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Malik RA, Zhou J, Fredenburgh JC, Crosby J, Revenko AS, Healey JS, Weitz JI. Histidine-Rich Glycoprotein Modulates the Toxic Effects of High-Dose Polyphosphate in Mice. Arterioscler Thromb Vasc Biol 2024; 44:1658-1670. [PMID: 38752349 DOI: 10.1161/atvbaha.124.320899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/02/2024] [Indexed: 06/28/2024]
Abstract
BACKGROUND Polyphosphate (polyP), a procoagulant released from platelets, activates coagulation via the contact system and modulates cardiomyocyte viability. High-dose intravenous polyP is lethal in mice, presumably because of thrombosis. Previously, we showed that HRG (histidine-rich glycoprotein) binds polyP and attenuates its procoagulant effects. In this study, we investigated the mechanisms responsible for the lethality of intravenous polyP in mice and the impact of HRG on this process. METHODS The survival of wild-type or HRG-deficient mice given intravenous synthetic or platelet-derived polyP in doses up to 50 mg/kg or saline was compared. To determine the contribution of thrombosis, the effect of FXII (factor XII) knockdown or enoxaparin on polyP-induced fibrin deposition in the lungs was examined. To assess cardiotoxicity, the ECG was continuously monitored, the levels of troponin I and the myocardial band of creatine kinase were quantified, and the viability of a cultured murine cardiomyocyte cell line exposed to polyP in the absence or presence of HRG was determined. RESULTS In HRG-deficient mice, polyP was lethal at 30 mg/kg, whereas it was lethal in wild-type mice at 50 mg/kg. Although FXII knockdown or enoxaparin administration attenuated polyP-induced fibrin deposition in the lungs, neither affected mortality. PolyP induced dose-dependent ECG abnormalities, including heart block and ST-segment changes, and increased the levels of troponin and myocardial band of creatine kinase, effects that were more pronounced in HRG-deficient mice than in wild-type mice and were attenuated when HRG-deficient mice were given supplemental HRG. Consistent with its cardiotoxicity, polyP reduced the viability of cultured cardiomyocytes in a dose-dependent manner, an effect attenuated with supplemental HRG. CONCLUSIONS High-dose intravenous polyP is cardiotoxic in mice, and HRG modulates this effect.
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Affiliation(s)
- Rida A Malik
- Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada (R.A.M., J.Z., J.C.F., J.I.W.)
- Department of Medical Sciences (R.A.M.), McMaster University, Hamilton, Ontario, Canada
| | - Ji Zhou
- Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada (R.A.M., J.Z., J.C.F., J.I.W.)
- Department of Medicine (J.Z., J.C.F., J.S.H., J.I.W.), McMaster University, Hamilton, Ontario, Canada
| | - James C Fredenburgh
- Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada (R.A.M., J.Z., J.C.F., J.I.W.)
- Department of Medicine (J.Z., J.C.F., J.S.H., J.I.W.), McMaster University, Hamilton, Ontario, Canada
| | - Jeff Crosby
- Department of Pulmonary and Oncology Drug Discovery, Ionis Pharmaceuticals, Inc, Carlsbad, CA (J.C., A.S.R.)
| | - Alexey S Revenko
- Department of Pulmonary and Oncology Drug Discovery, Ionis Pharmaceuticals, Inc, Carlsbad, CA (J.C., A.S.R.)
| | - Jeff S Healey
- Department of Medicine (J.Z., J.C.F., J.S.H., J.I.W.), McMaster University, Hamilton, Ontario, Canada
- Population Health Research Institute, Hamilton, Ontario, Canada (J.S.H.)
| | - Jeffrey I Weitz
- Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada (R.A.M., J.Z., J.C.F., J.I.W.)
- Department of Medicine (J.Z., J.C.F., J.S.H., J.I.W.), McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences (J.I.W.), McMaster University, Hamilton, Ontario, Canada
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Taskin B, Kohs TC, Shatzel JJ, Puy C, McCarty OJ. Factor XI as a therapeutic target in neuroinflammatory disease. Curr Opin Hematol 2024; 31:32-38. [PMID: 37694771 PMCID: PMC10843631 DOI: 10.1097/moh.0000000000000787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
PURPOSE OF REVIEW This review summarizes the pathophysiology and potential therapeutic options for treatment of multiple sclerosis, a common neuronal demyelinating disorder affecting 2.2 million people worldwide. As an autoimmune disorder, multiple sclerosis is associated with neuroinflammation and increased permeability of the blood-brain barrier (BBB), although the cause linking multiple sclerosis with compromised barrier function remains ill-defined. It has been previously shown that coagulation factors, including thrombin and fibrin, exacerbate the inflammatory processes and permeability of the BBB. RECENT FINDINGS Increased levels of the coagulation factor (F) XII have been found in patients presenting with relapsing-remitting multiple sclerosis, with a deleterious role for FXII being validated in murine model of multiple sclerosis, experimental autoimmune encephalitis (EAE). Recent work has uncovered a role for the major substrate activated by FXII and thrombin, FXI, in the disorder of EAE. The study found that pharmacological targeting of FXI decreased clinical symptoms, lymphocyte invasion, and white matter destruction in a multiple sclerosis model. SUMMARY This review emphasizes the role of FXII and FXI in regulating barrier function and the immune response in neuroinflammation. These new findings broaden the potential for therapeutic utility of FXI inhibitors beyond thrombosis to include neuroinflammatory diseases associated with compromised BBB function, including multiple sclerosis.
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Affiliation(s)
- Berk Taskin
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, US
| | - Tia C.L. Kohs
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, US
| | - Joseph J. Shatzel
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, US
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR
| | - Cristina Puy
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, US
| | - Owen J.T. McCarty
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, US
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR
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Pfeffer MA, Kohs TC, Vu HH, Jordan KR, Wang JSH, Lorentz CU, Tucker EI, Puy C, Olson SR, DeLoughery TG, Hinds MT, Keshari RS, Gailani D, Lupu F, McCarty OJ, Shatzel JJ. Factor XI Inhibition for the Prevention of Catheter-Associated Thrombosis in Patients With Cancer Undergoing Central Line Placement: A Phase 2 Clinical Trial. Arterioscler Thromb Vasc Biol 2024; 44:290-299. [PMID: 37970718 PMCID: PMC10877270 DOI: 10.1161/atvbaha.123.319692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 10/24/2023] [Indexed: 11/17/2023]
Abstract
BACKGROUND Despite the ubiquitous utilization of central venous catheters in clinical practice, their use commonly provokes thromboembolism. No prophylactic strategy has shown sufficient efficacy to justify routine use. Coagulation factors FXI (factor XI) and FXII (factor XII) represent novel targets for device-associated thrombosis, which may mitigate bleeding risk. Our objective was to evaluate the safety and efficacy of an anti-FXI mAb (monoclonal antibody), gruticibart (AB023), in a prospective, single-arm study of patients with cancer receiving central line placement. METHODS We enrolled ambulatory cancer patients undergoing central line placement to receive a single dose of gruticibart (2 mg/kg) administered through the venous catheter within 24 hours of placement and a follow-up surveillance ultrasound at day 14 for evaluation of catheter thrombosis. A parallel, noninterventional study was used as a comparator. RESULTS In total, 22 subjects (n=11 per study) were enrolled. The overall incidence of catheter-associated thrombosis was 12.5% in the interventional study and 40.0% in the control study. The anti-FXI mAb, gruticibart, significantly prolonged the activated partial thromboplastin time in all subjects on day 14 compared with baseline (P<0.001). Gruticibart was well tolerated and without infusion reactions, drug-related adverse events, or clinically relevant bleeding. Platelet flow cytometry demonstrated no difference in platelet activation following administration of gruticibart. T (thrombin)-AT (antithrombin) and activated FXI-AT complexes increased following central line placement in the control study, which was not demonstrated in our intervention study. CRP (C-reactive protein) did not significantly increase on day 14 in those who received gruticibart, but it did significantly increase in the noninterventional study. CONCLUSIONS FXI inhibition with gruticibart was well tolerated without any significant adverse or bleeding-related events and resulted in a lower incidence of catheter-associated thrombosis on surveillance ultrasound compared with the published literature and our internal control study. These findings suggest that targeting FXI could represent a safe intervention to prevent catheter thrombosis. REGISTRATION URL: https://www.clinicaltrials.gov; Unique identifier: NCT04465760.
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Affiliation(s)
- Michael A. Pfeffer
- Division of Hematology and Medical Oncology, Oregon Health
& Science University, Portland, OR
| | - Tia C.L. Kohs
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Helen H. Vu
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Kelley R. Jordan
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Jenny Si Han Wang
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Christina U. Lorentz
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
- Aronora, Inc., Portland, OR
| | - Erik I. Tucker
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
- Aronora, Inc., Portland, OR
| | - Cristina Puy
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Sven R. Olson
- Division of Hematology and Medical Oncology, Oregon Health
& Science University, Portland, OR
| | - Thomas G. DeLoughery
- Division of Hematology and Medical Oncology, Oregon Health
& Science University, Portland, OR
| | - Monica T. Hinds
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Ravi S. Keshari
- Cardiovascular Biology Research Program, Oklahoma Medical
Research Foundation, Oklahoma City, OK
| | - David Gailani
- Department of Pathology, Microbiology and Immunology,
Vanderbilt University Medical Center, Nashville, TN
| | - Florea Lupu
- Cardiovascular Biology Research Program, Oklahoma Medical
Research Foundation, Oklahoma City, OK
| | - Owen J.T. McCarty
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
| | - Joseph J. Shatzel
- Division of Hematology and Medical Oncology, Oregon Health
& Science University, Portland, OR
- Department of Biomedical Engineering, Oregon Health &
Science University, Portland, OR
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Belcher HA, Guthold M, Hudson NE. What is the diameter of a fibrin fiber? Res Pract Thromb Haemost 2023; 7:100285. [PMID: 37601015 PMCID: PMC10439396 DOI: 10.1016/j.rpth.2023.100285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/31/2023] [Accepted: 06/05/2023] [Indexed: 08/22/2023] Open
Abstract
Background Altered fibrin fiber structure is linked to pathologic states, including coronary heart disease, ischemic stroke, and atherosclerosis. However, several different techniques are commonly utilized for studying fibrin structures, and comparison of results obtained using different techniques can be challenging due to lack of standardization. Objectives This study provides a path toward standardization by comparing fibrin fiber diameters for a range of physiologic fibrinogen and thrombin concentrations using multiple different complementary experimental methods. Methods We determined fiber diameter using scanning electron microscopy (SEM), superresolution (stochastic optical reconstruction microscopy) fluorescence microscopy, and 4 commonly utilized turbidimetric approaches to determine the congruence between the results and the conditions under which each should be used. Results We found that diameter values obtained using SEM and superresolution imaging agree within 10% for nearly all conditions tested. We also found that when a wavelength range of 500 to 800 nm was used for measurements and accounting for the wavelength dependence of the refractive index and specific refractive index increment, diameters obtained using the corrected Yeromonahos turbidimetric approach agree with SEM within 20% for most conditions. Conclusion We performed a systematic, multitechnique survey assessing fibrin fiber diameters under a range of biochemical conditions. The similarity in the diameter values obtained using SEM and superresolution imaging suggests that drying and fixation during SEM sample preparation do not dramatically alter fiber cross-sections. Congruence, under certain conditions, between diameter values obtained using SEM, superresolution fluorescence imaging, and turbidimetry demonstrates the feasibility of a fibrin diameter standardization project.
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Affiliation(s)
- Heather A. Belcher
- Department of Physics, East Carolina University, Greenville, NC 27858, USA
| | - Martin Guthold
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Nathan E. Hudson
- Department of Physics, East Carolina University, Greenville, NC 27858, USA
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5
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Belcher HA, Litwa K, Guthold M, Hudson NE. The Applicability of Current Turbidimetric Approaches for Analyzing Fibrin Fibers and Other Filamentous Networks. Biomolecules 2022; 12:biom12060807. [PMID: 35740932 PMCID: PMC9221518 DOI: 10.3390/biom12060807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/02/2022] [Accepted: 06/05/2022] [Indexed: 12/07/2022] Open
Abstract
Turbidimetry is an experimental technique often used to study the structure of filamentous networks. To extract structural properties such as filament diameter from turbidimetric data, simplifications to light scattering theory must be employed. In this work, we evaluate the applicability of three commonly utilized turbidimetric analysis approaches, each using slightly different simplifications. We make a specific application towards analyzing fibrin fibers, which form the structural scaffold of blood clots, but the results are generalizable. Numerical simulations were utilized to assess the applicability of each approach across a range of fiber lengths and diameters. Simulation results indicated that all three turbidimetric approaches commonly underestimate fiber diameter, and that the “Carr-Hermans” approach, utilizing wavelengths in the range of 500−800 nm, provided <10% error for the largest number of diameter/length combinations. These theoretical results were confirmed, under select conditions, via the comparison of fiber diameters extracted from experimental turbidimetric data, with diameters obtained using super-resolution microscopy.
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Affiliation(s)
- Heather A. Belcher
- Department of Physics, East Carolina University, Greenville, NC 27858, USA;
| | - Karen Litwa
- Department of Anatomy & Cell Biology, East Carolina University, Greenville, NC 27858, USA;
| | - Martin Guthold
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA;
| | - Nathan E. Hudson
- Department of Physics, East Carolina University, Greenville, NC 27858, USA;
- Correspondence: ; Tel.: +1-252-737-5349
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6
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Ruhoff AM, Hong JK, Gao L, Singh J, Tran C, Mackie G, Waterhouse A. Biomaterial Wettability Affects Fibrin Clot Structure and Fibrinolysis. Adv Healthc Mater 2021; 10:e2100988. [PMID: 34423587 DOI: 10.1002/adhm.202100988] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/29/2021] [Indexed: 12/20/2022]
Abstract
Thrombosis on blood-contacting medical devices can cause patient fatalities through device failure and unstable thrombi causing embolism. The effect of material wettability on fibrin network formation, structure, and stability is poorly understood. Under static conditions, fibrin fiber network volume and density increase in clots formed on hydrophilic compared to hydrophobic polystyrene surfaces. This correlates with reduced plasma clotting time and increased factor XIIa (FXIIa) activity. These structural differences are consistent up to 50 µm away from the material surface and are FXIIa dependent. Fibrin forms fibers immediately at the material interface on hydrophilic surfaces but are incompletely formed in the first 5 µm above hydrophobic surfaces. Additionally, fibrin clots on hydrophobic surfaces have increased susceptibility to fibrinolysis compared to clots formed on hydrophilic surfaces. Under low-flow conditions, clots are still denser on hydrophilic surfaces, but only 5 µm above the surface, showing the combined effect of the surface wettability and coagulation factor dilution with low flow. Overall, wettability affects fibrin fiber formation at material interfaces, which leads to differences in bulk fibrin clot density and susceptibility to fibrinolysis. These findings have implications for thrombus formed in stagnant or low-flow regions of medical devices and the design of nonthrombogenic materials.
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Affiliation(s)
- Alexander M. Ruhoff
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
| | - Jun Ki Hong
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- School of Chemistry Faculty of Science The University of Sydney Sydney NSW 2006 Australia
- School of Medical Sciences Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
- The University of Sydney Nano Institute The University of Sydney Sydney NSW 2006 Australia
| | - Lingzi Gao
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
| | - Jasneil Singh
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- School of Medical Sciences Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
- School of Biomedical Engineering Faculty of Engineering The University of Sydney Sydney NSW 2006 Australia
| | - Clara Tran
- School of Biomedical Engineering Faculty of Engineering The University of Sydney Sydney NSW 2006 Australia
- School of Physics Faculty of Science The University of Sydney Sydney NSW 2006 Australia
| | - Grace Mackie
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
| | - Anna Waterhouse
- Heart Research Institute 7 Eliza Street Newtown NSW 2042 Australia
- The Charles Perkins Centre The University of Sydney Sydney NSW 2006 Australia
- School of Medical Sciences Faculty of Medicine and Health The University of Sydney Sydney NSW 2006 Australia
- The University of Sydney Nano Institute The University of Sydney Sydney NSW 2006 Australia
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The pleiotropic effects of antithrombotic drugs in the metabolic-cardiovascular-neurodegenerative disease continuum: impact beyond reduced clotting. Clin Sci (Lond) 2021; 135:1015-1051. [PMID: 33881143 DOI: 10.1042/cs20201445] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/07/2021] [Accepted: 04/13/2021] [Indexed: 12/25/2022]
Abstract
Antithrombotic drugs are widely used for primary and secondary prevention, as well as treatment of many cardiovascular disorders. Over the past few decades, major advances in the pharmacology of these agents have been made with the introduction of new drug classes as novel therapeutic options. Accumulating evidence indicates that the beneficial outcomes of some of these antithrombotic agents are not solely related to their ability to reduce thrombosis. Here, we review the evidence supporting established and potential pleiotropic effects of four novel classes of antithrombotic drugs, adenosine diphosphate (ADP) P2Y12-receptor antagonists, Glycoprotein IIb/IIIa receptor Inhibitors, and Direct Oral Anticoagulants (DOACs), which include Direct Factor Xa (FXa) and Direct Thrombin Inhibitors. Specifically, we discuss the molecular evidence supporting such pleiotropic effects in the context of cardiovascular disease (CVD) including endothelial dysfunction (ED), atherosclerosis, cardiac injury, stroke, and arrhythmia. Importantly, we highlight the role of DOACs in mitigating metabolic dysfunction-associated cardiovascular derangements. We also postulate that DOACs modulate perivascular adipose tissue inflammation and thus, may reverse cardiovascular dysfunction early in the course of the metabolic syndrome. In this regard, we argue that some antithrombotic agents can reverse the neurovascular damage in Alzheimer's and Parkinson's brain and following traumatic brain injury (TBI). Overall, we attempt to provide an up-to-date comprehensive review of the less-recognized, beneficial molecular aspects of antithrombotic therapy beyond reduced thrombus formation. We also make a solid argument for the need of further mechanistic analysis of the pleiotropic effects of antithrombotic drugs in the future.
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8
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Sniecinski RM, Levy JH. The Contact Activation System: Problems and Paradoxes for Cardiac Anesthesiologists. Anesth Analg 2020; 131:152-154. [PMID: 32541589 DOI: 10.1213/ane.0000000000004745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Roman M Sniecinski
- From the Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia
| | - Jerrold H Levy
- Department of Anesthesiology and Critical Care, Duke University School of Medicine, Durham, North Carolina
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Abstract
The vasculature is a dynamic environment in which blood platelets constantly survey the endothelium for sites of vessel damage. The formation of a mechanically coherent hemostatic plug to prevent blood loss relies on a coordinated series of ligand-receptor interactions governing the recruitment, activation, and aggregation of platelets. The physical biology of each step is distinct in that the recruitment of platelets depends on the mechanosensing of the platelet receptor glycoprotein Ib for the adhesive protein von Willebrand factor, whereas platelet activation and aggregation are responsive to the mechanical forces sensed at adhesive junctions between platelets and at the platelet-matrix interface. Herein we take a biophysical perspective to discuss the current understanding of platelet mechanotransduction as well as the measurement techniques used to quantify the physical biology of platelets in the context of thrombus formation under flow.
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Affiliation(s)
- Caroline E Hansen
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Yongzhi Qiu
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Owen J T McCarty
- Department of Cell, Developmental, and Cancer Biology, Oregon Health & Science University, Portland, Oregon 97239, USA.,Division of Hematology and Medical Oncology and Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Wilbur A Lam
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
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The contact system at the crossroads of various key patho- physiological functions: Update on present understanding, laboratory exploration and future perspectives. Transfus Apher Sci 2019; 58:216-222. [PMID: 30954379 DOI: 10.1016/j.transci.2019.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The contact system initiates the intrinsic pathway of coagulation and is started by Factor XII activation, which then activates prekallicrein to kallicrein and Factor XI to Factor XIa and, in the presence of high molecular weight kininogen, forms a "contact phase activation loop", that amplifies Factor XII activation. FXII deficiency is not associated with bleeding tendencies, but when the blood clots, the thrombus is less dense, thus favoring antithrombotic protection. Activated Factor XII inhibition emerges as an efficient target for preventing thrombo-embolic diseases without inducing a hemorrhagic risk. Activated Factor XII exhibits other activities, in that it can activate complement and provoke inflammation, contributing to innate immunity. It also stimulates fibrinolysis through uPA activation from scu-PA. Among the other components of the contact phase, Factor XI has a more important role in coagulation pathways and can directly activate FX, FVIII and FV, in a FIX independent pathway. Its deficiency is associated with a mild bleeding diathesis ("pseudo-hemophilia" or hemophilia C), with a variable incidence among kindreds. Recently, the occurrence of thrombotic events the same day following infusion of immunoglobulin concentrates has been demonstrated to be caused by the presence of trace amounts of activated Factor XI, pointing out the key role of this factor for thrombogenicity. Prekallicrein can be activated at the endothelial surface in the presence of high molecular weight kininogen, whose cleavage generates bradykinins and contributes to vessel tonicity and inflammation. The contact phase, through its activation loop, is then an important physiological system, which can initiate and regulate various biological functions and is at the crossroads of various biological activities. Many of the body's physiological functions are intimately linked between them, making the global approach of special usefulness for understanding the interactions which can result from any abnormality of one of them. New pharmaceutical drugs targeting a defined activity need to be investigated for all the possible interferences or side effects. In this article we aim to present and summarize the present understanding of contact phase system activation and regulation, its involvement in various physiological functions, and the laboratory tools for its exploration.
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