101
|
Hyaluronic acid decreases the mechanical stability, but increases the lytic resistance of fibrin matrices. Matrix Biol 2017; 63:55-68. [DOI: 10.1016/j.matbio.2016.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 11/22/2022]
|
102
|
Blotnick E, Sol A, Muhlrad A. Histones bundle F-actin filaments and affect actin structure. PLoS One 2017; 12:e0183760. [PMID: 28846729 PMCID: PMC5573295 DOI: 10.1371/journal.pone.0183760] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 08/10/2017] [Indexed: 12/16/2022] Open
Abstract
Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300–400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.
Collapse
Affiliation(s)
- Edna Blotnick
- Department of Medical Neurobiology, Institute for Medical Research-Israel–Canada, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Asaf Sol
- Institute of Dental Sciences, Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Andras Muhlrad
- Institute of Dental Sciences, Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
103
|
Jeffery U, Ruterbories L, Hanel R, LeVine DN. Cell-Free DNA and DNase Activity in Dogs with Immune-Mediated Hemolytic Anemia. J Vet Intern Med 2017; 31:1441-1450. [PMID: 28833583 PMCID: PMC5598899 DOI: 10.1111/jvim.14808] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/04/2017] [Accepted: 07/19/2017] [Indexed: 12/21/2022] Open
Abstract
Background Immune‐mediated hemolytic anemia (IMHA) in dogs has a high risk of thrombosis and is associated with marked neutrophilia and necrosis. Cell death and release of neutrophil extracellular traps contribute to increased serum concentrations of cell‐free DNA, and in human autoimmune disease reduced DNase activity further increases cell‐free DNA. Free DNA in blood has prothrombotic properties and could contribute to hypercoagulability in IMHA. Hypothesis Cell‐free DNA is elevated and DNase activity reduced in dogs with IMHA compared to healthy dogs. Animals Dogs presenting to two referral hospitals with IMHA (n = 28) and healthy controls (n = 20). Methods Prospective observational study. Blood was collected and death and thrombotic events occurring in the first 14 days after hospitalization recorded. DNA was extracted from plasma with a commercial kit and quantified by PicoGreen fluorescence. DNase activity of serum was measured by radial diffusion assay. Results Cell‐free DNA was significantly higher in cases (median: 45 ng/mL, range: 10–2334 ng/mL) than controls (26 ng/mL, range 1–151 ng/mL, P = 0.0084). DNase activity was not different between cases and controls (P = 0.36). Four cases died and there were five suspected or confirmed thrombotic events. Cell‐free DNA concentration was associated with death (odds ratio for upper quartile versus lower 3 quartiles: 15; 95% confidence interval 1.62–201; P = 0.03) but not thrombosis (P = 0.57). Conclusions and Clinical Importance Cell‐free DNA is elevated in dogs with IMHA and likely reflects increased release rather than impaired degradation of DNA. Cell‐free DNA concentration is potentially associated with death and might be a prognostic indicator, but this requires confirmation in a larger population.
Collapse
Affiliation(s)
- U Jeffery
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA
| | - L Ruterbories
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - R Hanel
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - D N LeVine
- Department of Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA
| |
Collapse
|
104
|
Qi H, Yang S, Zhang L. Neutrophil Extracellular Traps and Endothelial Dysfunction in Atherosclerosis and Thrombosis. Front Immunol 2017; 8:928. [PMID: 28824648 PMCID: PMC5545592 DOI: 10.3389/fimmu.2017.00928] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/20/2017] [Indexed: 12/23/2022] Open
Abstract
Cardiovascular diseases are a leading cause of mortality and morbidity worldwide. Neutrophils are a component of the innate immune system which protect against pathogen invasion; however, the contribution of neutrophils to cardiovascular disease has been underestimated, despite infiltration of leukocyte subsets being a known driving force of atherosclerosis and thrombosis. In addition to their function as phagocytes, neutrophils can release their extracellular chromatin, nuclear protein, and serine proteases to form net-like fiber structures, termed neutrophil extracellular traps (NETs). NETs can entrap pathogens, induce endothelial activation, and trigger coagulation, and have been detected in atherosclerotic and thrombotic lesions in both humans and mice. Moreover, NETs can induce endothelial dysfunction and trigger proinflammatory immune responses. Overall, current data indicate that NETs are not only present in plaques and thrombi but also have causative roles in triggering formation of atherosclerotic plaques and venous thrombi. This review is focused on published findings regarding NET-associated endothelial dysfunction during atherosclerosis, atherothrombosis, and venous thrombosis pathogenesis. The NET structure is a novel discovery that will find its appropriate place in our new understanding of cardiovascular disease. In addition, NETs have high potential to be further explored toward much better treatment of atherosclerosis and venous thromboembolism in clinic.
Collapse
Affiliation(s)
- Haozhe Qi
- Department of Vascular Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuofei Yang
- Department of Vascular Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lan Zhang
- Department of Vascular Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
105
|
Gordon CE, Chitalia VC, Sloan JM, Salant DJ, Coleman DL, Quillen K, Ravid K, Francis JM. Thrombotic Microangiopathy: A Multidisciplinary Team Approach. Am J Kidney Dis 2017; 70:715-721. [PMID: 28720207 DOI: 10.1053/j.ajkd.2017.05.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/14/2017] [Indexed: 12/20/2022]
Abstract
Thrombotic microangiopathy (TMA) is characterized by the presence of microangiopathic hemolytic anemia and thrombocytopenia along with organ dysfunction, and pathologically, by the presence of microthrombi in multiple microvascular beds. Delays in diagnosis and initiation of therapy are common due to the low incidence, variable presentation, and poor awareness of these diseases, underscoring the need for interdisciplinary approaches to clinical care for TMA. We describe a new approach to improve clinical management via a TMA team that originally stemmed from an Affinity Research Collaborative team focused on thrombosis and hemostasis. The TMA team consists of clinical faculty from different disciplines who together are charged with the responsibility to quickly analyze clinical presentations, guide laboratory testing, and streamline prompt institution of treatment. The TMA team also includes faculty members from a broad range of disciplines collaborating to elucidate the pathogenesis of TMA. To this end, a clinical database and biorepository have been constructed. TMA leaders educate front-line providers from other departments through presentations in various forums across multiple specialties. Facilitated by an Affinity Research Collaborative mechanism, we describe an interdisciplinary team dedicated to improving both clinical care and translational research in TMA.
Collapse
Affiliation(s)
- Craig E Gordon
- Renal Section, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - Vipul C Chitalia
- Renal Section, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - J Mark Sloan
- Hematology-Oncology Section, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - David J Salant
- Renal Section, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - David L Coleman
- Department of Medicine, Boston University School of Medicine, Boston, MA
| | - Karen Quillen
- Hematology-Oncology Section, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - Katya Ravid
- Department of Medicine, Boston University School of Medicine, Boston, MA; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Jean M Francis
- Renal Section, Department of Medicine, Boston University School of Medicine, Boston, MA.
| |
Collapse
|
106
|
Preissner KT, Herwald H. Extracellular nucleic acids in immunity and cardiovascular responses: between alert and disease. Thromb Haemost 2017; 117:1272-1282. [PMID: 28594050 DOI: 10.1160/th-16-11-0858] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/07/2017] [Indexed: 12/18/2022]
Abstract
Severe inflammatory complications are a potential consequence in patients with predetermined conditions of infections, pulmonary diseases, or cardiovascular disorders. Notably, the amplitude of the inflammatory response towards these complications can dictate the disease progression and outcome. During the recent years, evidence from basic research as well as from clinical studies has identified self-extracellular nucleic acids as important players in the crosstalk between immunity and cardiovascular diseases. These stress- or injury-induced endogenous polymeric macromolecules not only serve as "alarmins" or "Danger-associated molecular patterns" (DAMPs), but their functional repertoire goes far beyond such activities in innate immunity. In fact, (patho-) physiological functions of self-extracellular DNA and RNA are associated and in many cases causally related to arterial and venous thrombosis, atherosclerosis, ischemia-reperfusion injury or tumour progression. Yet, the underlying molecular mechanisms are far from being completely understood. Interestingly enough, however, novel antagonistic approaches in vitro and in vivo, particularly using natural endonucleases or synthetic nucleic acid binding polymers, appear to be promising and safe therapeutic options for future studies. The aim of this review article is to provide an overview of the current state of (patho-) physiological functions of self-extracellular nucleic acids with special emphasis on their role as beneficial / alerting or adverse / damaging factors in connection with immune responses, inflammation, thrombosis, and cardiovascular diseases.
Collapse
Affiliation(s)
- Klaus T Preissner
- Klaus T. Preissner, PhD, Department of Biochemistry, Medical School, Justus-Liebig-University, Friedrichstrasse 24, 35392 Giessen, Germany, Tel.: +49 641 994 7500, E-mail:
| | | |
Collapse
|
107
|
Bonnard T, Law LS, Tennant Z, Hagemeyer CE. Development and validation of a high throughput whole blood thrombolysis plate assay. Sci Rep 2017; 7:2346. [PMID: 28539608 PMCID: PMC5443825 DOI: 10.1038/s41598-017-02498-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 04/11/2017] [Indexed: 12/26/2022] Open
Abstract
The objective of this work was to develop a high throughput assay for testing in vitro the thrombolytic activity using citrated whole blood samples, and to overcome the limitations of currently available techniques. We successfully developed a method that involves forming halo shaped, tissue factor induced, whole blood clots in 96 well plates, and then precisely measuring the thrombolysis process with a spectrophotometer plate reader. We here describe the implementation of this novel method, which we refer to as halo assay, and its validation with plasmin, urokinase and tissue plasminogen activator at different doses. The resulting data is a highly detailed thrombolysis profile, allowing comparison of different fibrinolytic agents. The time point analysis allows kinetic data to be collected and calculated to determine key parameters such as the activation time and the rate of fibrinolysis. We also assessed the capacity of the model to study the effect of clot maturation time on the fibrinolytic rate, an aspect of thrombosis rather unexplored with currently available methods, but of increasing importance in drug development. This novel thrombolysis assay could be an extremely useful research tool; to study the complex process of thrombolysis, and a valuable translational clinical tool; as a screening device to rapidly identify hypo- or hyper-fibrinolysis.
Collapse
Affiliation(s)
- T Bonnard
- NanoBiotechnology Laboratory, Australian Centre for Blood Diseases, Monash University, Melbourne, Australia.,VascularBiotechnology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - L S Law
- VascularBiotechnology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Z Tennant
- NanoBiotechnology Laboratory, Australian Centre for Blood Diseases, Monash University, Melbourne, Australia.,VascularBiotechnology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - C E Hagemeyer
- NanoBiotechnology Laboratory, Australian Centre for Blood Diseases, Monash University, Melbourne, Australia. .,VascularBiotechnology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia. .,RMIT University, Melbourne, Australia.
| |
Collapse
|
108
|
Foley JH, Conway EM. Cross Talk Pathways Between Coagulation and Inflammation. Circ Res 2017; 118:1392-408. [PMID: 27126649 DOI: 10.1161/circresaha.116.306853] [Citation(s) in RCA: 378] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/21/2016] [Indexed: 02/06/2023]
Abstract
Anatomic pathology studies performed over 150 years ago revealed that excessive activation of coagulation occurs in the setting of inflammation. However, it has taken over a century since these seminal observations were made to delineate the molecular mechanisms by which these systems interact and the extent to which they participate in the pathogenesis of multiple diseases. There is, in fact, extensive cross talk between coagulation and inflammation, whereby activation of one system may amplify activation of the other, a situation that, if unopposed, may result in tissue damage or even multiorgan failure. Characterizing the common triggers and pathways are key for the strategic design of effective therapeutic interventions. In this review, we highlight some of the key molecular interactions, some of which are already showing promise as therapeutic targets for inflammatory and thrombotic disorders.
Collapse
Affiliation(s)
- Jonathan H Foley
- From the Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom (J.H.F.); Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom (J.H.F.); and Centre for Blood Research, Department of Medicine, University of British Columbia, Vancouver, Canada (E.M.C.)
| | - Edward M Conway
- From the Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom (J.H.F.); Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom (J.H.F.); and Centre for Blood Research, Department of Medicine, University of British Columbia, Vancouver, Canada (E.M.C.).
| |
Collapse
|
109
|
Jeffery U, LeVine DN. Canine Neutrophil Extracellular Traps Enhance Clot Formation and Delay Lysis. Vet Pathol 2017; 55:116-123. [PMID: 28346125 DOI: 10.1177/0300985817699860] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Autoimmune diseases increase the risk of thrombosis. Neutrophil extracellular traps (NETs) are webs of DNA and protein that may mediate thrombosis in autoimmune diseases. Human and murine studies show NET-releasing neutrophils within a thrombus promote its growth, but it is unclear to what extent NET fragments released into circulation during inflammation are prothrombotic. This study hypothesized that canine NETs promote clot formation and impair lysis even in the absence of neutrophils. NETs were prepared from PMA-stimulated neutrophils and added to fibrinogen and thrombin or to recalcified pooled canine platelet-poor plasma, tissue factor, and tissue plasminogen activator. Clot formation and lysis were measured spectrophotometrically. NETs did not alter fibrin clot formation, but NETs increased maximum clot formation velocity ( P = .001) and delayed lysis ( P = .009) of plasma clots compared with supernatants from nonstimulated neutrophils. DNase digestion of NETs reduced their effect on clot lysis but not maximum clot formation velocity. This suggested impaired lysis was principally mediated by DNA within NETs but that NET proteins were principally responsible for increased speed of clot formation. Previous reports suggested elastase or histones might be responsible for the effect of NETs on clot formation. Elastase activity was greatly reduced by plasma, and addition of histones to plasma did not increase formation velocity, suggesting these proteins were not responsible for increasing maximum formation velocity. This study showed that NETs enhanced clot formation and impaired clot lysis in canine platelet-poor plasma. These in vitro findings suggest both NET proteins and DNA may contribute to thrombosis in inflammatory disease.
Collapse
Affiliation(s)
- Unity Jeffery
- 1 Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Dana N LeVine
- 2 Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| |
Collapse
|
110
|
Ginsburg I, van Heerden PV, Koren E. From amino acids polymers, antimicrobial peptides, and histones, to their possible role in the pathogenesis of septic shock: a historical perspective. J Inflamm Res 2017; 10:7-15. [PMID: 28203100 PMCID: PMC5293372 DOI: 10.2147/jir.s126150] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This paper describes the evolution of our understanding of the biological role played by synthetic and natural antimicrobial cationic peptides and by the highly basic nuclear histones as modulators of infection, postinfectious sequelae, trauma, and coagulation phenomena. The authors discuss the effects of the synthetic polymers of basic poly α amino acids, poly l-lysine, and poly l-arginine on blood coagulation, fibrinolysis, bacterial killing, and blood vessels; the properties of natural and synthetic antimicrobial cationic peptides as potential replacements or adjuncts to antibiotics; polycations as opsonizing agents promoting endocytosis/phagocytosis; polycations and muramidases as activators of autolytic wall enzymes in bacteria, causing bacteriolysis and tissue damage; and polycations and nuclear histones as potential virulence factors and as markers of sepsis, septic shock, disseminated intravasclar coagulopathy, acute lung injury, pancreatitis, trauma, and other additional clinical disorders.
Collapse
Affiliation(s)
- Isaac Ginsburg
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem
| | | | - Erez Koren
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem
| |
Collapse
|
111
|
Promyelocytic extracellular chromatin exacerbates coagulation and fibrinolysis in acute promyelocytic leukemia. Blood 2017; 129:1855-1864. [PMID: 28053193 DOI: 10.1182/blood-2016-09-739334] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/20/2016] [Indexed: 12/28/2022] Open
Abstract
Despite routine treatment of unselected acute promyelocytic leukemia (APL) with all-trans-retinoic acid (ATRA), early death because of hemorrhage remains unacceptably common, and the mechanism underlying this complication remains elusive. We have recently demonstrated that APL cells undergo a novel cell death program, termed ETosis, which involves release of extracellular chromatin. However, the role of promyelocytic extracellular chromatin in APL-associated coagulation remains unclear. Our objectives were to identify the novel role of ATRA-promoted extracellular chromatin in inducing a hypercoagulable and hyperfibrinolytic state in APL and to evaluate its interaction with fibrin and endothelial cells (ECs). Results from a series of coagulation assays have shown that promyelocytic extracellular chromatin increases thrombin and plasmin generation, causes a shortening of plasma clotting time of APL cells, and increases fibrin formation. DNase I but not anti-tissue factor antibody could inhibit these effects. Immunofluorescence staining showed that promyelocytic extracellular chromatin and phosphatidylserine on APL cells provide platforms for fibrin deposition and render clots more resistant to fibrinolysis. Additionally, coincubation assays revealed that promyelocytic extracellular chromatin is cytotoxic to ECs, converting them to a procoagulant phenotype. This cytotoxity was blocked by DNase I by 20% or activated protein C by 31%. Our current results thus delineate the pathogenic role of promyelocytic extracellular chromatin in APL coagulopathy. Furthermore, the remaining coagulation disturbance in high-risk APL patients after ATRA administration may be treatable by intrinsic pathway inhibition via accelerating extracellular chromatin degradation.
Collapse
|
112
|
Tanka-Salamon A, Komorowicz E, Szabó L, Tenekedjiev K, Kolev K. Free Fatty Acids Modulate Thrombin Mediated Fibrin Generation Resulting in Less Stable Clots. PLoS One 2016; 11:e0167806. [PMID: 27942000 PMCID: PMC5152833 DOI: 10.1371/journal.pone.0167806] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/21/2016] [Indexed: 12/19/2022] Open
Abstract
Upon platelet activation, free fatty acids are released at the stage of thrombus formation, but their effects on fibrin formation are largely unexplored. Our objective was to characterize the kinetic effects of fatty acids on thrombin activity, as well as the structural and mechanical properties of the resultant fibrin clots. Thrombin activity on fibrinogen was followed by turbidimetry and detailed kinetic characterization was performed using a fluorogenic short peptide substrate. The viscoelastic properties of fibrin were measured with rotatory oscillation rheometer, whereas its structure was analyzed with scanning electron microscopy (SEM). In turbidimetric assays of fibrin generation, oleate and stearate at physiologically relevant concentrations (60–600 μM) produced a bell-shaped inhibitory dose response, increasing 10- to 30-fold the time to half-maximal clotting. Oleate inhibited thrombin activity on a short peptide substrate according to a mixed-type inhibitor pattern (a 9-fold increase of the Michaelis constant, Km and a 20% decrease of the catalytic constant), whereas stearate resulted in only a minor (15%) drop in the catalytic constant without any change in the Km. Morphometric analysis of SEM images showed a 73% increase in the median fiber diameter in the presence of stearate and a 20% decrease in the presence of oleate. Concerning the viscoelastic parameters of the clots, storage and loss moduli, maximal viscosity and critical shear stress decreased by 32–65% in the presence of oleate or stearate, but loss tangent did not change indicating decreased rigidity, higher deformability and decreased internal resistance to shear stress. Our study provides evidence that free fatty acids (at concentrations comparable to those reported in thrombi) reduce the mechanical stability of fibrin through modulation of thrombin activity and the pattern of fibrin assembly.
Collapse
Affiliation(s)
- Anna Tanka-Salamon
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Erzsébet Komorowicz
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - László Szabó
- IMEC, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Kiril Tenekedjiev
- Nikola Vaptsarov Naval Academy, Varna, Bulgaria
- Australian Maritime College, University of Tasmania, Newnham, Australia
| | - Krasimir Kolev
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- * E-mail:
| |
Collapse
|
113
|
Pfeiler S, Stark K, Massberg S, Engelmann B. Propagation of thrombosis by neutrophils and extracellular nucleosome networks. Haematologica 2016; 102:206-213. [PMID: 27927771 DOI: 10.3324/haematol.2016.142471] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/17/2016] [Indexed: 12/23/2022] Open
Abstract
Neutrophils, early mediators of the innate immune defense, are recruited to developing thrombi in different types of thrombosis. They amplify intravascular coagulation by stimulating the tissue factor-dependent extrinsic pathway via inactivation of endogenous anticoagulants, enhancing factor XII activation or decreasing plasmin generation. Neutrophil-dependent prothrombotic mechanisms are supported by the externalization of decondensed nucleosomes and granule proteins that together form neutrophil extracellular traps. These traps, either in intact or fragmented form, are causally involved in various forms of experimental thrombosis as first indicated by their role in the enhancement of both microvascular thrombosis during bacterial infection and carotid artery thrombosis. Neutrophil extracellular traps can be induced by interactions of neutrophils with activated platelets; vice versa, these traps enhance adhesion of platelets via von Willebrand factor. Neutrophil-induced microvascular thrombus formation can restrict the dissemination and survival of blood-borne bacteria and thereby sustain intravascular immunity. Dysregulation of this innate immune pathway may support sepsis-associated coagulopathies. Notably, neutrophils and extracellular nucleosomes, together with platelets, critically promote fibrin formation during flow restriction-induced deep vein thrombosis. Neutrophil extracellular traps/extracellular nucleosomes are increased in thrombi and in the blood of patients with different vaso-occlusive pathologies and could be therapeutically targeted for the prevention of thrombosis. Thus, during infections and in response to blood vessel damage, neutrophils and externalized nucleosomes are major promoters of intravascular blood coagulation and thrombosis.
Collapse
Affiliation(s)
- Susanne Pfeiler
- Institut für Laboratoriumsmedizin, Ludwig-Maximilians-Universität, Munich, Germany
| | - Konstantin Stark
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Bernd Engelmann
- Institut für Laboratoriumsmedizin, Ludwig-Maximilians-Universität, Munich, Germany
| |
Collapse
|
114
|
Görög A, Németh K, Szabó L, Mayer B, Silló P, Kolev K, Kárpáti S. Decreased fibrinolytic potential and morphological changes of fibrin structure in dermatitis herpetiformis. J Dermatol Sci 2016; 84:17-23. [DOI: 10.1016/j.jdermsci.2016.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/12/2016] [Accepted: 07/06/2016] [Indexed: 01/27/2023]
|
115
|
Abstract
In recent years, the traditional view of the hemostatic system as being regulated by a coagulation factor cascade coupled with platelet activation has been increasingly challenged by new evidence that activation of the immune system strongly influences blood coagulation and pathological thrombus formation. Leukocytes can be induced to express tissue factor and release proinflammatory and procoagulant molecules such as granular enzymes, cytokines, and damage-associated molecular patterns. These mediators can influence all aspects of thrombus formation, including platelet activation and adhesion, and activation of the intrinsic and extrinsic coagulation pathways. Leukocyte-released procoagulant mediators increase systemic thrombogenicity, and leukocytes are actively recruited to the site of thrombus formation through interactions with platelets and endothelial cell adhesion molecules. Additionally, phagocytic leukocytes are involved in fibrinolysis and thrombus resolution, and can regulate clearance of platelets and coagulation factors. Dysregulated activation of leukocyte innate immune functions thus plays a role in pathological thrombus formation. Modulation of the interactions between leukocytes or leukocyte-derived procoagulant materials and the traditional hemostatic system is an attractive target for the development of novel antithrombotic strategies.
Collapse
|
116
|
Kimball AS, Obi AT, Diaz JA, Henke PK. The Emerging Role of NETs in Venous Thrombosis and Immunothrombosis. Front Immunol 2016; 7:236. [PMID: 27446071 PMCID: PMC4921471 DOI: 10.3389/fimmu.2016.00236] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/02/2016] [Indexed: 12/11/2022] Open
Abstract
Venous thrombosis (VT), a leading cause of morbidity and mortality worldwide, has recently been linked to neutrophil activation and release of neutrophil extracellular traps (NETs) via a process called NETosis. The use of various in vivo thrombosis models and genetically modified mice has more precisely defined the exact role of NETosis in the pathogenesis of VT. Translational large animal VT models and human studies have confirmed the presence of NETs in pathologic VT. Activation of neutrophils, with subsequent NETosis, has also been linked to acute infection. This innate immune response, while effective for bacterial clearance from the host by formation of an intravascular bactericidal "net," also triggers thrombosis. Intravascular thrombosis related to such innate immune mechanisms has been coined immunothrombosis. Dysregulated immunothrombosis has been proposed as a mechanism of pathologic micro- and macrovascular thrombosis in sepsis and autoimmune disease. In this focused review, we will address the dual role of NETs in the pathogenesis of VT and immunothrombosis.
Collapse
Affiliation(s)
- Andrew S Kimball
- Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, Department of Surgery, University of Michigan , Ann Arbor, MI , USA
| | - Andrea T Obi
- Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, Department of Surgery, University of Michigan , Ann Arbor, MI , USA
| | - Jose A Diaz
- Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, Department of Surgery, University of Michigan , Ann Arbor, MI , USA
| | - Peter K Henke
- Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, Department of Surgery, University of Michigan , Ann Arbor, MI , USA
| |
Collapse
|
117
|
NETosis and lack of DNase activity are key factors in Echis carinatus venom-induced tissue destruction. Nat Commun 2016; 7:11361. [PMID: 27093631 PMCID: PMC4838891 DOI: 10.1038/ncomms11361] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 03/17/2016] [Indexed: 12/15/2022] Open
Abstract
Indian Echis carinatus bite causes sustained tissue destruction at the bite site. Neutrophils, the major leukocytes in the early defence process, accumulate at the bite site. Here we show that E. carinatus venom induces neutrophil extracellular trap (NET) formation. The NETs block the blood vessels and entrap the venom toxins at the injection site, promoting tissue destruction. The stability of NETs is attributed to the lack of NETs-degrading DNase activity in E. carinatus venom. In a mouse tail model, mice co-injected with venom and DNase 1, and neutropenic mice injected with the venom, do not develop NETs, venom accumulation and tissue destruction at the injected site. Strikingly, venom-induced mice tail tissue destruction is also prevented by the subsequent injection of DNase 1. Thus, our study suggests that DNase 1 treatment may have a therapeutic potential for preventing the tissue destruction caused by snake venom. The saw-scaled viper venom causes continued tissue damage that may cause death. Here the authors show that the venom attracts neutrophils to the bite site and induces neutrophil extracellular traps that capture venom components causing tissue damage, which can be prevented by enzymatic DNA degradation.
Collapse
|
118
|
Alhamdi Y, Toh CH. The role of extracellular histones in haematological disorders. Br J Haematol 2016; 173:805-11. [PMID: 27062156 DOI: 10.1111/bjh.14077] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/05/2016] [Accepted: 02/06/2016] [Indexed: 12/22/2022]
Abstract
Over the past decades, chromosomal alterations have been extensively investigated for their pathophysiological relevance in haematological malignancies. In particular, epigenetic modifications of intra-nuclear histones are now known as key regulators of healthy cell cycles that have also evolved into novel therapeutic targets for certain blood cancers. Thus, for most haematologists, histones are DNA-chained proteins that are buried deep within chromatin. However, the plot has deepened with recent revelations on the function of histones when unchained and released extracellularly upon cell death or from activated neutrophils as part of neutrophil extracellular traps (NETs). Extracellular histones and NETs are increasingly recognized for profound cytotoxicity and pro-coagulant effects. This article highlights the importance of recognizing this new paradigm of extracellular histones as a key player in host defence through its damage-associated molecular patterns, which could translate into novel diagnostic and therapeutic biomarkers in various haematological and critical disorders.
Collapse
Affiliation(s)
- Yasir Alhamdi
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Cheng-Hock Toh
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.,Roald Dahl Haemostasis & Thrombosis Centre, Royal Liverpool University Hospital, Liverpool, UK
| |
Collapse
|
119
|
Longstaff C, Hogwood J, Gray E, Komorowicz E, Varjú I, Varga Z, Kolev K. Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems. Thromb Haemost 2015; 115:591-9. [PMID: 26632486 DOI: 10.1160/th15-03-0214] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/22/2015] [Indexed: 12/14/2022]
Abstract
Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure.
Collapse
Affiliation(s)
- Colin Longstaff
- Colin Longstaff, Biotherapeutics Group, National Institute for Biological Standards and Control, S Mimms, Herts, EN6 3QG, UK, Tel.: +44 1707 641253, Fax: +44 1707 641050, E-Mail:
| | | | | | | | | | | | | |
Collapse
|
120
|
Gould TJ, Vu TT, Stafford AR, Dwivedi DJ, Kim PY, Fox-Robichaud AE, Weitz JI, Liaw PC. Cell-Free DNA Modulates Clot Structure and Impairs Fibrinolysis in Sepsis. Arterioscler Thromb Vasc Biol 2015; 35:2544-53. [PMID: 26494232 DOI: 10.1161/atvbaha.115.306035] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/30/2015] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Sepsis is characterized by systemic activation of inflammation and coagulation in response to infection. In sepsis, activated neutrophils extrude neutrophil extracellular traps composed of cell-free DNA (CFDNA) that not only trap pathogens but also provide a stimulus for clot formation. Although the effect of CFDNA on coagulation has been extensively studied, much less is known about the impact of CFDNA on fibrinolysis. To address this, we (1) investigated the relationship between CFDNA levels and fibrinolytic activity in sepsis and (2) determined the mechanisms by which CFDNA modulates fibrinolysis. APPROACH AND RESULTS Plasma was collected from healthy and septic individuals, and CFDNA was quantified. Clot lysis assays were performed in plasma and purified systems, and lysis times were determined by monitoring absorbance. Clot morphology was assessed using scanning electron microscopy. Clots formed in plasma from septic patients containing >5 µg/mL CFDNA were dense in structure and resistant to fibrinolysis, a phenomenon overcome by deoxyribonuclease addition. These effects were recapitulated in control plasma supplemented with CFDNA. In a purified system, CFDNA delayed fibrinolysis but did not alter tissue-type plasminogen activator-induced plasmin generation. Using surface plasmon resonance, CFDNA bound plasmin with a Kd value of 4.2±0.3 µmol/L, and increasing concentrations of CFDNA impaired plasmin-mediated degradation of fibrin clots via the formation of a nonproductive ternary complex between plasmin, CFDNA, and fibrin. CONCLUSIONS Our studies suggest that the increased levels of CFDNA in sepsis impair fibrinolysis by inhibiting plasmin-mediated fibrin degradation, thereby identifying CFDNA as a potential therapeutic target for sepsis treatment.
Collapse
Affiliation(s)
- Travis J Gould
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Trang T Vu
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Alan R Stafford
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Dhruva J Dwivedi
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Paul Y Kim
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Alison E Fox-Robichaud
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Jeffrey I Weitz
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada
| | - Patricia C Liaw
- From the Department of Medical Sciences (T.J.G., T.T.V.), Thrombosis and Atherosclerosis Research Institute (T.J.G., T.T.V., A.R.S., D.J.D., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), and Department of Medicine (A.R.S., P.Y.K., A.E.F.-R., J.I.W., P.C.L.), McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
121
|
Engelmann B. Extracellular DNA and histones as thrombus stabiliser. Thromb Haemost 2015; 113:1164. [PMID: 25947938 DOI: 10.1160/th15-05-0375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 05/05/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Bernd Engelmann
- Bernd Engelmann, MD, PhD, Institut für Laboratoriumsmedizin, Ludwigs-Maximilians-Universität, Marchioninistrasse 15, 81377 München, Germany, Tel.: +49 89 440073243, Fax: +49 89 440076220, E-mail:
| |
Collapse
|