial thromboplastin time. Moreover, BJTJ-1837 showed favorable antithrombotic activity with a dose-dependent protection in an arterial venous shunt thrombosis model in cynomolgus monkeys without the bleeding adverse effect. Furthermore, BJTJ-1837 displayed favorable pharmacokinetic and pharmacodynamic properties and good developability. Conclusion As a potential antithrombotic therapeutic agent with a safe profile, BJTJ-1837 is a very promising FXI activation-blocking antibody candidate.
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Affiliation(s)
- Xugang He
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Jin Zhang
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Yanping Du
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Xiao Liu
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Dongmei Hu
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Baohua Cao
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Hong Gao
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Yongguang Wu
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
| | - Tianlin Zhou
- Jiangsu Hengrui Pharmaceuticals Co Ltd, Lianyungang, Jiangsu, China
| | - Qimei Wu
- Jiangsu Hengrui Pharmaceuticals Co Ltd, Lianyungang, Jiangsu, China
| | - Qi Huang
- Jiangsu Hengrui Pharmaceuticals Co Ltd, Lianyungang, Jiangsu, China
| | - Changyong Yang
- Jiangsu Hengrui Pharmaceuticals Co Ltd, Lianyungang, Jiangsu, China
| | - Cheng Liao
- Jiangsu Hengrui Pharmaceuticals Co Ltd, Lianyungang, Jiangsu, China
| | - Lianshan Zhang
- Shanghai Hengrui Pharmaceutical Co Ltd, Shanghai, China
- Correspondence Lianshan Zhang, Shanghai Hengrui Pharmaceutical Co Ltd, 279 Wenjing Road, Shanghai 200245, China.
| | - Chenxi Shen
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
- Chenxi Shen and Lei Wang, Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China, Level 7, Building 4, No.9 Yi Ke Road, ZGC Life Science Park, Changping District, Beijing, 102206, China.
| | - Lei Wang
- Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China
- Chenxi Shen and Lei Wang, Beijing TUO JIE Biopharmaceutical Co Ltd, Beijing, China, Level 7, Building 4, No.9 Yi Ke Road, ZGC Life Science Park, Changping District, Beijing, 102206, China.
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4
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Bar Barroeta A, Marquart JA, Bakhtiari K, Meijer AB, Urbanus RT, Meijers JCM. Nanobodies against factor XI apple 3 domain inhibit binding of factor IX and reveal a novel binding site for high molecular weight kininogen. J Thromb Haemost 2022; 20:2538-2549. [PMID: 35815349 PMCID: PMC9795894 DOI: 10.1111/jth.15815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/21/2022] [Accepted: 07/05/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Factor XI (FXI) is a promising target for novel anticoagulants because it shows a strong relation to thromboembolic diseases, while fulfilling a mostly supportive role in hemostasis. Anticoagulants targeting FXI could therefore reduce the risk for thrombosis, without increasing the chance of bleeding side effects. OBJECTIVES To generate nanobodies that can interfere with FXIa mediated activation of factor IX (FIX). METHODS Nanobodies were selected for binding to the apple 3 domain of FXI and their effects on FXI and coagulation were measured in purified protein systems as well as in plasma-based coagulation assays. Additionally, the binding epitope of selected nanobodies was assessed by hydrogen-deuterium exchange mass spectrometry. RESULTS We have identified five nanobodies that inhibit FIX activation by FXI by competing with the FIX binding site on FXI. Interestingly, a sixth nanobody was found to target a different binding epitope in the apple 3 domain, resulting in competition with the FXI-high molecular weight kininogen (HK) interaction. CONCLUSIONS We have characterized a nanobody targeting the FXI apple 3 domain that elucidates the binding orientation of HK on FXI. Moreover, we have produced five nanobodies that can inhibit the FXI-FIX interaction.
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Affiliation(s)
| | | | - Kamran Bakhtiari
- Department of Molecular HematologySanquinAmsterdamthe Netherlands
| | - Alexander B. Meijer
- Department of Molecular HematologySanquinAmsterdamthe Netherlands
- Department of PharmaceuticsUtrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht UniversityUtrechtthe Netherlands
| | - Rolf T. Urbanus
- Center for Benign Haematology, Thrombosis and Haemostasis, Van CreveldkliniekUniversity Medical Center Utrecht, University UtrechtUtrechtthe Netherlands
| | - Joost C. M. Meijers
- Department of Molecular HematologySanquinAmsterdamthe Netherlands
- Department of Experimental Vascular MedicineAmsterdam UMC, University of AmsterdamAmsterdamthe Netherlands
- Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and ThrombosisAmsterdamthe Netherlands
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5
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Choxi R, Kapoor K, Mackman N, Jovin IS. Direct Oral Anticoagulants and Coronary Artery Disease. Arterioscler Thromb Vasc Biol 2022; 42:553-564. [PMID: 35296151 DOI: 10.1161/atvbaha.121.317171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Coronary artery disease is a leading cause of morbidity and mortality worldwide. Acute coronary syndrome as a first presentation is common and patients with established disease have a high rate of recurrent ischemic events, despite antiplatelet therapy. Over the past several years, direct oral anticoagulants have become available and have been studied in patients with coronary artery disease. These medications directly inhibit either thrombin or factor Xa which contribute to atherothrombosis. This review will summarize the clinical data regarding the use of direct oral anticoagulants in different patient populations with coronary disease and the balance between protection against ischemia and bleeding. Additionally, the review will summarize the available data on the use of direct oral anticoagulants periprocedurally in patients undergoing percutaneous coronary intervention. The future direction of coronary artery disease and the role of direct oral anticoagulants will rely on further studies determining the optimal combination of antiplatelet and oral anticoagulant regimens that derive ischemic benefit without increased rates of bleeding. Additional upstream blockade of the coagulation cascade with factor XIIa and factor XIa inhibitors may also improve treatment in the future.
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Affiliation(s)
- Ravi Choxi
- Department of Medicine, Virginia Commonwealth University, Richmond (R.C., K.K., I.S.J.)
| | - Kunal Kapoor
- Department of Medicine, Virginia Commonwealth University, Richmond (R.C., K.K., I.S.J.)
| | - Nigel Mackman
- UNC Blood Research Center, Department of Medicine, University of North Carolina at Chapel Hill (N.M.)
| | - Ion S Jovin
- Department of Medicine, Virginia Commonwealth University, Richmond (R.C., K.K., I.S.J.).,McGuire Veterans Administration Medical Center Richmond, VA (I.S.J.)
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6
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Bianchini EP, Razanakolona M, Helms J, Zouiti F, Couteau-Chardon A, Marin-Esteban V, Chaisemartin LD, De-Carvalho A, Bironien R, Chollet-Martin S, Denis CV, Diehl JL, Vasse M, Meziani F, Borgel D. The Proteolytic Inactivation of Protein Z-Dependent Protease Inhibitor by Neutrophil Elastase Might Promote the Procoagulant Activity of Neutrophil Extracellular Traps in Sepsis. Thromb Haemost 2022; 122:506-516. [PMID: 34134169 DOI: 10.1055/a-1530-3980] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Septic shock is the archetypal clinical setting in which extensive crosstalk between inflammation and coagulation dysregulates the latter. The main anticoagulant systems are systematically impaired, depleted, and/or downregulated. Protein Z-dependent protease inhibitor (ZPI) is an anticoagulant serpin that not only targets coagulation factors Xa and XIa but also acts as an acute phase reactant whose plasma concentration rises in inflammatory settings. The objective of the present study was to assess the plasma ZPI antigen level in a cohort of patients suffering from septic shock with or without overt-disseminated intravascular coagulation (DIC). The plasma ZPI antigen level was approximately 2.5-fold higher in the patient group (n = 100; 38 with DIC and 62 without) than in healthy controls (n = 31). The elevation's magnitude did not appear to depend on the presence/absence of DIC. Furthermore, Western blots revealed the presence of cleaved ZPI in plasma from patients with severe sepsis, independently of the DIC status. In vitro, ZPI was proteolytically inactivated by purified neutrophil elastase (NE) and by NE on the surface of neutrophil extracellular traps (NETs). The electrophoretic pattern of ZPI after NE-catalyzed proteolysis was very similar to that resulting from the clotting process-suggesting that the cleaved ZPI observed in severe sepsis plasma is devoid of anticoagulant activity. Taken as a whole, our results (1) suggest that NE is involved in ZPI inactivation during sepsis, and (2) reveal a novel putative mechanism for the procoagulant activity of NETs in immunothrombosis.
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Affiliation(s)
- Elsa P Bianchini
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Mahita Razanakolona
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Julie Helms
- Service de Médecine Intensive-Réanimation, Nouvel Hôpital Civil, Hôpitaux universitaires de Strasbourg, Faculté de Médecine, Université de Strasbourg, Strasbourg, France.,UMR_S1109, Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine, Fédération Hospitalo-Universitaire, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Fouzia Zouiti
- Service d'Hématologie biologique, Hôpital Antoine Béclère, APHP, Université Paris-Saclay, Clamart, France
| | - Amélie Couteau-Chardon
- Service de Médecine Intensive-Réanimation, Hôpital Européen Georges Pompidou, APHP, Paris, France
| | - Viviana Marin-Esteban
- UMR_996, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Chatenay-Malabry, France
| | - Luc de Chaisemartin
- UMR_996, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Chatenay-Malabry, France.,Laboratoire d'Immunologie, Hôpital Bichat, APHP, Paris, France
| | - Allan De-Carvalho
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | | | - Sylvie Chollet-Martin
- UMR_996, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Chatenay-Malabry, France.,Laboratoire d'Immunologie, Hôpital Bichat, APHP, Paris, France
| | - Cécile V Denis
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Jean-Luc Diehl
- Service de Médecine Intensive-Réanimation, Hôpital Européen Georges Pompidou, APHP, Paris, France.,UMR_S1140, Institut National de la Santé et de la Recherche Médicale, Université de Paris, Paris, France
| | - Marc Vasse
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,Service de Biologie Clinique, Hôpital Foch, Suresnes, France
| | - Ferhat Meziani
- Service de Médecine Intensive-Réanimation, Nouvel Hôpital Civil, Hôpitaux universitaires de Strasbourg, Faculté de Médecine, Université de Strasbourg, Strasbourg, France.,UMR_1260, Institut National de la Santé et de la Recherche Médicale, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - Delphine Borgel
- HITh, UMR_S1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,Laboratoire d'Hématologie Biologique, Hôpital Necker, APHP, Paris, France
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7
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A FRET-based assay for the quantitation of the thrombin-factor XI interaction. Thromb Res 2022; 214:23-28. [DOI: 10.1016/j.thromres.2022.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/30/2022] [Accepted: 04/11/2022] [Indexed: 11/23/2022]
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8
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Eikelboom J, Floege J, Thadhani R, Weitz JI, Winkelmayer WC. Anticoagulation in patients with kidney failure on dialysis: factor XI as a therapeutic target. Kidney Int 2021; 100:1199-1207. [PMID: 34600964 DOI: 10.1016/j.kint.2021.08.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 12/18/2022]
Abstract
Chronic kidney disease is present in almost 10% of the world population and is associated with excess mortality and morbidity. Reduced glomerular filtration rate and the presence and extent of proteinuria, key domains of chronic kidney disease, have both been shown to be strong and independent risk factors for cardiovascular disease. Patients with kidney failure requiring dialysis are at highest risk for cardiovascular events (e.g., stroke or myocardial infarction), and of developing chronic cardiovascular conditions, such as heart failure. Despite the high burden of cardiovascular disease, there is a paucity of evidence supporting therapies to reduce this risk. Although long-term anticoagulant treatment has the potential to prevent thromboembolism in persons with kidney failure on dialysis, this possibility remains understudied. The limited data available on anticoagulation in patients with kidney failure has focused on vitamin K antagonists or direct oral anticoagulants that inhibit thrombin or factor (F) Xa. The risk of bleeding is a major concern with these agents. However, FXI is emerging as a potential safer target for new anticoagulants because FXI plays a greater part in thrombosis than in hemostasis. In this article, we (i) explain the rationale for considering anticoagulation therapy in patients with kidney failure to reduce atherothrombotic events, (ii) highlight the limitations of current anticoagulants in this patient population, (iii) explain the potential benefits of FXI inhibitors, and (iv) summarize ongoing studies investigating FXI inhibition in patients with kidney failure on dialysis.
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Affiliation(s)
- John Eikelboom
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jürgen Floege
- Department of Nephrology, RWTH University of Aachen, Aachen, Germany
| | - Ravi Thadhani
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jeffrey I Weitz
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada; Thrombosis and Atherosclerosis Research Institute, Hamilton General Hospital, Hamilton, Ontario, Canada
| | - Wolfgang C Winkelmayer
- Department of Medicine, Section of Nephrology and Selzman Institute for Kidney Health, Baylor College of Medicine, Houston, Texas, USA.
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9
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Abstract
Factor XI (FXI) deficiency (hemophilia C or Rosenthal disease) was first described in the 1950s in a multigenerational family experiencing bleeding related to surgery and dental procedures. Managing patients with FXI deficiency presents several challenges, including a lack of correlation of bleeding symptoms with FXI activity levels, the large volume of fresh frozen plasma required to achieve hemostatic FXI levels, lack of availability of FXI concentrate in certain regions of the world, and the inherent thrombotic risk associated with replacement therapy. This article summarizes presentation, diagnosis, and management of patients with FXI deficiency in a variety of clinical settings.
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Affiliation(s)
| | - Jean Marie Connors
- Hematology Division, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, 75 Francis Street, Boston, MA 02215, USA. https://twitter.com/connors_md
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10
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Nguyen PC, Stevens H, Peter K, McFadyen JD. Submassive Pulmonary Embolism: Current Perspectives and Future Directions. J Clin Med 2021; 10:jcm10153383. [PMID: 34362166 PMCID: PMC8347177 DOI: 10.3390/jcm10153383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/22/2022] Open
Abstract
Submassive pulmonary embolism (PE) lies on a spectrum of disease severity between standard and high-risk disease. By definition, patients with submassive PE have a worse outcome than the majority of those with standard-risk PE, who are hemodynamically stable and lack imaging or laboratory features of cardiac dysfunction. Systemic thrombolytic therapy has been proven to reduce mortality in patients with high-risk disease; however, its use in submassive PE has not demonstrated a clear benefit, with haemodynamic improvements being offset by excess bleeding. Furthermore, meta-analyses have been confusing, with conflicting results on overall survival and net gain. As such, significant interest remains in optimising thrombolysis, with recent efforts in catheter-based delivery as well as upcoming studies on reduced systemic dosing. Recently, long-term cardiorespiratory limitations following submassive PE have been described, termed post-PE syndrome. Studies on the ability of thrombolytic therapy to prevent this condition also present conflicting evidence. In this review, we aim to clarify the current evidence with respect to submassive PE management, and also to highlight shortcomings in current definitions and prognostic factors. Additionally, we discuss novel therapies currently in preclinical and early clinical trials that may improve outcomes in patients with submassive PE.
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Affiliation(s)
- Phillip C. Nguyen
- Department of Haematology, Alfred Hospital, Melbourne, VIC 3181, Australia; (P.C.N.); (H.S.)
| | - Hannah Stevens
- Department of Haematology, Alfred Hospital, Melbourne, VIC 3181, Australia; (P.C.N.); (H.S.)
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia;
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia;
- Department of Medicine, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Cardiology, The Alfred Hospital, Melbourne, VIC 3181, Australia
| | - James D. McFadyen
- Department of Haematology, Alfred Hospital, Melbourne, VIC 3181, Australia; (P.C.N.); (H.S.)
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia;
- Department of Medicine, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Melbourne, VIC 3010, Australia
- Correspondence: ; Tel.: +61-3-9076-2179
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11
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Zwart B, Parker WAE, Storey RF. New Antithrombotic Drugs in Acute Coronary Syndrome. J Clin Med 2020; 9:E2059. [PMID: 32629976 PMCID: PMC7408919 DOI: 10.3390/jcm9072059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 12/15/2022] Open
Abstract
In recent years, much progress has been made in the field of antithrombotic drugs in acute coronary syndrome (ACS) treatment, as reflected by the introduction of the more potent P2Y12-inhibitors prasugrel and ticagrelor, and novel forms of concomitant anticoagulation, such as fondaparinux and bivalirudin. However, despite substantial improvements in contemporary ACS treatment, there remains residual ischemic risk in this group and hence the need for even more effective antithrombotic drugs, while balancing antithrombotic efficacy against bleeding risk. This review discusses recently introduced and currently developed antiplatelet and anticoagulant drugs in ACS treatment.
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Affiliation(s)
- Bastiaan Zwart
- Department of Cardiology, St. Antonius Hospital, 3435 CM Nieuwegein, The Netherlands
- Department of Cardiology, Catharina Hospital, 5623 EJ Eindhoven, The Netherlands
| | - William A. E. Parker
- Cardiovascular Research Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2RX, UK; (W.A.E.P.); (R.F.S.)
- South Yorkshire Cardiothoracic Centre, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S5 7AU, UK
| | - Robert F. Storey
- Cardiovascular Research Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2RX, UK; (W.A.E.P.); (R.F.S.)
- South Yorkshire Cardiothoracic Centre, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S5 7AU, UK
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12
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Novel antithrombotic strategies for treatment of venous thromboembolism. Blood 2020; 135:351-359. [PMID: 31917385 DOI: 10.1182/blood.2019000919] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 12/16/2019] [Indexed: 12/25/2022] Open
Abstract
Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most common cause of vascular death after heart attack and stroke. Anticoagulation therapy is the cornerstone of VTE treatment. Despite such therapy, up to 50% of patients with DVT develop postthrombotic syndrome, and up to 4% of patients with PE develop chronic thromboembolic pulmonary hypertension. Therefore, better therapies are needed. Although direct oral anticoagulants are more convenient and safer than warfarin for VTE treatment, bleeding remains the major side effect, particularly in cancer patients. Factor XII and factor XI have emerged as targets for new anticoagulants that may be safer. To reduce the complications of VTE, attenuation of thrombin activatable fibrinolysis inhibitor activity is under investigation in PE patients to enhance endogenous fibrinolysis, whereas blockade of leukocyte interaction with the vessel wall is being studied to reduce the inflammation that contributes to postthrombotic syndrome in DVT patients. Focusing on these novel antithrombotic strategies, this article explains why safer anticoagulants are needed, provides the rationale for factor XII and XI as targets for such agents, reviews the data on the factor XII- and factor XI-directed anticoagulants under development, describes novel therapies to enhance fibrinolysis and decrease inflammation in PE and DVT patients, respectively, and offers insights into the opportunities for these novel VTE therapies.
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13
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Abstract
Recent advances in our understanding of the contribution of thrombin generation to arterial thrombosis and the role of platelets in venous thrombosis have prompted new treatment paradigms. Nonetheless, bleeding remains the major side effect of such treatments spurring the quest for new antithrombotic regimens with better benefit-risk profiles and for safer anticoagulants for existing and new indications. The aims of this article are to review the results of recent trials aimed at enhancing the benefit-risk profile of antithrombotic therapy and explain how these findings are changing our approach to the management of arterial and venous thrombosis. Focusing on these 2 aspects of thrombosis management, this article discusses 4 advances: (1) the observation that in some indications, lowering the dose of some direct oral anticoagulants reduces the risk of bleeding without compromising efficacy, (2) the recognition that aspirin is not only effective for secondary prevention of atherothrombosis but also for prevention of venous thromboembolism, (3) the finding that dual pathway inhibition with the combination of low-dose rivaroxaban to attenuate thrombin generation plus aspirin to reduce thromboxane A2-mediated platelet activation is superior to aspirin or rivaroxaban alone for prevention of atherothrombosis in patients with coronary or peripheral artery disease, and (4) the development of inhibitors of factor XI or XII as potentially safer anticoagulants.
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Affiliation(s)
- Noel C Chan
- From the Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jeffrey I Weitz
- From the Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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14
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Székely O, Borgi M, Lip GYH. Factor XI inhibition fulfilling the optimal expectations for ideal anticoagulation. Expert Opin Emerg Drugs 2019; 24:55-61. [DOI: 10.1080/14728214.2019.1591368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Orsolya Székely
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Marco Borgi
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Gregory Y. H. Lip
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, UK
- Aalborg Thrombosis Research Unit, Aalborg University, Aalborg, Denmark
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15
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Abstract
PURPOSE OF REVIEW The last 40 years of clinical research in interventional cardiology were extraordinarily innovative. This article will review the most promising up and coming interventional cardiovascular therapies, with a primary focus on the treatment of coronary artery disease. RECENT FINDINGS From the first stent, to the first transcatheter aortic valve implantation (TAVI), and the left appendage closure technique, percutaneous interventions revolutionized the treatment of multiple diseases and dramatically improved the prognosis of many patients. While these advances have decreased the risk of mortality in some patients (such as ST-elevation myocardial infarction), 15% of acute coronary syndrome (ACS) patients still experience recurrent ischemic events within the first year, challenging us to develop new pharmaceutical targets and new devices. The continued emergence of data supporting inflammation as a risk factor and pharmacologic target as well as data supporting the importance of cholesterol efflux have identified novel therapeutic targets that may play a major role in the improvement of prognosis of patients with coronary artery disease. In addition, novel medical devices are being developed to allow even earlier detection of acute cardiac events and to support high-risk percutaneous coronary interventions. Advances in computing and the ability to analyze large datasets will allow us to use artificial intelligence to augment the clinician patient experience, both in and out of the catheterization laboratory, with live procedural guidance as well as pre- and post-operative prognostication tools.
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16
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Abstract
Thrombosis remains a major cause of morbidity and mortality. Consequently, advances in antithrombotic therapy are needed to reduce the disease burden. This article focuses on 2 such advances. First, the prevention of atherothrombosis in patients with coronary or peripheral artery disease, which has been enhanced by the finding that the combination of low-dose rivaroxaban plus aspirin is superior to aspirin alone for prevention of recurrent ischemic events. However, this benefit comes at the cost of increased bleeding albeit not fatal bleeding. To overcome this problem, the second advance is the identification of factor XI as a target for new anticoagulants that are potentially safer than those currently available.
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Affiliation(s)
- Jeffrey I. Weitz
- From the Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Noel C. Chan
- From the Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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17
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Székely O, Miyazawa K, Lip GYH. Current and emerging pharmacotherapy for ischemic stroke prevention in patients with atrial fibrillation. Expert Opin Pharmacother 2018; 19:1999-2009. [PMID: 30359142 DOI: 10.1080/14656566.2018.1537368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Introduction: Atrial fibrillation (AF) is associated with high morbidity and mortality rates due to thromboembolic complications, and anticoagulation is central to the management of this common arrhythmia to prevent acute thromboembolic events. The traditional anticoagulants: heparin, fondaparinux, and vitamin K antagonists (VKA, e.g. warfarin, acenocoumarol or phenprocoumin) have long served as pharmacotherapy for ischemic stroke prophylaxis. Areas covered: In this review article, the authors provide an overview on current and emerging pharmacotherapy for ischemic stroke prevention. Furthermore, they review the data from novel therapeutic targets in the coagulation cascade, and investigational anticoagulant drugs currently assessed in preclinical and clinical studies. Expert opinion: The introduction of nonvitamin K antagonist oral anticoagulants (NOACs) was an important milestone, as these drugs show relative efficacy, safety, and convenience compared to the VKAs. Nevertheless, their clinical use still has some limitations with, for example, patients with severe renal impairment and those with mechanical heart valves, high bleeding risks, lack of standard laboratory monitoring and (some) reversal agents. To overcome some of these limitations, various attempts are now underway to discover new strategies and targets via the hemostatic pathway in order to develop new coagulation inhibiting drugs.
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Affiliation(s)
- Orsolya Székely
- a Institute of Cardiovascular Sciences , University of Birmingham , Birmingham , UK
| | - Kazuo Miyazawa
- a Institute of Cardiovascular Sciences , University of Birmingham , Birmingham , UK
| | - Gregory Yoke Hong Lip
- a Institute of Cardiovascular Sciences , University of Birmingham , Birmingham , UK.,b Liverpool Centre for Cardiovascular Science , University of Liverpool and Liverpool Heart & Chest Hospital , Liverpool , UK.,c Aalborg Thrombosis Research Unit , Aalborg University , Aalborg , Denmark
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18
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Abstract
Pulmonary embolism (PE) is caused by emboli, which have originated from venous thrombi, travelling to and occluding the arteries of the lung. PE is the most dangerous form of venous thromboembolism, and undiagnosed or untreated PE can be fatal. Acute PE is associated with right ventricular dysfunction, which can lead to arrhythmia, haemodynamic collapse and shock. Furthermore, individuals who survive PE can develop post-PE syndrome, which is characterized by chronic thrombotic remains in the pulmonary arteries, persistent right ventricular dysfunction, decreased quality of life and/or chronic functional limitations. Several important improvements have been made in the diagnostic and therapeutic management of acute PE in recent years, such as the introduction of a simplified diagnostic algorithm for suspected PE as well as phase III trials demonstrating the value of direct oral anticoagulants in acute and extended treatment of venous thromboembolism. Future research should aim to address novel treatment options (for example, fibrinolysis enhancers) and improved methods for predicting long-term complications and defining optimal anticoagulant therapy parameters in individual patients, and to gain a greater understanding of post-PE syndrome.
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Plow EF, Wang Y, Simon DI. The search for new antithrombotic mechanisms and therapies that may spare hemostasis. Blood 2018; 131:1899-1902. [PMID: 29467183 PMCID: PMC5921961 DOI: 10.1182/blood-2017-10-784074] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/13/2018] [Indexed: 12/20/2022] Open
Abstract
Current antithrombotic drugs, including widely used antiplatelet agents and anticoagulants, are associated with significant bleeding risk. Emerging experimental evidence suggests that the molecular and cellular mechanisms of hemostasis and thrombosis can be separated, thereby increasing the possibility of new antithrombotic therapeutic targets with reduced bleeding risk. We review new coagulation and platelet targets and highlight the interaction between integrin αMβ2 (Mac-1, CD11b/CD18) on leukocytes and GPIbα on platelets that seems to distinguish thrombosis from hemostasis.
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Affiliation(s)
| | - Yunmei Wang
- Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Case Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Daniel I Simon
- Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Case Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, OH
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20
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Weitz JI, Fredenburgh JC. 2017 Scientific Sessions Sol Sherry Distinguished Lecture in Thrombosis. Arterioscler Thromb Vasc Biol 2018; 38:304-310. [DOI: 10.1161/atvbaha.117.309664] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/05/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Jeffrey I. Weitz
- From the Department of Medicine (J.I.W., J.C.F.) and Department of Biochemistry and Biomedical Sciences (J.I.W.), McMaster University, Hamilton, Ontario, Canada; and Thrombosis and Atherosclerosis Research Institute (J.I.W., J.C.F.), Hamilton, Ontario, Canada
| | - James C. Fredenburgh
- From the Department of Medicine (J.I.W., J.C.F.) and Department of Biochemistry and Biomedical Sciences (J.I.W.), McMaster University, Hamilton, Ontario, Canada; and Thrombosis and Atherosclerosis Research Institute (J.I.W., J.C.F.), Hamilton, Ontario, Canada
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21
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Dimitropoulos G, Rahim SMZ, Moss AS, Lip GYH. New anticoagulants for venous thromboembolism and atrial fibrillation: what the future holds. Expert Opin Investig Drugs 2017; 27:71-86. [DOI: 10.1080/13543784.2018.1416090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Gerasimos Dimitropoulos
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - S. M. Zubair Rahim
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - Alexandra Sophie Moss
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - Gregory Y. H. Lip
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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22
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Fischer PM. Design of Small-Molecule Active-Site Inhibitors of the S1A Family Proteases as Procoagulant and Anticoagulant Drugs. J Med Chem 2017; 61:3799-3822. [DOI: 10.1021/acs.jmedchem.7b00772] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Peter M. Fischer
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K
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23
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Ay C, Hisada Y, Cooley BC, Mackman N. Factor XI-deficient mice exhibit increased bleeding after injury to the saphenous vein. J Thromb Haemost 2017; 15:1829-1833. [PMID: 28677246 DOI: 10.1111/jth.13766] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Indexed: 11/28/2022]
Abstract
Essentials Factor XI (FXI) deficient mice have normal hemostasis in a tail transection model. The hemostatic capacity of FXI-/- mice was assessed in three different bleeding models. FXI-/- mice have increased saphenous vein bleeding. FXI-/- mice may be a useful experimental model to study bleeding associated with FXI deficiency. SUMMARY Background Factor XI (FXI) is a key component of the intrinsic pathway of coagulation. It can be activated by either FXIIa or thrombin and amplifies thrombin generation during clot formation. Congenital FXI deficiency in humans (known as hemophilia C) is associated with bleeding after hemostatic challenge. However, to date there are no reports of excess bleeding in FXI-deficient mice. Objectives To determine if the absence of FXI in mice prolongs bleeding in different models. Methods We assessed the hemostatic capacity of FXI-/- mice in three different bleeding models: tail bleeding, surgical bleeding and saphenous vein bleeding. Results We found that tail bleeding and surgical bleeding of FXI-/- mice were similar to wild-type mice. However, FXI-/- mice had an impaired hemostatic capacity in the saphenous vein bleeding model compared with wild-type controls. Conclusions Our results indicate that FXI-/- mice have a mild hemostatic defect after injury to the saphenous vein but not after transection of the tail or vessels in the abdominal wall.
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Affiliation(s)
- C Ay
- Department of Medicine, Division of Hematology and Oncology, Thrombosis and Hemostasis Program, UNC McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Clinical Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Y Hisada
- Department of Medicine, Division of Hematology and Oncology, Thrombosis and Hemostasis Program, UNC McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- K.G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, Tromsø, Norway
| | - B C Cooley
- Department of Pathology and Laboratory Medicine, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - N Mackman
- Department of Medicine, Division of Hematology and Oncology, Thrombosis and Hemostasis Program, UNC McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- K.G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, Tromsø, Norway
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24
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Donkor DA, Bhakta V, Eltringham-Smith LJ, Stafford AR, Weitz JI, Sheffield WP. Selection and characterization of a DNA aptamer inhibiting coagulation factor XIa. Sci Rep 2017; 7:2102. [PMID: 28522812 PMCID: PMC5437010 DOI: 10.1038/s41598-017-02055-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 04/05/2017] [Indexed: 12/26/2022] Open
Abstract
Factor XIa (FXIa) is a serine protease that catalyzes the activation of Factor IX (FIX) in the blood coagulation cascade. FXIa and its precursor FXI are emergent therapeutic targets for the development of safer anticoagulant agents. Here, we sought a novel DNA-based agent to inhibit FXIa. Towards this goal, an 80 base, single-stranded DNA aptamer library (containing a 40 base randomized core) was screened for FXIa-binding candidates, using ten rounds of positive and negative selection. After selection, 6 of 89 different sequences inhibited FXIa-mediated chromogenic substrate S2366 cleavage. The most active anti-FXIa aptamer had a hypervariable central sequence 5′-AACCTATCGGACTATTGTTAGTGATTTTTATAGTGT-3′ and was designated Factor ELeven Inhibitory APtamer (FELIAP). FELIAP, but not a scrambled aptamer control (SCRAPT), competitively inhibited FXIa-catalyzed S2366 cleavage, FIX activation, and complex formation with antithrombin. No effect of FELIAP on FXI activation was observed. FELIAP inhibited plasma clotting and thrombin generation assays to a significantly greater extent than SCRAPT. Immobilized FELIAP bound FXIa with strong affinity and an equilibrium binding constant (KD) in the low nanomolar range determined using surface plasmon resonance. FELIAP is the first FXIa-inhibitory aptamer to be described and constitutes a lead compound to develop related aptamers for in vivo use.
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Affiliation(s)
- David A Donkor
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Varsha Bhakta
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada
| | | | - Alan R Stafford
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
| | - Jeffrey I Weitz
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
| | - William P Sheffield
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada. .,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
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25
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Abstract
Although the non-vitamin antagonist oral anticoagulants produce less intracranial bleeding than warfarin, serious bleeding still occurs. Therefore, the search for safer anticoagulants continues. Factor XII and factor XI have emerged as promising targets whose inhibition has the potential to prevent thrombosis with little or no disruption of hemostasis. Thus, thrombosis is attenuated in mice deficient in factor XII or factor XI and patients with congenital factor XII deficiency do not bleed and those with factor XI deficiency rarely have spontaneous bleeding. Strategies targeting factor XII and XI include antisense oligonucleotides to decrease their synthesis, inhibitory antibodies or aptamers, and small molecule inhibitors. These strategies attenuate thrombosis in various animal models and factor XI knockdown with an antisense oligonucleotide in patients undergoing knee replacement surgery reduced postoperative venous thromboembolism to a greater extent than enoxaparin without increasing bleeding. Therefore, current efforts are focused on evaluating the efficacy and safety of factor XII and factor XI directed anticoagulant strategies.
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Affiliation(s)
- Jeffrey I Weitz
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada; Thrombosis and Atherosclerosis Research Institute, Hamilton, Canada.
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26
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Weitz JI, Fredenburgh JC. Factors XI and XII as Targets for New Anticoagulants. Front Med (Lausanne) 2017; 4:19. [PMID: 28286749 PMCID: PMC5323386 DOI: 10.3389/fmed.2017.00019] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/10/2017] [Indexed: 01/01/2023] Open
Abstract
Compared with vitamin K antagonists, the direct oral anticoagulants (DOACs) are simpler to administer and are associated with less intracranial bleeding. Nonetheless, even with the DOACs, bleeding still occurs and many patients with atrial fibrillation fail to receive anticoagulant thromboprophylaxis because of the fear of bleeding. Therefore, there is an urgent need for safer anticoagulants. Recent investigations into the biochemistry of hemostasis and thrombosis have identified new targets for development of novel anticoagulants. Using data from complementary sources, including epidemiological studies and investigations in various animal models, the contact pathway has emerged as a potential mediator of thrombosis that plays a minor part in hemostasis. Consequently, factor (F) XII of the contact system and FXI in the intrinsic pathway have been identified as potentially safer targets of anticoagulation than thrombin or FXa. However, further studies are needed to identify which is the better target for the appropriate indication. This review highlights the evidence for focusing on FXI and FXII and examines the novel approaches directed at these new targets. These emerging strategies should address current unmet medical needs and provide new avenues by which to improve anticoagulant therapy by reducing the risk of bleeding.
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Affiliation(s)
- Jeffrey I. Weitz
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- The Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, ON, Canada
- *Correspondence: Jeffrey I. Weitz,
| | - James C. Fredenburgh
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- The Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, ON, Canada
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27
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Abstract
Despite the introduction of direct oral anticoagulants (DOACs), the search for more effective and safer antithrombotic strategies continues. Better understanding of the pathogenesis of thrombosis has fostered 2 new approaches to achieving this goal. First, evidence that thrombin may be as important as platelets to thrombosis at sites of arterial injury and that platelets contribute to venous thrombosis has prompted trials comparing anticoagulants with aspirin for secondary prevention in arterial thrombosis and aspirin with anticoagulants for primary and secondary prevention of venous thrombosis. These studies will help identify novel treatment strategies. Second, emerging data that naturally occurring polyphosphates activate the contact system and that this system is critical for thrombus stabilization and growth have identified factor XII (FXII) and FXI as targets for new anticoagulants that may be even safer than the DOACs. Studies are needed to determine whether FXI or FXII is the better target and to compare the efficacy and safety of these new strategies with current standards of care for the prevention or treatment of thrombosis. Focusing on these advances, this article outlines how treatment strategies for thrombosis are evolving and describes the rationale and approaches to targeting FXII and FXI. These emerging anticoagulant strategies should address unmet needs and reduce the systemic underuse of anticoagulation because of the fear of bleeding.
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28
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Novel phenylalanine derived diamides as Factor XIa inhibitors. Bioorg Med Chem Lett 2016; 26:472-478. [DOI: 10.1016/j.bmcl.2015.11.089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 12/30/2022]
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29
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Worm M, Köhler EC, Panda R, Long A, Butler LM, Stavrou EX, Nickel KF, Fuchs TA, Renné T. The factor XIIa blocking antibody 3F7: a safe anticoagulant with anti-inflammatory activities. ANNALS OF TRANSLATIONAL MEDICINE 2015; 3:247. [PMID: 26605293 DOI: 10.3978/j.issn.2305-5839.2015.09.07] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The plasma protein factor XII (FXII) is the initiating protease of the procoagulant and proinflammatory contact system. FXII activates both the bradykinin (BK) producing kallikrein-kinin system and the intrinsic pathway of coagulation. Contact with negatively charged surfaces induces auto-activation of zymogen FXII that results in activated FXII (FXIIa). Various in vivo activators of FXII have been identified including heparin, misfolded protein aggregates, nucleic acids and polyphosphate. Murine models have established a central role of FXII in arterial and venous thromboembolic diseases. Despite the central function of FXII in pathologic thrombosis, its deficiency does not impair hemostasis in animals or humans. The selective role of FXIIa in thrombosis, but not hemostasis, offers an exciting novel strategy for safe anticoagulation based on interference with FXIIa. We have generated the recombinant fully human FXIIa-blocking antibody 3F7, which abolished FXIIa enzymatic activity and prevented thrombosis in a cardiopulmonary bypass system in large animals, in the absence of increased therapy-associated bleeding. Furthermore, 3F7 also interfered with BK-driven edema in the severe swelling disorder hereditary angioedema (HAE) type III. Taken together, targeting FXIIa with 3F7 appears to be a promising approach to treat edema disorders and thrombosis.
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Affiliation(s)
- Marie Worm
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Elodie C Köhler
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Rachita Panda
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Andy Long
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Lynn M Butler
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Evi X Stavrou
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Katrin F Nickel
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Tobias A Fuchs
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
| | - Thomas Renné
- 1 Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ; 2 Division of Clinical Chemistry, Department of Molecular Medicine and Surgery and Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden ; 3 Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA ; 4 Department of Medicine, Louis Stokes Veterans Administration Hospital, Cleveland, Ohio, USA
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30
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Gailani D, Bane CE, Gruber A. Factor XI and contact activation as targets for antithrombotic therapy. J Thromb Haemost 2015; 13:1383-95. [PMID: 25976012 PMCID: PMC4516614 DOI: 10.1111/jth.13005] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/01/2015] [Indexed: 11/26/2022]
Abstract
The most commonly used anticoagulants produce therapeutic antithrombotic effects either by inhibiting thrombin or factor Xa (FXa) or by lowering the plasma levels of the precursors of these key enzymes, prothrombin and FX. These drugs do not distinguish between thrombin generation contributing to thrombosis from thrombin generation required for hemostasis. Thus, anticoagulants increase bleeding risk, and many patients who would benefit from therapy go untreated because of comorbidities that place them at unacceptable risk for hemorrhage. Studies in animals demonstrate that components of the plasma contact activation system contribute to experimentally induced thrombosis, despite playing little or no role in hemostasis. Attention has focused on FXII, the zymogen of a protease (FXIIa) that initiates contact activation when blood is exposed to foreign surfaces, and FXI, the zymogen of the protease FXIa, which links contact activation to the thrombin generation mechanism. In the case of FXI, epidemiologic data indicate this protein contributes to stroke and venous thromboembolism, and perhaps myocardial infarction, in humans. A phase 2 trial showing that reduction of FXI may be more effective than low molecular weight heparin at preventing venous thrombosis during knee replacement surgery provides proof of concept for the premise that an antithrombotic effect can be uncoupled from an anticoagulant effect in humans by targeting components of contact activation. Here, we review data on the role of FXI and FXII in thrombosis and results of preclinical and human trials for therapies targeting these proteins.
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Affiliation(s)
- David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Charles E. Bane
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Andras Gruber
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
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Morrissey JH, Smith SA. Polyphosphate as modulator of hemostasis, thrombosis, and inflammation. J Thromb Haemost 2015; 13 Suppl 1:S92-7. [PMID: 26149055 PMCID: PMC4497372 DOI: 10.1111/jth.12896] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Inorganic polyphosphate (polyP), a linear polymer of phosphates, is present in many infectious microorganisms and is secreted by mast cells and platelets. PolyP has recently been shown to accelerate blood clotting and slow fibrinolysis, in a manner that is highly dependent on polymer length. Very long-chain polyP (of the type present in microorganisms) is an especially potent trigger of the contact pathway, enhances the proinflammatory activity of histones, and may participate in host responses to pathogens. PolyP also inhibits complement, providing another link between polyP and inflammation/innate immunity. Platelet-size polyP (which is considerably shorter) accelerates factor V activation, opposes the anticoagulant action of tissue factor pathway inhibitor, modulates fibrin clot structure, and promotes factor XI activation. PolyP may have utility in treating bleeding. It is also a potential target for the development of antithrombotic drugs with a novel mechanism of action and potentially fewer bleeding side effects compared with conventional anticoagulants.
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Affiliation(s)
- J H Morrissey
- Biochemistry Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - S A Smith
- Biochemistry Department, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Labberton L, Kenne E, Renné T. New agents for thromboprotection. A role for factor XII and XIIa inhibition. Hamostaseologie 2015; 35:338-50. [PMID: 25609114 DOI: 10.5482/hamo-14-11-0060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 01/13/2015] [Indexed: 11/05/2022] Open
Abstract
Blood coagulation is essential for hemostasis, however excessive coagulation can lead to thrombosis. Factor XII starts the intrinsic coagulation pathway and contact-induced factor XII activation provides the mechanistic basis for the diagnostic aPTT clotting assay. Despite its function for fibrin formation in test tubes, patients and animals lacking factor XII have a completely normal hemostasis. The lack of a bleeding tendency observed in factor XII deficiency states is in sharp contrast to deficiencies of other components of the coagulation cascade and factor XII has been considered to have no function for coagulation in vivo. Recently, experimental animal models showed that factor XII is activated by an inorganic polymer, polyphosphate, which is released from procoagulant platelets and that polyphosphate-driven factor XII activation has an essential role in pathologic thrombus formation. Cumulatively, the data suggest to target polyphosphate, factor XII, or its activated form factor XIIa for anticoagulation. As the factor XII pathway specifically contributes to thrombosis but not to hemostasis, interference with this pathway provides a unique opportunity for safe anticoagulation that is not associated with excess bleeding. The review summarizes current knowledge on factor XII functions, activators and inhibitors.
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Affiliation(s)
| | | | - T Renné
- Thomas Renné, M.D. Ph.D., Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital Solna (L2:05), 171 76 Stockholm, Sweden, Tel. +46/8/51 77 33 90, +49/(0)40/741 05 89 84, Fax +46/31 03 76, +49/(0)40/741 05 75 76, E-mail:
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Argade MD, Mehta AY, Sarkar A, Desai UR. Allosteric inhibition of human factor XIa: discovery of monosulfated benzofurans as a class of promising inhibitors. J Med Chem 2014; 57:3559-69. [PMID: 24666186 PMCID: PMC4317055 DOI: 10.1021/jm5002698] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Factor
XIa (fXIa) is being recognized as a prime target for developing
safer anticoagulants. To discover synthetic, small, allosteric inhibitors
of fXIa, we screened an in-house, unique library of 65 molecules displaying
many distinct scaffolds and varying levels of sulfation. Of these,
monosulfated benzofurans were the only group of molecules found to
inhibit fXIa (∼100% efficacy) and led to the identification
of monosulfated trimer 24 (IC50 0.82 μM)
as the most potent inhibitor. Michaelis–Menten kinetics studies
revealed a classic noncompetitive mechanism of action for 24. Although monosulfated, the inhibitors did not compete with unfractionated
heparin alluding to a novel site of interaction. Fluorescence quenching
studies indicated that trimer 24 induces major conformational
changes in the active site of fXIa. Docking studies identified a site
near Lys255 on the A3 domain of fXIa as the most probable site of
binding for 24. Factor XIa devoid of the A3 domain displayed
a major defect in the inhibition potency of 24 supporting
the docking prediction. Our work presents the sulfated benzofuran
scaffold as a promising framework to develop allosteric fXIa inhibitors
that likely function through the A3 domain.
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Affiliation(s)
- Malaika D Argade
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University , Richmond, Virginia 23219, United States
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Leung PY, Hurst S, Berny-Lang MA, Verbout NG, Gailani D, Tucker EI, Wang RK, McCarty OJT, Gruber A. Inhibition of Factor XII-Mediated Activation of Factor XI Provides Protection Against Experimental Acute Ischemic Stroke in Mice. Transl Stroke Res 2014; 3:381-9. [PMID: 23634198 DOI: 10.1007/s12975-012-0186-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Blood coagulation factor XI (FXI) is an established risk factor for acute ischemic stroke (AIS) and thrombosis, but is also needed for normal hemostasis. Contact factor XII (FXII), an upstream activator of FXI, also contributes to experimental stroke, but is not required for hemostasis. We investigated whether selectively inhibiting FXII-mediated FXI activation, while leaving other FXI and FXII functions intact, could improve the outcome of experimental AIS in mice. Twenty-four hours before induction of AIS by placement of a filament into the internal carotid artery for 60 min, mice were anticoagulated with an antibody directed against the apple 2 domain of FXI. This antibody selectively reduces the prothrombotic activation of FXI by FXIIa but does not affect activated FXI or hemostatic activation of FXI by thrombin, thus leaving hemostasis intact in mice and primates. In this model of AIS/reperfusion injury, mice that received the antibody before AIS displayed less ischemic damage, manifested as reduced cerebral infarction and fibrin deposition (thrombosis), increased cortical reperfusion, and improved neurological behavior. Further, the antibody-anticoagulated mice had no detectable hemostasis impairment. Consistent with the neuroprotective phenotype of FXII-deficient mice, our data suggest that a single molecular event, FXII-mediated FXI activation, contributes to the development of experimental AIS.
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Affiliation(s)
- Philberta Y Leung
- Department of Biomedical Engineering, Oregon Health & Science University, 3303 SW Bond Ave, Portland, OR 97239, USA; Aronora, LLC, Beaverton, OR 97006, USA
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36
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Abstract
Activation of the plasma contact system triggers several cascade systems such as the kallikrein-kinin system, the intrinsic pathway of coagulation, the classical complement cascade and the fibrinolytic system. Recent studies have shown a critical role of the contact system for arterial and venous thrombus formation and thromboembolic disease. In contrast, the function of the contact system for host-defense reactions and its physiological functions have remained enigmatic. Experimental animal studies and clinical data have linked the contact system to bacterial infections with implications for sepsis disease. The present review summarizes the role of the contact system and its activation for bacterial infections.
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Affiliation(s)
- Katrin Faye Nickel
- Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden
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Kininogen deficiency protects from ischemic neurodegeneration in mice by reducing thrombosis, blood-brain barrier damage, and inflammation. Blood 2012; 120:4082-92. [PMID: 22936662 DOI: 10.1182/blood-2012-06-440057] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Thrombosis and inflammation are hallmarks of ischemic stroke still unamenable to therapeutic interventions. High-molecular-weight kininogen (KNG) is a central constituent of the contact-kinin system which represents an interface between thrombotic and inflammatory circuits and is critically involved in stroke development. Kng(-/-) mice are protected from thrombosis after artificial vessel wall injury and lack the proinflammatory mediator bradykinin. We investigated the consequences of KNG deficiency in models of ischemic stroke. Kng(-/-) mice of either sex subjected to transient middle cerebral artery occlusion developed dramatically smaller brain infarctions and less severe neurologic deficits without an increase in infarct-associated hemorrhage. This protective effect was preserved at later stages of infarction as well as in elderly mice. Targeting KNG reduced thrombus formation in ischemic vessels and improved cerebral blood flow, and reconstitution of KNG-deficient mice with human KNG or bradykinin restored clot deposition and infarct susceptibility. Moreover, mice deficient in KNG showed less severe blood-brain barrier damage and edema formation, and the local inflammatory response was reduced compared with controls. Because KNG appears to be instrumental in pathologic thrombus formation and inflammation but dispensable for hemostasis, KNG inhibition may offer a selective and safe strategy for combating stroke and other thromboembolic diseases.
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He R, Chen D, He S. Factor XI: hemostasis, thrombosis, and antithrombosis. Thromb Res 2011; 129:541-50. [PMID: 22197449 DOI: 10.1016/j.thromres.2011.11.051] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/28/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
Abstract
Coagulation factor FXI (FXI), a plasma serine protease zymogen, has important roles in both intrinsic and extrinsic coagulation pathways and bridges the initiation and amplification phases of plasmatic hemostasis. Recent studies have provided new insight into the molecular structure and functional features of FXI and have demonstrated distinct structural and biological differences between activated factor XII (FXIIa)-mediated FXI activation and tissue factor/thrombin-mediated FXI activation. The former is important in thrombosis; the latter is more essential in hemostasis. Activated partial thromboplastin tine (aPTT) artificially reflects FXIIa-initiated intrinsic coagulation pathway in vitro. Conversely, FXIIa-inhibited diluted thromboplastin time assay may reflect tissue factor/thrombin-mediated FXI activation in vivo. Further explication of the genetic mutations of FXI deficiency has improved the understanding of the structure-function relationship of FXI. Besides its procoagulant activity, the antifibrinolytic activity of FXI was well documented in a wealth of literature. Finally, the new emerging concept of inhibiting FXI as a novel antithrombotic approach with an improved benefit-risk ratio has been supported through observations from human FXI deficiency and various animal models. Large- and small-molecule FXI inhibitors have shown promising antithrombotic effects. The present review summarizes the recent advancements in the molecular physiology of FXI and the molecular pathogenesis of FXI deficiency and discusses the evidence and progress of FXI-targeting antithrombotics development.
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Affiliation(s)
- Rong He
- Division of Hematopathology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Factor XI-deficient mice display reduced inflammation, coagulopathy, and bacterial growth during listeriosis. Infect Immun 2011; 80:91-9. [PMID: 22006565 DOI: 10.1128/iai.05568-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In mice infected sublethally with Listeria monocytogenes, fibrin is deposited at low levels within hepatic tissue, where it functions protectively by limiting bacterial growth and suppressing hemorrhagic pathology. Here we demonstrate that mice infected with lethal doses of L. monocytogenes produce higher levels of fibrin and display evidence of systemic coagulopathy (i.e., thrombocytopenia, fibrinogen depletion, and elevated levels of thrombin-antithrombin complexes). When the hepatic bacterial burden exceeds 1×10(6) CFU, levels of hepatic fibrin correlate with the bacterial burden, which also correlates with levels of hepatic mRNA encoding the hemostatic enzyme factor XI (FXI). Gene-targeted FXI-deficient mice show significantly improved survival upon challenge with high doses of L. monocytogenes and also display reduced levels of hepatic fibrin, decreased evidence of coagulopathy, and diminished cytokine production (interleukin-6 [IL-6] and IL-10). While fibrin limits the bacterial burden during sublethal listeriosis in wild-type mice, FXI-deficient mice display a significantly improved capacity to restrain the bacterial burden during lethal listeriosis despite their reduced fibrin levels. They also show less evidence of hepatic necrosis. In conjunction with suboptimal antibiotic therapy, FXI-specific monoclonal antibody 14E11 improves survival when administered therapeutically to wild-type mice challenged with high doses of L. monocytogenes. Together, these findings demonstrate the utility of murine listeriosis as a model for dissecting qualitative differences between protective and pathological host responses and reveal novel roles for FXI in exacerbating inflammation and pathogen burden during a lethal bacterial infection.
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Abstract
PURPOSE OF REVIEW Arterial and venous thrombosis are major causes of morbidity and mortality, and the incidence of thromboembolic diseases increases as a population ages. Thrombi are formed by activated platelets and fibrin. The latter is a product of the plasma coagulation system. Currently available anticoagulants such as heparins, vitamin K antagonists and inhibitors of thrombin or factor Xa target enzymes of the coagulation cascade that are critical for fibrin formation. However, fibrin is also necessary for terminating blood loss at sites of vascular injury. As a result, anticoagulants currently in clinical use increase the risk of bleeding, partially offsetting the benefits of reduced thrombosis. This review focuses on new targets for anticoagulation that are associated with minimal or no therapy-associated increased bleeding. RECENT FINDINGS Data from experimental models using mice and clinical studies of patients with hereditary deficiencies of coagulation factors XI or XII have shown that both of these clotting factors are important for thrombosis, while having minor or no apparent roles in processes that terminate blood loss (hemostasis). SUMMARY Hereditary deficiency of factor XII (Hageman factor) or factor XI, plasma proteases that initiate the intrinsic pathway of coagulation, impairs thrombus formation and provides protection from vascular occlusive events, while having a minimal impact on hemostasis. As the factor XII-factor XI pathway contributes to thrombus formation to a greater extent than to normal hemostasis, pharmacological inhibition of these coagulation factors may offer the exciting possibility of anticoagulation therapies with minimal or no bleeding risk.
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Affiliation(s)
- Felicitas Müller
- Clinical Chemistry, Department of Molecular Medicine and Surgery, University Hospital, Stockholm, Sweden
- Center of Molecular Medicine, Karolinska Institutet, University Hospital, Stockholm, Sweden
- Center of Thrombosis and Hemostasis, University Medical Center, Mainz, Germany
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Thomas Renné
- Clinical Chemistry, Department of Molecular Medicine and Surgery, University Hospital, Stockholm, Sweden
- Center of Molecular Medicine, Karolinska Institutet, University Hospital, Stockholm, Sweden
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A small-molecule factor XIa inhibitor produces antithrombotic efficacy with minimal bleeding time prolongation in rabbits. J Thromb Thrombolysis 2011; 32:129-37. [DOI: 10.1007/s11239-011-0599-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
In this issue of Blood, Zhang and colleagues demonstrate that targeting factor XI expression by antisense oligonucleotides prevents arterial and venous thrombosis in treated mice without increasing the risk of bleeding.1
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Woodruff B, Sullenger B, Becker RC. Antithrombotic Therapy in Acute Coronary Syndrome: How Far Up the Coagulation Cascade Will We Go? Curr Cardiol Rep 2010; 12:315-20. [DOI: 10.1007/s11886-010-0117-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li D, He Q, Kang T, Yin H, Jin X, Li H, Gan W, Yang C, Hu J, Wu Y, Peng L. Identification of an anticoagulant peptide that inhibits both fXIa and fVIIa/tissue factor from the blood-feeding nematode Ancylostoma caninum. Biochem Biophys Res Commun 2010; 392:155-9. [PMID: 20059979 DOI: 10.1016/j.bbrc.2009.12.177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 12/25/2009] [Indexed: 10/20/2022]
Abstract
Factor VIIa-tissue factor complex (fVIIa/TF) and factor XIa (fXIa) play important roles in the initiation and amplification of coagulation, respectively. They may be good targets for the development of novel anticoagulants to treat and prevent thromboembolic disease. In this study, we cloned, expressed and identified a novel anticoagulant peptide, AcaNAP10, from the blood-feeding nematode Ancylostoma caninum. AcaNAP10 showed potent anticoagulant activity and doubled the activated partial thromboplastin and prothrombin times at estimated concentrations of 92.9 nM and 28.8 nM, respectively. AcaNAP10 demonstrated distinct mechanisms of action compared with known anticoagulants. It inhibited fXIa and fVIIa/TF with IC(50) values of 25.76+/-1.06 nM and 123.9+/-1.71 nM, respectively. This is the first report on an anticoagulant that can inhibit both fXIa and fVIIa/TF. This anticoagulant peptide may be an alternative molecule for the development of novel anticoagulants.
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Affiliation(s)
- Deng Li
- Department of Parasitology, Guangdong Medical College, Zhanjiang 524023, China
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