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Chu HW, Chen WJ, Liu KH, Mao JY, Harroun SG, Unnikrishnan B, Lin HJ, Ma YH, Chang HT, Huang CC. Carbonization of quercetin into nanogels: a leap in anticoagulant development. J Mater Chem B 2024; 12:5391-5404. [PMID: 38716492 DOI: 10.1039/d4tb00228h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Quercetin, a flavonoid abundantly found in onions, fruits, and vegetables, is recognized for its pharmacological potential, especially for its anticoagulant properties that work by inhibiting thrombin and coagulation factor Xa. However, its clinical application is limited due to poor water solubility and bioavailability. To address these limitations, we engineered carbonized nanogels derived from quercetin (CNGsQur) using controlled pyrolysis and polymerization techniques. This led to substantial improvements in its anticoagulation efficacy, water solubility, and biocompatibility. We generated a range of CNGsQur by subjecting quercetin to varying pyrolytic temperatures and then assessed their anticoagulation capacities both in vitro and in vivo. Coagulation metrics, including thrombin clotting time (TCT), activated partial thromboplastin time (aPTT), and prothrombin time (PT), along with a rat tail bleeding assay, were utilized to gauge the efficacy. CNGsQur showed a pronounced extension of coagulation time compared to uncarbonized quercetin. Specifically, CNGsQur synthesized at 270 °C (CNGsQur270) exhibited the most significant enhancement in TCT, with a binding affinity to thrombin exceeding 400 times that of quercetin. Moreover, variants synthesized at 310 °C (CNGsQur310) and 290 °C (CNGsQur290) showed the most substantial delays in PT and aPTT, respectively. Our findings indicate that the degree of carbonization significantly influences the transformation of quercetin into various CNGsQur forms, each affecting distinct coagulation pathways. Additionally, both intravenous and oral administrations of CNGsQur were found to extend rat tail bleeding times by up to fivefold. Our studies also demonstrate that CNGsQur270 effectively delays and even prevents FeCl3-induced vascular occlusion in a dose-dependent manner in mice. Thus, controlled pyrolysis offers an innovative approach for generating quercetin-derived CNGs with enhanced anticoagulation properties and water solubility, revealing the potential for synthesizing self-functional carbonized nanomaterials from other flavonoids for diverse biomedical applications.
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Affiliation(s)
- Han-Wei Chu
- Department of Biomedical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
| | - Wan-Jyun Chen
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202301, Taiwan.
| | - Ko-Hsin Liu
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
| | - Ju-Yi Mao
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202301, Taiwan.
| | - Scott G Harroun
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Québec H3T 1J4, Canada
| | - Binesh Unnikrishnan
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202301, Taiwan.
| | - Han-Jia Lin
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202301, Taiwan.
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202301, Taiwan
| | - Yunn-Hwa Ma
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Huan-Tsung Chang
- Department of Biomedical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
- Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
- Center for Advanced Biomaterials and Technology Innovation, Chang Gung University, Taoyuan 33302, Taiwan
- Division of Breast Surgery, Department of General Surgery, Chang-Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Chih-Ching Huang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202301, Taiwan.
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202301, Taiwan
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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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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Kubitza D, Heckmann M, Distler J, Koechel A, Schwers S, Kanefendt F. Pharmacokinetics, pharmacodynamics and safety of BAY 2433334, a novel activated factor XI inhibitor, in healthy volunteers: A randomized phase 1 multiple-dose study. Br J Clin Pharmacol 2022; 88:3447-3462. [PMID: 35014061 PMCID: PMC9311154 DOI: 10.1111/bcp.15230] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022] Open
Abstract
Aim To evaluate BAY 2433334, an oral activated factor XI (FXIa) inhibitor, in volunteers. Methods Phase 1 study of healthy men at a German centre. Part A: randomized, single‐blind, multiple dose‐escalation study of BAY 2433334 (25/50/100 mg once daily [OD]) vs. placebo. Part B: similar design to Part A; evaluated BAY 2433334 25 mg twice daily. Part C: nonrandomized, open‐label study; evaluated potential interactions between BAY 2433334 (25/75 mg OD) and midazolam (7.5 mg), a CYP3A4 index substrate. Primary variables: treatment‐emergent adverse events (TEAEs; Parts A and B); area under the plasma concentration–time curve (AUC) and maximum plasma concentration of midazolam and α‐hydroxymidazolam (Part C). Study period: 18 days plus follow‐up visit. Results Parts A and B: 36 participants randomized to BAY 2433334; 12 to placebo. Part C: 48 participants assigned to BAY 2433334 plus midazolam. BAY 2433334 was well tolerated in all study parts. AUC and maximum plasma concentration of BAY 2433334 in plasma appeared dose proportional over 25–100 mg OD, with low‐to‐moderate variability in pharmacokinetic parameters. Multiple dosing caused minor‐to‐moderate accumulation and a mean terminal half‐life (15.8–17.8 h) supporting once‐daily dosing. Dose‐dependent FXIa activity inhibition and activated partial thromboplastin time prolongation were observed. BAY 2433334 appeared to have a minor effect on AUC for midazolam (ratio [90% confidence interval]: 1.1736 [1.0963–1.2564]) and α‐hydroxymidazolam (0.9864 [0.9169–1.0612]) only for BAY 2433334 75 mg OD on day 10. Conclusion Multiple dosing of BAY 2433334 in healthy volunteers was well tolerated, with a predictable pharmacokinetic/pharmacodynamic profile and no clinically relevant CYP3A4 induction or inhibition.
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Affiliation(s)
| | | | | | - Annemone Koechel
- CRS Clinical Research Services Wuppertal GmbH, Wuppertal, Germany
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Lip GY, Banerjee A, Boriani G, Chiang CE, Fargo R, Freedman B, Lane DA, Ruff CT, Turakhia M, Werring D, Patel S, Moores L. Antithrombotic Therapy for Atrial Fibrillation. Chest 2018; 154:1121-1201. [DOI: 10.1016/j.chest.2018.07.040] [Citation(s) in RCA: 481] [Impact Index Per Article: 80.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/11/2018] [Accepted: 07/24/2018] [Indexed: 02/08/2023] Open
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Mohammed BM, Cheng Q, Matafonov A, Monroe DM, Meijers JC, Gailani D. Factor XI promotes hemostasis in factor IX-deficient mice. J Thromb Haemost 2018; 16:2044-2049. [PMID: 30007049 PMCID: PMC6173617 DOI: 10.1111/jth.14243] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Indexed: 11/28/2022]
Abstract
Essentials Mice lacking factor IX (FIX) or factor XI (FXI) were tested in a saphenous vein bleeding model. FIX-deficient mice displayed a hemostatic defect and FXI-deficient mice were similar to wild type mice. Infusion of FXI or over-expression of FXI in FIX-deficient mice improved hemostasis. FXI may affect the phenotype of FIX-deficiency (hemophilia B). SUMMARY Background In humans, deficiency of coagulation factor XI may be associated with a bleeding disorder, but, until recently, FXI-deficient mice did not appear to have a hemostatic abnormality. A recent study, however, indicated that FXI-deficient mice show a moderate hemostatic defect in a saphenous vein bleeding (SVB) model. Objectives To study the effect of FXI on bleeding in mice with normal levels of the FXI substrate FIX and in mice lacking FIX (a murine model of hemophilia B). Methods Wild-type mice and mice lacking either FIX (F9- ) or FXI (F11-/- ) were tested in the SVB model. The plasma levels of FXI in F11-/- mice were manipulated by infusion of FXI or its active form FXIa, or by overexpressing FXI by the use of hydrodynamic tail vein injection. Results F9- mice showed a significant defect in the SVB model, whereas F11-/- mice and wild-type mice were indistinguishable. Intravenous infusion of FXI or FXIa into, or overexpression of FXI in, F9- mice improved hemostasis in the SVB model. Overexpression of a FXI variant lacking a FIX-binding site also improved hemostasis in F9- mice. Conclusions Although we were unable to demonstrate a hemostatic defect in F11-/- mice in the SVB model, our results support the premise that supraphysiological levels of FXI improve hemostasis in F9- mice through FIX-independent pathways.
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Affiliation(s)
- Bassem M. Mohammed
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Clinical Pharmacy, School of Pharmacy, Cairo University, Cairo, Egypt
| | - Qiufang Cheng
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Anton Matafonov
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dougald M. Monroe
- Division of Hematology/Oncology, Department of Medicine, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | - Joost C.M. Meijers
- Department of Plasma Proteins, Sanquin Research, Amsterdam, The Netherlands
- Department of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, the Netherlands
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
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Al-Horani RA, Afosah DK. Recent advances in the discovery and development of factor XI/XIa inhibitors. Med Res Rev 2018; 38:1974-2023. [PMID: 29727017 PMCID: PMC6173998 DOI: 10.1002/med.21503] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 03/09/2018] [Accepted: 04/04/2018] [Indexed: 12/12/2022]
Abstract
Factor XIa (FXIa) is a serine protease homodimer that belongs to the intrinsic coagulation pathway. FXIa primarily catalyzes factor IX activation to factor IXa, which subsequently activates factor X to factor Xa in the common coagulation pathway. Growing evidence suggests that FXIa plays an important role in thrombosis with a relatively limited contribution to hemostasis. Therefore, inhibitors targeting factor XI (FXI)/FXIa system have emerged as a paradigm-shifting strategy so as to develop a new generation of anticoagulants to effectively prevent and/or treat thromboembolic diseases without the life-threatening risk of internal bleeding. Several inhibitors of FXI/FXIa proteins have been discovered or designed over the last decade including polypeptides, active site peptidomimetic inhibitors, allosteric inhibitors, antibodies, and aptamers. Antisense oligonucleotides (ASOs), which ultimately reduce the hepatic biosynthesis of FXI, have also been introduced. A phase II study, which included patients undergoing elective primary unilateral total knee arthroplasty, revealed that a specific FXI ASO effectively protects patients against venous thrombosis with a relatively limited risk of bleeding. Initial findings have also demonstrated the potential of FXI/FXIa inhibitors in sepsis, listeriosis, and arterial hypertension. This review highlights various chemical, biochemical, and pharmacological aspects of FXI/FXIa inhibitors with the goal of advancing their development toward clinical use.
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Affiliation(s)
- Rami A. Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125
| | - Daniel K. Afosah
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219
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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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David T, Kim YC, Ely LK, Rondon I, Gao H, O'Brien P, Bolt MW, Coyle AJ, Garcia JL, Flounders EA, Mikita T, Coughlin SR. Factor XIa-specific IgG and a reversal agent to probe factor XI function in thrombosis and hemostasis. Sci Transl Med 2017; 8:353ra112. [PMID: 27559095 DOI: 10.1126/scitranslmed.aaf4331] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 07/11/2016] [Indexed: 11/02/2022]
Abstract
Thrombosis is a major cause of morbidity and mortality. Current antithrombotic drugs are not ideal in that they must balance prevention of thrombosis against bleeding risk. Inhibition of coagulation factor XI (FXI) may offer an improvement over existing antithrombotic strategies by preventing some forms of thrombosis with lower bleeding risk. To permit exploration of this hypothesis in humans, we generated and characterized a series of human immunoglobulin Gs (IgGs) that blocked FXIa active-site function but did not bind FXI zymogen or other coagulation proteases. The most potent of these IgGs, C24 and DEF, inhibited clotting in whole human blood and prevented FeCl3-induced carotid artery occlusion in FXI-deficient mice reconstituted with human FXI and in thread-induced venous thrombosis in rabbits at clinically relevant doses. At doses substantially higher than those required for inhibition of intravascular thrombus formation in these models, DEF did not increase cuticle bleeding in rabbits or cause spontaneous bleeding in macaques over a 2-week study. Anticipating the desirability of a reversal agent, we also generated a human IgG that rapidly reversed DEF activity ex vivo in human plasma and in vivo in rabbits. Thus, an active site-directed FXIa-specific antibody can block thrombosis in animal models and, together with the reversal agent, may facilitate exploration of the roles of FXIa in human disease.
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Affiliation(s)
- Tovo David
- Cardiovascular Research Institute, University of California, San Francisco, Room SC452P, 555 Mission Bay Boulevard South, San Francisco, CA 94143-3122, USA
| | - Yun Cheol Kim
- Centers for Therapeutic Innovation San Francisco, Pfizer Inc., 1700 Owens Street, San Francisco, CA 94158, USA
| | - Lauren K Ely
- Centers for Therapeutic Innovation San Francisco, Pfizer Inc., 1700 Owens Street, San Francisco, CA 94158, USA
| | - Isaac Rondon
- Centers for Therapeutic Innovation San Francisco, Pfizer Inc., 1700 Owens Street, San Francisco, CA 94158, USA
| | - Huilan Gao
- Centers for Therapeutic Innovation Boston, Pfizer Inc., 18th Floor, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Peter O'Brien
- Pharmacokinetics, Dynamics, and Metabolism Biotherapeutics and Translational Research, Pfizer Inc., 10724 Science Center Drive, San Diego, CA 92121, USA
| | - Michael W Bolt
- Drug Safety Research and Development, Pfizer Inc., 1 Burtt Road, Andover, MA 01810, USA
| | - Anthony J Coyle
- Centers for Therapeutic Innovation Boston, Pfizer Inc., 18th Floor, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Jorge L Garcia
- PMI Preclinical, 1031 Bing Street, San Carlos, CA 94070, USA
| | | | - Thomas Mikita
- Centers for Therapeutic Innovation San Francisco, Pfizer Inc., 1700 Owens Street, San Francisco, CA 94158, USA.
| | - Shaun R Coughlin
- Cardiovascular Research Institute, University of California, San Francisco, Room SC452P, 555 Mission Bay Boulevard South, San Francisco, CA 94143-3122, USA.
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Steen Burrell KA, Layzer J, Sullenger BA. A kallikrein-targeting RNA aptamer inhibits the intrinsic pathway of coagulation and reduces bradykinin release. J Thromb Haemost 2017; 15:1807-1817. [PMID: 28632925 PMCID: PMC5818257 DOI: 10.1111/jth.13760] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Indexed: 01/29/2023]
Abstract
Essentials Kallikrein amplifies contact activation and is a potential target for preventing thrombosis. We developed and characterized a kallikrein aptamer using convergent evolution and kinetic assays. Kall1-T4 prolongs intrinsic clotting time by inhibiting factor XIIa-mediated prekallikrein activation. Kall1-T4 decreases high-molecular-weight kininogen cleavage and bradykinin release. SUMMARY Background Plasma kallikrein is a serine protease that plays an integral role in many biological processes, including coagulation, inflammation, and fibrinolysis. The main function of kallikrein in coagulation is the amplification of activated factor XII (FXIIa) production, which ultimately leads to thrombin generation and fibrin clot formation. Kallikrein is generated by FXIIa-mediated cleavage of the zymogen prekallikrein, which is usually complexed with the non-enzymatic cofactor high molecular weight kininogen (HK). HK also serves as a substrate for kallikrein to generate the proinflammatory peptide bradykinin (BK). Interestingly, prekallikrein-deficient mice are protected from thrombotic events while retaining normal hemostatic capacity. Therefore, therapeutic targeting of kallikrein may provide a safer alternative to traditional anticoagulants with anti-inflammatory benefits. Objectives To isolate and characterize an RNA aptamer that binds to and inhibits plasma kallikrein, and to elucidate its mechanism of action. Methods and Results Using convergent Systematic Evolution of Ligands by Exponential Enrichment (SELEX), we isolated an RNA aptamer that targets kallikrein. This aptamer, Kall1-T4, specifically binds to both prekallikrein and kallikrein with similar subnanomolar binding affinities, and dose-dependently prolongs fibrin clot formation in an activated partial thromboplastin time (APTT) coagulation assay. In a purified in vitro system, Kall1-T4 inhibits the reciprocal activation of prekallikrein and FXII primarily by reducing the rate of FXIIa-mediated prekallikrein activation. Additionally, Kall1-T4 significantly reduces kallikrein-mediated HK cleavage and subsequent BK release. Conclusions We have isolated a specific and potent inhibitor of prekallikrein/kallikrein activity that serves as a powerful tool for further elucidating the role of kallikrein in thrombosis and inflammation.
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Affiliation(s)
- K-A Steen Burrell
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - J Layzer
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - B A Sullenger
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
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Wheeler AP, Gailani D. The Intrinsic Pathway of Coagulation as a Target for Antithrombotic Therapy. Hematol Oncol Clin North Am 2017; 30:1099-114. [PMID: 27637310 DOI: 10.1016/j.hoc.2016.05.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Plasma coagulation in the activated partial thromboplastin time assay is initiated by sequential activation of coagulation factors XII, XI, and IX. While this series of proteolytic reactions is not an accurate model for hemostasis in vivo, there is mounting evidence that factor XI and factor XII contribute to thrombosis, and that inhibiting them can produce an antithrombotic effect with a small effect on hemostasis. This article discusses the contributions of components of the intrinsic pathway to thrombosis in animal models and humans, and results of early clinical trials of drugs targeting factors IX, XI, and XII.
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Affiliation(s)
- Allison P Wheeler
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, C-3321A Medical Center North, 1161 21st Avenue, Nashville, TN 37232, USA; Department of Pediatrics, Vanderbilt University, 397 Preston Research Building, 2220 Pierce Ave, Nashville, TN 37232, USA.
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, C-3321A Medical Center North, 1161 21st Avenue, Nashville, TN 37232, USA; Hematology/Oncology Division, Department of Medicine, Vanderbilt University, 777 Preston Research Building, 2220 Pierce Avenue, Nashville, TN 37232, USA
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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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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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Abstract
INTRODUCTION Inherited fXI deficiency has been an enigma since its discovery in 1953. The variable and relatively mild symptoms in patients with even the most severe form of the disorder seem out of step with the marked abnormalities in standard clotting assays. Indeed, the contribution of factor XI to hemostasis in an individual is not adequately assessed by techniques available in modern clinical laboratories. AREAS COVERED We discuss clinical studies, genetic/genomic analyses, and advances in laboratory medicine that are reshaping our views on the role of factor XI in pathologic coagulation. We review how the disorder associated with factor XI deficiency has contributed to changes in blood coagulation models, and discuss the complex genetics of the deficiency state and its relationship to bleeding. Finally, we cover new laboratory approaches that may distinguish deficient patients who are prone to bleeding from those without such predisposition. Expert commentary: Advances in understanding the biology of factor XI have led to modifications in treatment of factor XI-deficient patients. Factor replacement is used more judiciously, and alternative approaches are gaining favor. In the future, better laboratory tests may allow us to target therapy to those patients who would benefit most.
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Affiliation(s)
- Allison P Wheeler
- a Department of Pathology, Microbiology and Immunology , Vanderbilt University , Nashville , TN , USA.,b The Department of Pediatrics , Vanderbilt University , Nashville , TN , USA
| | - David Gailani
- a Department of Pathology, Microbiology and Immunology , Vanderbilt University , Nashville , TN , USA.,c The Department of Medicine , Vanderbilt University , Nashville , TN , USA
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ten Cate-Hoek AJ, Weitz JI, Gailani D, Meijer K, Philippou H, Bouman AC, Whitney Cheung Y, van Mens TE, Govers-Riemslag JW, Vries M, Bleker S, Biedermann JS, Stoof SCM, Buller HR. Theme 3: Non-invasive management of (recurrent) venous thromboembolism (VTE) and post thrombotic syndrome (PTS). Thromb Res 2016; 136 Suppl 1:S13-8. [PMID: 26387731 DOI: 10.1016/j.thromres.2015.07.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Arina J ten Cate-Hoek
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands; Thrombosis Center, USA.
| | - Jeffrey I Weitz
- McMaster University and Thrombosis and Atherosclerosis Research Institute, Canada
| | - David Gailani
- Vanderbilt University, Department of Pathology, Microbiology and Immunology, Nashville, USA
| | - Karina Meijer
- University of Groningen, University Medical Center Groningen, Department of Hematology, Netherlands
| | - Helen Philippou
- University of Leeds, Division of Cardiovascular and Diabetes Research, The LIGHT Labs, Leeds, UK
| | - Annemieke C Bouman
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands; Thrombosis Center, USA
| | - Y Whitney Cheung
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Thijs E van Mens
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Jose W Govers-Riemslag
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands
| | - Minka Vries
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands
| | - Suzanne Bleker
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Jossi S Biedermann
- Erasmus University Medical Center, Rotterdam, Department of Hematology, Netherlands
| | - S Carina M Stoof
- Erasmus University Medical Center, Rotterdam, Department of Hematology, Netherlands
| | - Harry R Buller
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
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15
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Gailani D, Gruber A. Factor XI as a Therapeutic Target. Arterioscler Thromb Vasc Biol 2016; 36:1316-22. [PMID: 27174099 DOI: 10.1161/atvbaha.116.306925] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 04/29/2016] [Indexed: 11/16/2022]
Abstract
Factor XIa is a plasma serine protease that contributes to thrombin generation primarily through proteolytic activation of factor IX. Traditionally considered part of the intrinsic pathway of coagulation, several lines of evidence now suggest that factor XIa serves as an interface between the vitamin-K-dependent thrombin generation mechanism and the proinflammatory kallikrein-kinin system, allowing the 2 systems to influence each other. Work with animal models and results from epidemiological surveys of human populations support a role for factor XIa in thromboembolic disease. These data and the clinical observation that deficiency of factor XI, the zymogen of factor XIa, produces a relatively mild bleeding disorder suggest that drugs targeting factor XI or XIa could produce an antithrombotic effect while leaving hemostasis largely intact. Results of a recent trial comparing antisense-induced factor XI reduction to standard-dose low molecular-weight heparin as prophylaxis for venous thrombosis during knee replacement are encouraging in this regard. Here, we discuss recent findings on the biochemistry, physiology, and pathology of factor XI as they relate to thromboembolic disease.
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Affiliation(s)
- David Gailani
- From the Department of Pathology, Microbiology and Immunology and Department of Medicine, Vanderbilt University, Nashville, TN (D.G.); and Aronora, Inc, Portland, OR (A.G.).
| | - Andras Gruber
- From the Department of Pathology, Microbiology and Immunology and Department of Medicine, Vanderbilt University, Nashville, TN (D.G.); and Aronora, Inc, Portland, OR (A.G.)
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16
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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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17
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The impact of thrombin generation and rotation thromboelastometry on assessment of severity of factor XI deficiency. Thromb Res 2015; 136:465-73. [DOI: 10.1016/j.thromres.2015.06.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/28/2015] [Accepted: 06/17/2015] [Indexed: 11/22/2022]
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18
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FXIa and platelet polyphosphate as therapeutic targets during human blood clotting on collagen/tissue factor surfaces under flow. Blood 2015; 126:1494-502. [PMID: 26136249 DOI: 10.1182/blood-2015-04-641472] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/18/2015] [Indexed: 11/20/2022] Open
Abstract
Factor XIIa (FXIIa) and factor XIa (FXIa) contribute to thrombosis in animal models, whereas platelet-derived polyphosphate (polyP) may potentiate contact or thrombin-feedback pathways. The significance of these mediators in human blood under thrombotic flow conditions on tissue factor (TF) -bearing surfaces remains inadequately resolved. Human blood (corn trypsin inhibitor treated [4 μg/mL]) was tested by microfluidic assay for clotting on collagen/TF at TF surface concentration ([TF]wall) from ∼0.1 to 2 molecules per μm(2). Anti-FXI antibodies (14E11 and O1A6) or polyP-binding protein (PPXbd) were used to block FXIIa-dependent FXI activation, FXIa-dependent factor IX (FIX) activation, or platelet-derived polyP, respectively. Fibrin formation was sensitive to 14E11 at 0 to 0.1 molecules per µm(2) and sensitive to O1A6 at 0 to 0.2 molecules per µm(2). However, neither antibody reduced fibrin generation at ∼2 molecules per µm(2) when the extrinsic pathway became dominant. Interestingly, PPXbd reduced fibrin generation at low [TF]wall (0.1 molecules per µm(2)) but not at zero or high [TF]wall, suggesting a role for polyP distinct from FXIIa activation and requiring low extrinsic pathway participation. Regardless of [TF]wall, PPXbd enhanced fibrin sensitivity to tissue plasminogen activator and promoted clot retraction during fibrinolysis concomitant with an observed PPXbd-mediated reduction of fibrin fiber diameter. This is the first detection of endogenous polyP function in human blood under thrombotic flow conditions. When triggered by low [TF]wall, thrombosis may be druggable by contact pathway inhibition, although thrombolytic susceptibility may benefit from polyP antagonism regardless of [TF]wall.
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19
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Zantek ND, Hsu P, Meijer P, Smock KJ, Plumhoff EA, Refaai MA, Van Cott EM. Quality of factor XI activity testing in North American Specialized Coagulation Laboratories. Int J Lab Hematol 2015; 37 Suppl 1:99-107. [DOI: 10.1111/ijlh.12359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/16/2015] [Indexed: 11/30/2022]
Affiliation(s)
- N. D. Zantek
- Department of Laboratory Medicine and Pathology; University of Minnesota; Minneapolis MN USA
| | - P. Hsu
- Department of Pathology/Laboratory Medicine; Hofstra North Shore-Long Island Jewish School of Medicine; Lake Success NY USA
| | - P. Meijer
- ECAT Foundation; Voorschoten The Netherlands
| | - K. J. Smock
- Department of Pathology; ARUP Laboratories; University of Utah; Salt Lake City UT USA
| | - E. A. Plumhoff
- Department of Laboratory Medicine and Pathology; Mayo Clinic; Rochester MN USA
| | - M. A. Refaai
- Department of Pathology and Laboratory Medicine; University of Rochester School of Medicine and Dentistry; Rochester NY USA
| | - E. M. Van Cott
- Department of Pathology; Massachusetts General Hospital; Boston MA USA
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