1
|
Chowdary P, Agarwal B, Peralta MR, Bhagani S, Lee S, Goldring J, Lipman M, Waqif E, Phillips M, Philippou H, Foley JH, Mutch NJ, Ariëns RAS, Stringer KA, Ricciardi F, Watissée M, Hughes D, Nathwani A, Riddell A, Patch D, Buckley J, De Neef M, Dimber R, Diaz-Garcia C, Patel H, Nandani A, Dissanayake U, Chadwick N, Alkhatip AAAMM, Watkinson P, Raith E, Singh S, Wolff T, Jha R, Brill SE, Bakhai A, Evans A, Gilani F, Gomez K. Nebulized Recombinant Tissue Plasminogen Activator (rt-PA) for Acute COVID-19-Induced Respiratory Failure: An Exploratory Proof-of-Concept Trial. J Clin Med 2023; 12:5848. [PMID: 37762789 PMCID: PMC10531875 DOI: 10.3390/jcm12185848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Acute lung injury in COVID-19 results in diffuse alveolar damage with disruption of the alveolar-capillary barrier, coagulation activation, alveolar fibrin deposition and pulmonary capillary thrombi. Nebulized recombinant tissue plasminogen activator (rt-PA) has the potential to facilitate localized thrombolysis in the alveolar compartment and improve oxygenation. In this proof-of-concept safety study, adults with COVID-19-induced respiratory failure and a <300 mmHg PaO2/FiO2 (P/F) ratio requiring invasive mechanical ventilation (IMV) or non-invasive respiratory support (NIRS) received nebulized rt-PA in two cohorts (C1 and C2), alongside standard of care, between 23 April-30 July 2020 and 21 January-19 February 2021, respectively. Matched historical controls (MHC; n = 18) were used in C1 to explore efficacy. Safety co-primary endpoints were treatment-related bleeds and <1.0-1.5 g/L fibrinogen reduction. A variable dosing strategy with clinical efficacy endpoint and minimal safety concerns was determined in C1 for use in C2; patients were stratified by ventilation type to receive 40-60 mg rt-PA daily for ≤14 days. Nine patients in C1 (IMV, 6/9; NIRS, 3/9) and 26 in C2 (IMV, 12/26; NIRS, 14/26) received nebulized rt-PA for a mean (SD) of 6.7 (4.6) and 9.1(4.6) days, respectively. Four bleeds (one severe, three mild) in three patients were considered treatment related. There were no significant fibrinogen reductions. Greater improvements in mean P/F ratio from baseline to study end were observed in C1 compared with MHC (C1; 154 to 299 vs. MHC; 154 to 212). In C2, there was no difference in the baseline P/F ratio of NIRS and IMV patients. However, a larger improvement in the P/F ratio occurred in NIRS patients (NIRS; 126 to 240 vs. IMV; 120 to 188) and fewer treatment days were required (NIRS; 7.86 vs. IMV; 10.5). Nebulized rt-PA appears to be well-tolerated, with a trend towards improved oxygenation, particularly in the NIRS group. Randomized clinical trials are required to demonstrate the clinical effect significance and magnitude.
Collapse
Affiliation(s)
- Pratima Chowdary
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Banwari Agarwal
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Maria Rita Peralta
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Sanjay Bhagani
- Department of Infectious Diseases, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Simon Lee
- Department of Infectious Diseases, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - James Goldring
- Respiratory Medicine, Royal Free London NHS Foundation Trust, London NW1 2BU, UK
| | - Marc Lipman
- Respiratory Medicine, Royal Free London NHS Foundation Trust, London NW1 2BU, UK
- UCL Respiratory, University College London, London WC1E 6JF, UK;
| | - Emal Waqif
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Mark Phillips
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Helen Philippou
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | | | - Nicola J. Mutch
- Aberdeen Cardiovascular & Diabetes Centre, School of Medicine, Medical Sciences & Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Robert A. S. Ariëns
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Kathleen A. Stringer
- Department of Clinical Pharmacy, College of Pharmacy University of Michigan, Ann Arbor, MI 48109, USA
- Division of Pulmonary and Critical Care Medicine, School of Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Federico Ricciardi
- Department of Statistical Science, University College London, London WC1E 6BT, UK
| | | | - Derralynn Hughes
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Amit Nathwani
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Anne Riddell
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Haemophilia & Thrombosis Laboratory (Health Services Laboratories), Royal Free Hospital, London WC1H 9AX, UK
| | - David Patch
- Department of Hepatology, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Jim Buckley
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Mark De Neef
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Rahul Dimber
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Cecilia Diaz-Garcia
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Honey Patel
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Aarti Nandani
- Clinical Trials Pharmacy, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Upuli Dissanayake
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Nick Chadwick
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Ahmed A. A. M. M. Alkhatip
- Department of Anaesthesia, Birmingham Children’s Hospital, Birmingham B4 6NH, UK
- Department of Anaesthesia, Faculty of Medicine, Beni-Suef University Hospital, Beni-Suef University, Beni-Suef 2721562, Egypt
| | - Peter Watkinson
- NIHR Biomedical Research Centre Oxford, Oxford University Hospitals NHS Trust, University of Oxford, Oxford OX3 9DU, UK
| | - Eamon Raith
- Bloomsbury Institute for Intensive Care Medicine, Department of Experimental and Translational Medicine, University College London, London WC1E 6JF, UK
- Discipline of Acute Care Medicine, School of Medicine, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Suveer Singh
- Department of Respiratory and Critical Care Medicine, Chelsea & Westminster Hospital, London SW10 9NH, UK
- Department of Adult Intensive Care, Royal Brompton Hospital, London SW3 6NP, UK
- Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Tony Wolff
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Rajeev Jha
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
| | - Simon E. Brill
- UCL Respiratory, University College London, London WC1E 6JF, UK;
| | - Ameet Bakhai
- Department of Intensive Care and Anaesthesia, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, London NW3 2PS, UK
| | - Alison Evans
- University College London (UCL)/University College London Hospitals NHS Trust (UCLH) Joint Research Office, London WC1E 6BT, UK; (A.E.)
| | - Farhat Gilani
- University College London (UCL)/University College London Hospitals NHS Trust (UCLH) Joint Research Office, London WC1E 6BT, UK; (A.E.)
| | - Keith Gomez
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London NW3 2QG, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| |
Collapse
|
2
|
Chowdary P, Hamid C, Slatter D, Morris R, Foley JH, Gomez K, Brodkin E, Fox TA, Gatt A, McVey JH. Impaired platelet-dependent thrombin generation associated with thrombocytopenia is improved by prothrombin complex concentrates in vitro. Res Pract Thromb Haemost 2020; 4:334-342. [PMID: 32110765 PMCID: PMC7040546 DOI: 10.1002/rth2.12310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 12/06/2019] [Accepted: 12/12/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Impaired thrombin generation (TG) in patients with acquired coagulopathy, is due to low coagulation factors and thrombocytopenia. The latter is typically treated with platelet transfusions and the former with plasma and occasionally with prothrombin complex concentrates (PCCs). We hypothesized that manipulating the concentrations of coagulation factors might result in restoration of platelet-dependent TG over and above that of simple replacement therapy. OBJECTIVE To investigate the influence of PCCs on impaired TG secondary to thrombocytopenia. METHODS TG was evaluated by thrombin generation assay using a thrombocytopenia model in which normal plasma samples with varying platelet counts (20-300 × 109/L) were spiked with PCCs (25%-150% increase in plasma PCC levels). RESULTS PCCs and platelets significantly increased TG in a dose-dependent manner in vitro. Two-way repeated measures of analysis of variance showed variance in peak height, area under the curve, time to peak, and velocity. This variance explained, respectively, by levels of PCC was 47, 59, 25 and 53%; by platelet count was 45, 28, 44, and 14%; by the combination was 80, 67, 70, and 62% variance; and a combination with additional interaction was 91, 84, 76, and 68%. TG at a platelet count 40 × 109/L with an approximate 25% increase in PCC concentration was similar to TG at 150 × 109/L. Similarly, patient samples spiked ex vivo with PCCs also showed highly significant improvements in TG. CONCLUSIONS Impaired TG of thrombocytopenia is improved by PCCs, supporting the need for additional studies in complex coagulopathies characterized by mild to moderate thrombocytopenia and abnormal coagulation.
Collapse
Affiliation(s)
- Pratima Chowdary
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
- Department of HaematologyUniversity College LondonLondonUK
| | - Colleen Hamid
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
- Department of HaematologyUniversity College LondonLondonUK
| | - David Slatter
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | - Jonathan H. Foley
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
| | - Keith Gomez
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
- Department of HaematologyUniversity College LondonLondonUK
| | - Edgar Brodkin
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
| | - Thomas A. Fox
- Katharine Dormandy Haemophilia and Thrombosis CentreRoyal Free HospitalLondonUK
- Department of HaematologyUniversity College LondonLondonUK
| | - Alex Gatt
- Department of PathologyFaculty of Medicine and SurgeryUniversity of MaltaMsidaMalta
| | - John H. McVey
- School of Biosciences & MedicineUniversity of SurreyGuildfordUK
| |
Collapse
|
3
|
Affiliation(s)
- J H Foley
- Freeline Therapeutics, Stevenage, UK
| | - E M Conway
- Centre for Blood Research, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
4
|
Foley KA, Groome PA, Feldman-Stewart D, Brundage MD, Foley JH, McArdle S, Mackillop WJ. Measuring the Quality of Personal Care in Patients Undergoing Radiotherapy for Prostate Cancer. Clin Oncol (R Coll Radiol) 2017; 29:827-834. [PMID: 29032863 DOI: 10.1016/j.clon.2017.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 07/20/2017] [Accepted: 08/14/2017] [Indexed: 11/15/2022]
Abstract
AIMS To describe the quality of the non-technical component of the care (personal care) of patients receiving radical radiotherapy for prostate cancer and to identify elements of personal care that should be priorities for quality improvement. MATERIALS AND METHODS One hundred and eight patients undergoing radiotherapy for localised prostate cancer completed a self-administered questionnaire that asked them to rate the importance of 143 non-technical elements of care and to rate the quality of their own care with respect to each element. The elements that a patient rated as both 'very important' and less than 'very good' were deemed to be his priorities for improvement. The priorities of the population were established by ranking the elements based on the percentage of patients who identified them as a priority (importance/quality analysis). RESULTS The response rate was 65%. The percentage of elements rated 'very good' varied from patient to patient: median 79% (interquartile range 69-92%). The percentage of elements rated either 'very good' or 'good' was higher: median 96% (interquartile range 86-98%). Nonetheless, almost every patient rated at least some elements of his care as less than optimal, regardless of the cut-off point used to define optimal quality. Patients assigned their lowest quality ratings to elements relating to the quality of the treatment environment and comprehensiveness of additional services available to them. However, patients rated most of these elements as relatively unimportant, and importance/quality analysis identified elements of care relating to communication of information about the disease and its treatment as the highest priorities for quality improvement. CONCLUSIONS Most patients rated most elements of their personal care as very good, but almost all were able to identify some elements that were less than optimal. When ratings of quality were integrated with ratings of importance, elements relating to communication emerged as the patients' highest priorities for quality improvement.
Collapse
Affiliation(s)
- K A Foley
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Kingston, Ontario, Canada; Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - P A Groome
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Kingston, Ontario, Canada; Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - D Feldman-Stewart
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Kingston, Ontario, Canada; Department of Oncology, Queen's University, Kingston, Ontario, Canada
| | - M D Brundage
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Kingston, Ontario, Canada; Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada; Department of Oncology, Queen's University, Kingston, Ontario, Canada; Cancer Centre of Southeastern Ontario, Kingston, Ontario, Canada
| | - J H Foley
- Freeline Therapeutics Limited, London, UK
| | - S McArdle
- Cancer Centre of Southeastern Ontario, Kingston, Ontario, Canada
| | - W J Mackillop
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Kingston, Ontario, Canada; Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada; Department of Oncology, Queen's University, Kingston, Ontario, Canada; Cancer Centre of Southeastern Ontario, Kingston, Ontario, Canada.
| |
Collapse
|
5
|
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
|
6
|
Abstract
The diverse mechanisms by which the plasmin(ogen) system is involved in human physiology and pathology are constantly being delineated. For many years, the plasmin(ogen) system was chiefly known as the system responsible for vascular fibrinolysis. Although this is an important function of the plasmin(ogen) system, we now recognize that plasmin(ogen) is critically important as a mediator of inflammation and the innate immune system, which impacts upon a diverse set of mechanisms underlying the pathologies of many diseases. The current review focuses on recent developments in plasmin(ogen) system activation and regulation and how dysregulation of this finely tuned system may contribute to inflammatory disease (atherosclerosis), impaired wound healing, and infection.
Collapse
Affiliation(s)
- Jonathan H Foley
- Freeline Therapeutics, Royal Free Hospital, London, United Kingdom
| |
Collapse
|
7
|
Aleshnick M, Foley JH, Keating FK, Butenas S. Procoagulant activity in stored units of red blood cells. Biochem Biophys Res Commun 2016; 474:680-685. [PMID: 27150627 DOI: 10.1016/j.bbrc.2016.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/01/2016] [Indexed: 01/08/2023]
Abstract
The procoagulant activity (PA) of stored units of red blood cells (RBC) increases over time, which is related to the expression/exposure of tissue factor (TF). However, there is a discrepancy between the TF measured and changes in PA observed, suggesting that other blood components contribute to this activity. Our goal was to evaluate changes in PA of stored RBCs and to determine possible contributors to it. RBC units from 4 healthy donors were prepared and stored at 4 °C. On selected days, RBC aliquots were reconstituted with autologous plasma and tested in the thromboelastography assay. Corresponding supernatants were tested in a clotting assay. For all donors, the clotting time (CT) of reconstituted RBC units decreased from ∼3000-4000s on day 1 to ∼1000-1600s on day 30, with the most dramatic changes occurring between days 1 and 5. Anti-TF antibody slightly prolonged the CT. The concentration of TF did not change significantly over time and was within the range of 0.3-2.3 pM. Bovine lactadherin (LTD) prolonged the CT of the RBC (by 2.4-3.4-fold in days 3-5 and by 1.3-1.8-fold at day 30). Anti-TF antibody together with LTD had a cumulative effect on the CT prolongation. CT of supernatants responded to both anti-TF and anti-FXIa antibodies. Three contributors to the PA of stored RBC were identified, i.e. FXIa in solution and phosphatidylserine and TF exposed on blood cells and microparticles. Failure of LTD and antibodies to completely eliminate PA suggests that other components of blood could contribute to it.
Collapse
Affiliation(s)
- Maya Aleshnick
- Department of Biochemistry, University of Vermont, 360 South Park Drive, Room 235A, Colchester, VT 05446, USA.
| | - Jonathan H Foley
- Department of Biochemistry, University of Vermont, 360 South Park Drive, Room 235A, Colchester, VT 05446, USA.
| | - Friederike K Keating
- Department of Medicine, University of Vermont, 360 South Park Drive, Room 235A, Colchester, VT 05446, USA.
| | - Saulius Butenas
- Department of Biochemistry, University of Vermont, 360 South Park Drive, Room 235A, Colchester, VT 05446, USA.
| |
Collapse
|
8
|
|
9
|
Ouellet E, Foley JH, Conway EM, Haynes C. Hi-Fi SELEX: A High-Fidelity Digital-PCR Based Therapeutic Aptamer Discovery Platform. Biotechnol Bioeng 2016; 112:1506-22. [PMID: 25727321 DOI: 10.1002/bit.25581] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 02/14/2015] [Indexed: 12/30/2022]
Abstract
Current technologies for aptamer discovery typically leverage the systematic evolution of ligands by exponential enrichment (SELEX) concept by recursively panning semi-combinatorial ssDNA or RNA libraries against a molecular target. The expectation is that this iterative selection process will be sufficiently stringent to identify a candidate pool of specific high-affinity aptamers. However, failure of this process to yield promising aptamers is common, due in part to (i) limitations in library designs, (ii) retention of non-specific aptamers during screening rounds, (iii) excessive accumulation of amplification artifacts, and (iv) the use of screening criteria (binding affinity) that does not reflect therapeutic activity. We report a new selection platform, High-Fidelity (Hi-Fi) SELEX, that introduces fixed-region blocking elements to safeguard the functional diversity of the library. The chemistry of the target-display surface and the composition of the equilibration solvent are engineered to strongly inhibit non-specific retention of aptamers. Partition efficiencies approaching 10(6) are thereby realized. Retained members are amplified in Hi-Fi SELEX by digital PCR in a manner that ensures both elimination of amplification artifacts and stoichiometric conversion of amplicons into the single-stranded library required for the next selection round. Improvements to aptamer selections are first demonstrated using human α-thrombin as the target. Three clinical targets (human factors IXa, X, and D) are then subjected to Hi-Fi SELEX. For each, rapid enrichment of ssDNA aptamers offering an order-nM mean equilibrium dissociation constant (Kd) is achieved within three selection rounds, as quantified by a new label-free qPCR assay reported here. Therapeutic candidates against factor D are identified.
Collapse
|
10
|
Foley JH, Walton BL, Aleman MM, O'Byrne AM, Lei V, Harrasser M, Foley KA, Wolberg AS, Conway EM. Complement Activation in Arterial and Venous Thrombosis is Mediated by Plasmin. EBioMedicine 2016; 5:175-82. [PMID: 27077125 PMCID: PMC4816834 DOI: 10.1016/j.ebiom.2016.02.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/20/2022] Open
Abstract
Thrombus formation leading to vaso-occlusive events is a major cause of death, and involves complex interactions between coagulation, fibrinolytic and innate immune systems. Leukocyte recruitment is a key step, mediated partly by chemotactic complement activation factors C3a and C5a. However, mechanisms mediating C3a/C5a generation during thrombosis have not been studied. In a murine venous thrombosis model, levels of thrombin–antithrombin complexes poorly correlated with C3a and C5a, excluding a central role for thrombin in C3a/C5a production. However, clot weight strongly correlated with C5a, suggesting processes triggered during thrombosis promote C5a generation. Since thrombosis elicits fibrinolysis, we hypothesized that plasmin activates C5 during thrombosis. In vitro, the catalytic efficiency of plasmin-mediated C5a generation greatly exceeded that of thrombin or factor Xa, but was similar to the recognized complement C5 convertases. Plasmin-activated C5 yielded a functional membrane attack complex (MAC). In an arterial thrombosis model, plasminogen activator administration increased C5a levels. Overall, these findings suggest plasmin bridges thrombosis and the immune response by liberating C5a and inducing MAC assembly. These new insights may lead to the development of strategies to limit thrombus formation and/or enhance resolution. Thrombin is not a major direct contributor to C5a generation during venous thrombosis in mice. Plasmin, a protease generated in response to thrombin generation and fibrin deposition, efficiently cleaves C5 to C5a. In an arterial thrombosis model, administration of a plasminogen activator augments C5a plasma levels. Plasmin participates in immunothrombosis, liberating chemotactic C5a and inducing assembly of the procoagulant C5b-9.
Venous and arterial thrombosis are major causes of death and morbidity. Leukocytes are early and active participants in thrombus formation, recruited partly by complement factor C5a. We examined how C5a is generated in the setting of thrombosis. In venous thrombosis in mice, we show that thrombin, a key clot-promoting enzyme, is not a major contributor to C5a generation. Rather, plasmin, a fibrinolytic enzyme formed in response to thrombin generation and clot formation, efficiently generates C5a. The findings were validated in an arterial thrombosis model in mice. These insights may be valuable in developing therapeutic strategies to limit thrombus formation.
Collapse
Key Words
- Complement
- FDP, fibrin degradation product
- FeCl3, ferric chloride
- Fibrinolysis
- IL-8, interleukin-8
- IVC, inferior vena cava
- Leukocytes
- MAC, membrane attack complex
- MCP1-1, monocyte chemoattracant protein-1
- NETs, neutrophil extracellular traps
- PAR1, protease activated receptor 1
- PPACK, Phe-Pro-Arg-chloromethylketone
- R751, arginine 751
- TAT, thrombin antithrombin
- Thrombin
- Thrombosis
- VFKck, Val-Phe-Lys-chloromethylketone
- VWF, von Willebrand factor
- tPA, tissue-type plasminogen activator
Collapse
Affiliation(s)
- Jonathan H. Foley
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
- Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom
| | - Bethany L. Walton
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Maria M. Aleman
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Alice M. O'Byrne
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
| | - Victor Lei
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
| | - Micaela Harrasser
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
| | - Kimberley A. Foley
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Canada
| | - Alisa S. Wolberg
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Edward M. Conway
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
- Corresponding author at: Centre for Blood Research, 4306-2350 Health Sciences Mall, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.Centre for Blood Research4306-2350 Health Sciences MallUniversity of British ColumbiaVancouverBCV6T 1Z3Canada
| |
Collapse
|
11
|
Foley JH, Kim PY, Hendriks D, Morser J, Gils A, Mutch NJ. Evaluation of and recommendation for the nomenclature of the CPB2 gene product (also known as TAFI and proCPU): communication from the SSC of the ISTH. J Thromb Haemost 2015; 13:2277-8. [PMID: 27028102 DOI: 10.1111/jth.13168] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 09/26/2015] [Indexed: 11/26/2022]
Affiliation(s)
- J H Foley
- Research Department of Haematology, University College London and Katherine Dormandy Haemophilia Centre and Thrombosis Unit, London, UK
| | - P Y Kim
- Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, ON, Canada
| | - D Hendriks
- Laboratory for Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - J Morser
- Division of Hematology, School of Medicine, Stanford University, Stanford, CA, USA
| | - A Gils
- Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Leuven, Belgium
| | - N J Mutch
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| |
Collapse
|
12
|
Foley JH, Peterson EA, Lei V, Wan LW, Krisinger MJ, Conway EM. Interplay between fibrinolysis and complement: plasmin cleavage of iC3b modulates immune responses. J Thromb Haemost 2015; 13:610-8. [PMID: 25556624 DOI: 10.1111/jth.12837] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 12/18/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND The plasmin(ogen) and complement systems are simultaneously activated at sites of tissue injury, participating in hemostasis, wound healing, inflammation and immune surveillance. In particular, the C3 proteolytic fragment, iC3b, and its degradation product C3dg, which is generated by cleavage by factor I (FI) and the cofactor complement receptor CR1, are important in bridging innate and adaptive immunity. Via a thioester (TE) bond, iC3b and C3dg covalently tag pathogens, modulating phagocytosis and adaptive immune responses. OBJECTIVE To examine plasmin-mediated proteolysis of iC3b, and to evaluate the functional consequences, comparing the effects with products generated by FI/CR1 cleavage of iC3b. METHODS Dose-dependent and time-dependent plasmin-mediated cleavage of iC3b were characterized by analytical gel electrophoresis. The properties of the resultant TE bond-containing fragments on phagocytosis and induction of pro-inflammatory cytokines were measured in cell culture systems. RESULTS At low concentrations, plasmin effectively cleaves iC3b, but at numerous previously undescribed sites, giving rise to novel C3c-like and C3dg-like moieties, the latter of which retain the TE bond. When attached to zymosan or erythrocytes and exposed to THP-1 macrophages, the C3dg-like proteins behave almost identically to the bona fide C3dg, yielding less phagocytosis as compared with the opsonin iC3b, and more macrophage secretion of the pro-inflammatory cytokine, IL-12. CONCLUSION Plasmin cleavage of iC3b provides a complement regulatory pathway that is as efficient as FI/CR1 but does not require a cellular cofactor.
Collapse
Affiliation(s)
- J H Foley
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada; Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | | |
Collapse
|
13
|
Yu K, Lai BFL, Foley JH, Krisinger MJ, Conway EM, Kizhakkedathu JN. Modulation of complement activation and amplification on nanoparticle surfaces by glycopolymer conformation and chemistry. ACS Nano 2014; 8:7687-7703. [PMID: 25106451 DOI: 10.1021/nn504186b] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The complement system plays an integral part of a host's innate immunity, and its activation is highly dependent on the chemistry and structure of a "foreign" target surface. We determined that the conformational state of glycopolymer chains, defined by the grafting density (chains/nm(2)), on the nanoparticle (NP) surface acts as a "molecular switch" for complement activation and amplification, and the protein corona on the NP surface dictates this process. A grafting density threshold was determined, below which minimal complement activation was observed and above which substantial complement activation was detected. The glycopolymer-grafted NPs activated complement via the alternative pathway. The chemical structure of pendent sugar units on the grafted polymer was also an important determinant for complement activation. NPs grafted with glucose-containing polymer activated complement at a lower grafting density compared to NPs grafted with galactose-containing polymer. Analysis of complement activation products C3a and SC5b-9 followed a similar pattern. Complement activation on the NP surface was independent of particle size or concentration for a given conformational state of grafted polymer. To gain insight into a putative surface-dependent mechanism of complement activation, we determined the nature of adsorbed protein corona on various NPs through quantitative mass spectrometry. Elevated levels of two pro-complement proteins, factors B and C3, present on the NP surface grafted with glycopolymer chains at high grafting density compared to low grafting density surface, may be responsible for its complement activity. Galactose polymer modified NPs adsorbed more of the negative regulator of complement, factor H, than the glucose surface, providing an explanation for its lower level of complement activation.
Collapse
Affiliation(s)
- Kai Yu
- Centre for Blood Research and Department of Pathology & Laboratory Medicine and ‡Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z3, Canada
| | | | | | | | | | | |
Collapse
|
14
|
Niżankowska-Jędrzejczyk A, Almeida FR, Lowe AA, Kania A, Nastałek P, Mejza F, Foley JH, Niżankowska-Mogilnicka E, Undas A. Modulation of inflammatory and hemostatic markers in obstructive sleep apnea patients treated with mandibular advancement splints: a parallel, controlled trial. J Clin Sleep Med 2014; 10:255-62. [PMID: 24634622 DOI: 10.5664/jcsm.3522] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
STUDY OBJECTIVE Obstructive sleep apnea (OSA) is associated with systemic inflammation and a hypercoagulable state. The current study aim was to investigate whether mandibular advancement splint (MAS) therapy affects inflammatory and hemostatic parameters in patients with mild-to-moderate OSA. METHODS Twenty-two patients with mild-to-moderate OSA and 16 control subjects were studied. OSA subjects were treated with a titratable MAS for 6 months. Baseline plasma C-reactive protein, interleukin-1β, interleukin-10, interleukin-6, P-selectin, fibrinogen, D-dimer, plasminogen activator inhibitor-1 (PAI-1), thrombin-antithrombin complex, activated thrombin-activatable fibrinolysis inhibitor (TAFIa), 6-keto-PGF1α, glucose, and fibrin clot lysis time (CLT) were measured in all subjects. After 3 months of MAS therapy, measurements were repeated for the 22 patients, and after 6 months all measurements were repeated for all study subjects. RESULTS MAS treatment reduced significantly AHI at 3 months (24 vs 13.1/h) and further improved it at 6 months (13.1 vs 7.05/h). Compared with controls, OSA subjects had a significant higher baseline mean levels of fibrinogen, TAFIa, 6-keto-PGF1α, and glucose. MAS treatment significantly improved levels of IL-1β, D-dimer, TAFIa, and CLT. Despite residual apneas, MAS treatment group presented similar measured homeostatic and inflammatory levels to controls except for glucose. CONCLUSION Treatment with MAS in mild-to-moderate OSA subjects improves the inflammatory profile and homeostatic markers. CITATION Niżankowska-Jędrzejczyk A; Almeida FR; Lowe AA; Kania A; Nastałek P; Mejza F; Foley JH; Niżankowska-Mogilnicka E; Undas A. Modulation of inflammatory and hemostatic markers in obstructive sleep apnea patients treated with mandibular advancement splints: a parallel, controlled trial.
Collapse
Affiliation(s)
| | - Fernanda R Almeida
- Department of Oral Health Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alan A Lowe
- Department of Oral Health Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aleksander Kania
- Department of Pulmonology, Jagiellonian University Medical College, Krakow, Poland
| | - Paweł Nastałek
- Department of Pulmonology, Jagiellonian University Medical College, Krakow, Poland
| | - Filip Mejza
- Department of Pulmonology, Jagiellonian University Medical College, Krakow, Poland
| | - Jonathan H Foley
- Department of Biochemistry, University of Vermont, Burlington, VT
| | | | - Anetta Undas
- Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland
| |
Collapse
|
15
|
Rea CJ, Foley JH, Okaisabor O, Sørensen B. FXIII: mechanisms of action in the treatment of hemophilia A. J Thromb Haemost 2014; 12:159-68. [PMID: 24354581 DOI: 10.1111/jth.12478] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 11/24/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hemophilia is characterized by abnormal thrombin generation and impaired clot stability. FXIII promotes clot stability and may be a useful adjunct treatment for hemophilia. OBJECTIVES This study examined the clot stabilizing effects and safety of supra-physiological FXIII and explored the mechanisms via which FXIII exerts its effects in hemophilia A. METHODS The effects of FXIII on clot formation and stability were examined using a thromboelastometry assay and blood samples collected from six patients with severe hemophilia A. The effect of FXIII on clot formation was also assessed using a murine model. The mechanisms of FXIII action in hemophilia A were explored by measuring thrombin generation, rates of FXIII activation and effects on clot permeability, pore size and fibrin fiber diameter. RESULTS This study demonstrates that supra-physiological concentrations of FXIII stabilize clots in blood from patients with hemophilia by improving resistance to t-Pa-induced fibrinolysis even at low concentrations of FVIII (FVIII< 0.1 IU mL⁻¹, P < 0.05, anova). Addition of FXIII stoichiometrically up-regulates its activation, correcting the fibrin clot structure, reducing clot permeability and facilitating thrombin generation; FXIII significantly shortens ttPeak and lagtime (P < 0.05) in FVIII-deficient plasma, providing a novel explanation for its positive effects on clot stability and structure. The murine model indicates that supra-physiological FXIII is tolerated and does not significantly alter time to clot formation. CONCLUSION The effects of FXIII on clot stability and physical clot structure are seen at low concentrations of FVIII, indicating that FXIII could be a useful treatment in a variety of clinical scenarios.
Collapse
Affiliation(s)
- C J Rea
- King's College London School of Medicine, London, UK
| | | | | | | |
Collapse
|
16
|
Abstract
Fibrinolysis is initiated when the zymogen plasminogen is converted to plasmin via the action of plasminogen activators. Proteolytic cleavage of fibrin by plasmin generates C-terminal lysine residues capable of binding both plasminogen and the plasminogen activator, thereby stimulating plasminogen activator-mediated plasminogen activation and propagating fibrinolysis. This positive feedback mechanism is regulated by activated thrombin activatable fibrinolysis inhibitor (TAFIa), which cleaves C-terminal lysine residues from the fibrin surface, thereby decreasing its cofactor activity. TAFI can be activated by thrombin alone, but the rate of activation is accelerated when in complex with thrombomodulin. Plasmin is also known to activate TAFI. TAFIa has no known physiologic inhibitors and consequently, its primary regulatory mechanism involves its intrinsic thermal instability. The rate of TAFI activation and stability of the active form, TAFIa, function in maintaining its concentration above the threshold value required to down-regulate fibrinolysis. Although all methods to quantify TAFI or TAFIa have their limitations, epidemiologic studies have indicated that elevated TAFI levels are correlated with an increased risk of venous thrombosis. Major efforts have been made to develop TAFI inhibitors that can either directly interfere with TAFIa activity or impair its activation. However, the anti-inflammatory properties of TAFIa might complicate the development and application of a TAFIa inhibitor that aims to increase the efficiency of thrombolytic therapy.
Collapse
Affiliation(s)
- J H Foley
- Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
| | | | | | | |
Collapse
|
17
|
Foley JH, Orfeo T, Undas A, McLean KC, Bernstein IM, Rivard GE, Mann KG, Everse SJ, Brummel-Ziedins KE. From principle to practice: bridging the gap in patient profiling. PLoS One 2013; 8:e54728. [PMID: 23372761 PMCID: PMC3556038 DOI: 10.1371/journal.pone.0054728] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 12/14/2012] [Indexed: 12/20/2022] Open
Abstract
The standard clinical coagulation assays, activated partial thromboplastin time (aPTT) and prothrombin time (PT) cannot predict thrombotic or bleeding risk. Since thrombin generation is central to haemorrhage control and when unregulated, is the likely cause of thrombosis, thrombin generation assays (TGA) have gained acceptance as "global assays" of haemostasis. These assays generate an enormous amount of data including four key thrombin parameters (lag time, maximum rate, peak and total thrombin) that may change to varying degrees over time in longitudinal studies. Currently, each thrombin parameter is averaged and presented individually in a table, bar graph or box plot; no method exists to visualize comprehensive thrombin generation data over time. To address this need, we have created a method that visualizes all four thrombin parameters simultaneously and can be animated to evaluate how thrombin generation changes over time. This method uses all thrombin parameters to intrinsically rank individuals based on their haemostatic status. The thrombin generation parameters can be derived empirically using TGA or simulated using computational models (CM). To establish the utility and diverse applicability of our method we demonstrate how warfarin therapy (CM), factor VIII prophylaxis for haemophilia A (CM), and pregnancy (TGA) affects thrombin generation over time. The method is especially suited to evaluate an individual's thrombotic and bleeding risk during "normal" processes (e.g pregnancy or aging) or during therapeutic challenges to the haemostatic system. Ultimately, our method is designed to visualize individualized patient profiles which are becoming evermore important as personalized medicine strategies become routine clinical practice.
Collapse
Affiliation(s)
- Jonathan H. Foley
- Department of Biochemistry, University of Vermont, Burlington, Vermont, United States of America
| | - Thomas Orfeo
- Department of Biochemistry, University of Vermont, Burlington, Vermont, United States of America
| | - Anetta Undas
- Institute of Cardiology, Jagiellonian University School of Medicine, Krakow, Poland
| | - Kelley C. McLean
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington, Vermont, United States of America
| | - Ira M. Bernstein
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington, Vermont, United States of America
| | - Georges-Etienne Rivard
- Department of Hematology-Oncology, Centre Hospitalier Universitaire Sainte-Justine, Montréal, Canada
| | - Kenneth G. Mann
- Department of Biochemistry, University of Vermont, Burlington, Vermont, United States of America
| | - Stephen J. Everse
- Department of Biochemistry, University of Vermont, Burlington, Vermont, United States of America
| | | |
Collapse
|
18
|
Gissel M, Orfeo T, Foley JH, Butenas S. Effect of BAX499 aptamer on tissue factor pathway inhibitor function and thrombin generation in models of hemophilia. Thromb Res 2012; 130:948-55. [PMID: 22951415 DOI: 10.1016/j.thromres.2012.08.299] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/02/2012] [Accepted: 08/14/2012] [Indexed: 11/26/2022]
Abstract
INTRODUCTION In hemophilia, thrombin generation is significantly suppressed due to decreased factor (F)X activation. Clinical studies and experiments with transgenic mice have suggested that the severity of hemophilia is substantially reduced by tissue factor pathway inhibitor (TFPI) deficiency. METHODS We evaluated the effect of TFPI antagonist aptamer BAX499 (formerly ARC19499) on TFPI function in purified systems and on thrombin generation and clot formation in plasma and blood. RESULTS BAX499 effectively neutralized TFPI inhibition of FXa and FXa dependent inhibition of TF/FVIIa by TFPI. BAX499 did not inhibit FXa or TF/FVIIa when used up to 500 nM. In the synthetic coagulation proteome with TFPI at its mean physiologic concentration, BAX499 at 1 - 10nM increased thrombin generation triggered with 5 pM relipidated TF in a concentration-dependent manner. In severe hemophilia A or B models using the synthetic coagulation proteome, the addition of BAX499 at 5 nM increased thrombin generation to the levels observed in normal control. Thrombin generation measured in induced hemophilia B plasma required ~100nM BAX499 to restore thrombin levels to those seen in untreated plasma. In induced hemophilia B whole blood, BAX499 repaired the clotting time but failed to appreciably impact the propagation phase of thrombin generation. CONCLUSION These data suggest that inhibition of TFPI by BAX499 may have potential for hemophilia treatment but requires further study in blood-based hemophilia systems.
Collapse
Affiliation(s)
- Matthew Gissel
- Department of Biochemistry, University of Vermont, Colchester, Vermont 05446, United States
| | | | | | | |
Collapse
|
19
|
Abstract
Coagulation factor I (fibrinogen) plays an essential role in the hemostatic system by bridging activated platelets and being the key substrate for thrombin in establishing a consolidating fibrin network. Fibrinogen is synthesized in the liver and the plasma concentration is 1 to 5-4.0 g/L. During recent 10 years, fibrinogen has been recognized to play an important role in controlling hemorrhage. Dilutional coagulopathy induced by colloid plasma expanders is characterized by fibrinogen deficiency and dysfunctional fibrin polymerization. Trauma and use of extracorporeal circulation is also known to reduce levels of fibrinogen. A series of laboratory experiments and experimental animal studies have suggested fibrinogen as a potent hemostatic agent. These data are supported by retrospective surveys as well as a series of prospective proof of principal clinical trials. This article provides a description of the biochemistry and mechanisms of fibrinogen as well as the etiology for developing fibrinogen deficiency. Furthermore, it summarizes laboratory and experimental data on the role of fibrinogen in dilutional coagulopathy and addresses laboratory monitoring issues. Finally, it lists retrospective and prospective studies, which have been designed to assess the clinical efficacy and safety of hemostatic intervention with fibrinogen concentrate.
Collapse
Affiliation(s)
- Benny Sørensen
- Haemostasis Research Unit, Centre for Haemostasis and Thrombosis, Guy's and St Thomas's NHS Foundation Trust, London, United Kingdom.
| | | | | | | | | | | |
Collapse
|
20
|
Owczarek D, Undas A, Foley JH, Nesheim ME, Jabłonski K, Mach T. Activated thrombin activatable fibrinolysis inhibitor (TAFIa) is associated with inflammatory markers in inflammatory bowel diseases TAFIa level in patients with IBD. J Crohns Colitis 2012; 6:13-20. [PMID: 22261523 DOI: 10.1016/j.crohns.2011.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 06/11/2011] [Accepted: 06/12/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND Thrombin activatable fibrinolysis inhibitor (TAFI) has been reported to be involved in the pathogenesis and progression of inflammatory bowel disease (IBD). Activated TAFI (TAFIa) attenuates fibrinolysis by cleaving C-terminal lysine residues thus down-regulating plasminogen activation. To date, no reports on TAFIa in IBD have been published. METHODS Plasma levels of TAFIa were measured using a functional assay in 55 consecutive patients with ulcerative colitis (UC) and 50 with Crohn's disease (CD). Associations of TAFIa with disease activity, hemostatic variables and inflammatory markers were assessed. RESULTS Plasma TAFIa was higher in CD patients than in those with UC. The disease activity correlated positively with TAFIa levels in the UC group, but not in the CD group. In UC patients, there were positive correlations of TAFIa with white blood cells, C-reactive protein and fibrinogen and an inverse correlation with albumin. In the CD group, a positive correlation was shown for C-reactive protein, fibrinogen and platelet count, while a negative correlation was noted for albumin. CONCLUSIONS This study is the first to show that TAFIa is increased in CD patients compared with UC and its levels are associated with inflammatory markers in both forms of IBD. These findings fit in the hypothesis that TAFIa may be a marker of active IBD, and in particular of active UC.
Collapse
Affiliation(s)
- Danuta Owczarek
- Department of Gastroenterology, Hepatology and Infectious Diseases Jagiellonian University School of Medicine, Krakow, Poland.
| | | | | | | | | | | |
Collapse
|
21
|
|
22
|
Foley JH, Butenas S, Mann KG, Brummel-Ziedins KE. Measuring the mechanical properties of blood clots formed via the tissue factor pathway of coagulation. Anal Biochem 2012; 422:46-51. [PMID: 22266209 DOI: 10.1016/j.ab.2011.12.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 11/28/2022]
Abstract
Thrombelastography (TEG) is a method that is used to conduct global assays that monitor fibrin formation and fibrinolysis and platelet aggregation in whole blood. The purpose of this study was to use a well-characterized tissue factor (Tf) reagent and contact pathway inhibitor (corn trypsin inhibitor, CTI) to develop a reproducible thrombelastography assay. In this study, blood was collected from 5 male subjects (three times). Clot formation was initiated in whole blood with 5 pM Tf in the presence of CTI, and fibrinolysis was induced by adding tissue plasminogen activator (tPA). Changes in viscoelasticity were then monitored by TEG. In quality control assays, our Tf reagent, when used at 5 pM, induced coagulation in whole blood in 3.93 ± 0.23 min and in plasma in 5.12 ± 0.23 min (n=3). In TEG assays, tPA significantly decreased clot strength (maximum amplitude, MA) in all individuals but had no effect on clot time (R time). The intraassay variability (CVa<10%) for R time, angle, and MA suggests that these parameters reliably describe the dynamics of fibrin formation and degradation in whole blood. Our Tf reagent reproducibly induces coagulation, making it an ideal tool to quantify the processes that contribute to mechanical clot strength in whole blood.
Collapse
Affiliation(s)
- J H Foley
- Department of Biochemistry, University of Vermont, Burlington, Colchester, VT 05446, USA
| | | | | | | |
Collapse
|
23
|
Abstract
Individuals with haemophilia A exhibit bleeding tendencies that are not always predicted by their factor (F)VIII level. It has been suggested that bleeding in haemophilia is due not only to defective prothrombin activation but also aberrant fibrinolysis. Thrombin activatable fibrinolysis inhibitor (TAFI) activation was measured in tissue factor (TF)-initiated blood coagulation in blood samples of 28 haemophiliacs and five controls. Reactions were quenched over time with FPRck and citrate and assayed for TAFIa and thrombin-antithrombin (TAT). The TAFIa potential (TP), TAFI activation rate and the TAFIa level at 20 min (TAFIa(20 min)) was extracted from the TAFI activation progress curve. In general, the time course of TAFI activation follows thrombin generation regardless of FVIII activity and as expected the rate of TAFI activation and TP decreases as FVIII decreases. The magnitude of TP was similar among the control subjects and subjects with <11% FVIII. In severe subjects with <1% FVIII at the time of blood collection, the TAFIa(20 min) was inversely and significantly correlated with haemarthrosis (-0.77, P = 0.03) and total bleeds (-0.75, P = 0.03). In all cases, TAFIa(20 min) was more strongly correlated with bleeding than TAT levels at 20 min. Overall, this study shows that TAFI activation in whole blood can be quantified and related to the clinical bleeding phenotype. Measuring TAFIa along with thrombin generation can potentially be useful to evaluate the differential bleeding phenotype in haemophilia A.
Collapse
Affiliation(s)
- J H Foley
- The Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | | | | | | |
Collapse
|
24
|
Foley JH, Cook PF, Nesheim ME. Kinetics of activated thrombin-activatable fibrinolysis inhibitor (TAFIa)-catalyzed cleavage of C-terminal lysine residues of fibrin degradation products and removal of plasminogen-binding sites. J Biol Chem 2011; 286:19280-6. [PMID: 21467042 DOI: 10.1074/jbc.m110.215061] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Partial digestion of fibrin by plasmin exposes C-terminal lysine residues, which comprise new binding sites for both plasminogen and tissue-type plasminogen activator (tPA). This binding increases the catalytic efficiency of plasminogen activation by 3000-fold compared with tPA alone. The activated thrombin-activatable fibrinolysis inhibitor (TAFIa) attenuates fibrinolysis by removing these residues, which causes a 97% reduction in tPA catalytic efficiency. The aim of this study was to determine the kinetics of TAFIa-catalyzed lysine cleavage from fibrin degradation products and the kinetics of loss of plasminogen-binding sites. We show that the k(cat) and K(m) of Glu(1)-plasminogen (Glu-Pg)-binding site removal are 2.34 s(-1) and 142.6 nm, respectively, implying a catalytic efficiency of 16.21 μm(-1) s(-1). The corresponding values of Lys(77)/Lys(78)-plasminogen (Lys-Pg)-binding site removal are 0.89 s(-1) and 96 nm implying a catalytic efficiency of 9.23 μm(-1) s(-1). These catalytic efficiencies of plasminogen-binding site removal by TAFIa are the highest of any TAFIa-catalyzed reaction with a biological substrate reported to date and suggest that plasmin-modified fibrin is a primary physiological substrate for TAFIa. We also show that the catalytic efficiency of cleavage of all C-terminal lysine residues, whether they are involved in plasminogen binding or not, is 1.10 μm(-1) s(-1). Interestingly, this value increases to 3.85 μm(-1) s(-1) in the presence of Glu-Pg. These changes are due to a decrease in K(m). This suggests that an interaction between TAFIa and plasminogen comprises a component of the reaction mechanism, the plausibility of which was established by showing that TAFIa binds both Glu-Pg and Lys-Pg.
Collapse
Affiliation(s)
- Jonathan H Foley
- Department of Biochemistry, Queen's University, Kingston, Ontario, Canada
| | | | | |
Collapse
|
25
|
Abstract
BACKGROUND Abnormal thrombin generation is considered the key defect in hemophilia. Conventional treatment seeks to correct this using coagulation factor replacement or bypassing agents, for example recombinant factor VIIa (rFVIIa). Previous studies demonstrate abnormal FXIII activation in patients with hemophilia. FXIII activation is essential for formation of structurally normal, stable clots. OBJECTIVES The present study challenges the hypothesis that in hemophilia the use of plasma-derived FXIII (pdFXIII) in combination with rFVIIa will produce a greater improvement in clot stability than promotion of thrombin generation alone. METHODS Fourteen individuals with severe hemophila A were enrolled. Whole blood was spiked ex vivo with buffer, rFVIIa (2 μg mL(-1)) or rFVIIa (2 μg mL(-1)) plus pdFXIII (10 μg mL(-1)). Whole blood thromboelastometry assessed clot stability, after activation with tissue factor (TF) (0.15 pm) plus tissue-type plasminogen activator (tPa) (2 nm). The primary outcome measure of clot stability was area under the elasticity curve (AUEC). RESULTS The combination of pdFXIII and rFVIIa significantly improved clot stability as measured by AUEC (P < 0.05) compared with rFVIIa alone. CONCLUSION The use of pdFXIII resulted in superior clot stability compared with solely enhancing thrombin generation and we suggest that increasing thrombin generation alone fails to fully correct dysregulation of clot-stabilizing mechanisms associated with bleeding disorders. Hemorrhage control in hemophilia may be improved using clot stabilizing drugs. FXIII shows potential as a novel agent.
Collapse
Affiliation(s)
- C J Rea
- Haemostasis Research Unit, Guy's & St Thomas' NHS Foundation Trust and King's College London School of Medicine, London, UK
| | | | | | | |
Collapse
|
26
|
Wright TG, Singh VK, Li JJ, Foley JH, Miller F, Jia Z, Elliott BE. Increased production and secretion of HGF alpha-chain and an antagonistic HGF fragment in a human breast cancer progression model. Int J Cancer 2009; 125:1004-15. [PMID: 19415747 DOI: 10.1002/ijc.24364] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Invasive human breast carcinomas frequently coexpress increased hepatocyte growth factor (HGF) and its receptor Met, suggesting that establishment of an autocrine HGF loop is important in malignant disease. This study examines the expression patterns of HGF and Met activation during tumorigenesis and metastasis using a MCF10A-based model of Ha-Ras-induced human breast cancer progression. Deregulation of cadherin-based cell-cell adhesions, decreased expression of cytokeratins 8/18 and increased activity of matrix metalloproteinases such as MMP-2 occurs in premalignant and malignant (metastatic) cell lines compared to the parental nonmalignant cell line. Compared to the benign parent cell line, premalignant and malignant cell lines exhibit increased secretion of full length HGF alpha-chain and elevated Met tyrosine phosphorylation in complete medium. Interestingly, the premalignant and malignant cells also secrete a approximately 55 kDa HGF fragment. Epitope mapping of the approximately 55 kDa HGF fragment supports the presence of the N-terminal domain of the HGF alpha-chain with a truncation in the C-terminal domain. The approximately 55 kDa HGF fragment shows mobility in SDS-PAGE faster than HGF alpha-chain, but slightly slower than NK4, a previously established full antagonist of HGF. The separated approximately 55 kDa HGF fragment binds to animmobilized Met-IgG fusion protein, and inhibits both HGF/Met-IgG binding and HGF-induced Met-tyrosine phosphorylation. These results are the first demonstration of an antagonistic approximately 55 kDa HGF fragment secreted during breast carcinoma progression, which may have a negative regulatory effect on HGF signaling in premalignant breast epithelial cells.
Collapse
Affiliation(s)
- Theodore G Wright
- Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
27
|
Foley JH, Nesheim ME. Soluble thrombomodulin partially corrects the premature lysis defect in FVIII-deficient plasma by stimulating the activation of thrombin activatable fibrinolysis inhibitor. J Thromb Haemost 2009; 7:453-9. [PMID: 19087221 DOI: 10.1111/j.1538-7836.2008.03261.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Previous work by others has shown that premature clot lysis occurs in plasmas deficient in components of the intrinsic pathway, due to a failure to activate thrombin activatable fibrinolysis inhibitor (TAFI). This suggests the hypothesis that bleeding in hemophilia is due not only to defective coagulation but also enhanced fibrinolysis. These studies were carried out to quantify the extent of TAFI activation over time in normal plasma (NP) and factor VIII deficient plasma (FVIII-DP) and to determine whether soluble thrombomodulin (sTM) can correct the lysis defect in FVIII-DP. METHODS The time courses of TAFI activation in both NP and FVIII-DP were monitored after clotting with thrombin, PCPS and Ca(2+), +/- sTM. Clotting and lysis were measured turbidometrically and TAFIa using a functional assay. RESULTS Premature lysis that occurs in FVIII-DP is corrected by mixing deficient plasma with 10% NP. However, this does not fully correct the defect in TAFI activation. FVIII-DP must be mixed with up to 50% NP to attain the same TAFIa potential as NP. In FVIII-DP, sTM can correct the defect in TAFIa-dependent prolongation of lysis at low tPA concentrations and partially correct this defect at high tPA concentrations. CONCLUSIONS TAFI activation increases as the concentration of FVIII increases. FVIII at a level of 10% fully corrects the lysis defect in spite of the extent of TAFI activation being only one half that obtained with 100% FVIII. In addition, sTM increases TAFI activation sufficiently to correct the premature lysis defect in FVIII-DP.
Collapse
Affiliation(s)
- J H Foley
- Department of Biochemistry, Queen's University, Kingston, ON, Canada
| | | |
Collapse
|
28
|
Foley JH, Kim P, Nesheim ME. Thrombin-activable fibrinolysis inhibitor zymogen does not play a significant role in the attenuation of fibrinolysis. J Biol Chem 2008; 283:8863-7. [PMID: 18252711 DOI: 10.1074/jbc.m800127200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activated thrombin-activable fibrinolysis inhibitor (TAFIa) plays a significant role in the prolongation of fibrinolysis. During fibrinolysis, plasminogen is activated to plasmin, which lyses a clot by cleaving fibrin after selected arginine and lysine residues. TAFIa attenuates fibrinolysis by removing the exposed C-terminal lysine residues. It was recently reported that TAFI zymogen possesses sufficient carboxypeptidase activity to attenuate fibrinolysis through a mechanism similar to TAFIa. Here, we show with a recently developed TAFIa assay that when thrombin is used to clot TAFI-deficient plasma supplemented with TAFI, there is some TAFI activation. The extent of activation was dependent upon the concentration of zymogen present in the plasma, and lysis times were prolonged by TAFIa in a concentration-dependent manner. Potato tuber carboxypeptidase inhibitor, an inhibitor of TAFIa but not TAFI, abolished the prolongation of lysis in TAFI-deficient plasma supplemented with TAFI zymogen. In addition, TAFIa but not TAFI catalyzed release of plasminogen bound to soluble fibrin degradation products. The data presented confirm that TAFI zymogen is effective in cleaving a small substrate but does not play a role in the attenuation of fibrinolysis because of its inability to cleave plasmin-modified fibrin degradation products.
Collapse
Affiliation(s)
- Jonathan H Foley
- Departments of Biochemistry and Medicine, Queen's University, Kingston, Ontario, Canada
| | | | | |
Collapse
|
29
|
Lawler EG, Foley JH. A formula for determining linen life. Hospitals 1967; 41:114-117. [PMID: 6047338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|