1
|
Kolyadko VN, Layzer JM, Perry K, Sullenger BA, Krishnaswamy S. An RNA aptamer exploits exosite-dependent allostery to achieve specific inhibition of coagulation factor IXa. Proc Natl Acad Sci U S A 2024; 121:e2401136121. [PMID: 38985762 PMCID: PMC11260126 DOI: 10.1073/pnas.2401136121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 06/06/2024] [Indexed: 07/12/2024] Open
Abstract
Hemostasis relies on a reaction network of serine proteases and their cofactors to form a blood clot. Coagulation factor IXa (protease) plays an essential role in hemostasis as evident from the bleeding disease associated with its absence. RNA aptamers specifically targeting individual coagulation factors have potential as anticoagulants and as probes of the relationship between structure and function. Here, we report X-ray structures of human factor IXa without a ligand bound to the active site either in the apo-form or in complex with an inhibitory aptamer specific for factor IXa. The aptamer binds to an exosite in the catalytic domain and allosterically distorts the active site. Our studies reveal a conformational ensemble of IXa states, wherein large movements of Trp215 near the active site drive functional transitions between the closed (aptamer-bound), latent (apo), and open (substrate-bound) states. The latent state of the apo-enzyme may bear on the uniquely poor catalytic activity of IXa compared to other coagulation proteases. The exosite, to which the aptamer binds, has been implicated in binding VIIIa and heparin, both of which regulate IXa function. Our findings reveal the importance of exosite-driven allosteric modulation of IXa function and new strategies to rebalance hemostasis for therapeutic gain.
Collapse
Affiliation(s)
- Vladimir N. Kolyadko
- Division of Hematology, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA19104
| | | | - Kay Perry
- Northeastern Collaborative Access Team, Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL60439
| | | | - Sriram Krishnaswamy
- Division of Hematology, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA19104
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| |
Collapse
|
2
|
Yu H, Kumar S, Frederiksen JW, Kolyadko VN, Pitoc G, Layzer J, Yan A, Rempel R, Francis S, Krishnaswamy S, Sullenger BA. Aptameric hirudins as selective and reversible EXosite-ACTive site (EXACT) inhibitors. Nat Commun 2024; 15:3977. [PMID: 38730234 PMCID: PMC11087511 DOI: 10.1038/s41467-024-48211-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
Potent and selective inhibition of the structurally homologous proteases of coagulation poses challenges for drug development. Hematophagous organisms frequently accomplish this by fashioning peptide inhibitors combining exosite and active site binding motifs. Inspired by this biological strategy, we create several EXACT inhibitors targeting thrombin and factor Xa de novo by linking EXosite-binding aptamers with small molecule ACTive site inhibitors. The aptamer component within the EXACT inhibitor (1) synergizes with and enhances the potency of small-molecule active site inhibitors by many hundred-fold (2) can redirect an active site inhibitor's selectivity towards a different protease, and (3) enable efficient reversal of inhibition by an antidote that disrupts bivalent binding. One EXACT inhibitor, HD22-7A-DAB, demonstrates extraordinary anticoagulation activity, exhibiting great potential as a potent, rapid onset anticoagulant to support cardiovascular surgeries. Using this generalizable molecular engineering strategy, selective, potent, and rapidly reversible EXACT inhibitors can be created against many enzymes through simple oligonucleotide conjugation for numerous research and therapeutic applications.
Collapse
Affiliation(s)
- Haixiang Yu
- Department of Surgery, Duke University, Durham, NC, USA
| | - Shekhar Kumar
- Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Vladimir N Kolyadko
- Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - George Pitoc
- Department of Surgery, Duke University, Durham, NC, USA
| | | | - Amy Yan
- Department of Surgery, Duke University, Durham, NC, USA
| | - Rachel Rempel
- Department of Surgery, Duke University, Durham, NC, USA
| | - Samuel Francis
- Department of Emergency Medicine, Duke University Hospital, Durham, NC, USA
| | - Sriram Krishnaswamy
- Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Bruce A Sullenger
- Department of Surgery, Duke University, Durham, NC, USA.
- Departments of Pharmacology & Cancer Biology and Biomedical Engineering, Duke University, Durham, NC, USA.
| |
Collapse
|
3
|
Yu H, Frederiksen J, Sullenger BA. Applications and future of aptamers that achieve rapid-onset anticoagulation. RNA (NEW YORK, N.Y.) 2023; 29:455-462. [PMID: 36697262 PMCID: PMC10019365 DOI: 10.1261/rna.079503.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In this short Perspective, we discuss the history of, and recent progress toward, the development of aptamers that can serve as rapid onset anticoagulants during cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), and catheter-based diagnostic and interventional procedures, several million of which are performed each year worldwide. Aptamer anticoagulants provide potent and antidote-controllable anticoagulation and have low immunogenicity. New methods of aptamer isolation and engineering have not only improved the quality of aptamers, but also accelerated their development. Unfortunately, no aptamer identified to date can produce an anticoagulant effect as potent as that produced by unfractionated heparin (UFH), the standard anticoagulant for CPB. We have suggested several possible strategies to amplify the anticoagulant potency of existing aptamer anticoagulants.
Collapse
Affiliation(s)
- Haixiang Yu
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - James Frederiksen
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Bruce A Sullenger
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| |
Collapse
|
4
|
Gray BP, Kelly L, Steen-Burrell KA, Layzer JM, Rempel RE, Nimjee SM, Cooley BC, Tarantal AF, Sullenger BA. Rapid molecular imaging of active thrombi in vivo using aptamer-antidote probes. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 31:440-451. [PMID: 36817726 PMCID: PMC9930157 DOI: 10.1016/j.omtn.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Pathological blood clotting, or thrombosis, limits vital blood flow to organs; such deprivation can lead to catastrophic events including myocardial infarction, pulmonary embolism, and ischemic stroke. Prompt restoration of blood flow greatly improves outcomes. We explored whether aptamers could serve as molecular imaging probes to rapidly detect thrombi. An aptamer targeting thrombin, Tog25t, was found to rapidly localize to and visualize pre-existing clots in the femoral and jugular veins of mice using fluorescence imaging and, when circulating, was able to image clots as they form. Since free aptamer is quickly cleared from circulation, contrast is rapidly developed, allowing clot visualization within minutes. Moreover, administration of an antidote oligonucleotide further enhanced contrast development, causing the unbound aptamer to clear within 5min while impacting the clot-bound aptamer more slowly. These findings suggest that aptamers can serve as imaging agents for rapid detection of thrombi in acute care and perioperative settings.
Collapse
Affiliation(s)
- Bethany Powell Gray
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Linsley Kelly
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Juliana M. Layzer
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rachel E. Rempel
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Shahid M. Nimjee
- Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Brian C. Cooley
- Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7525, USA
| | - Alice F. Tarantal
- Departments of Pediatrics and Cell Biology and Human Anatomy, School of Medicine, and California National Primate Research Center, University of California Davis, Davis, CA 95616-8542, USA
| | - Bruce A. Sullenger
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
- Departments of Pharmacology & Cancer Biology and Biomedical Engineering, Duke University, Durham, NC 27710, USA
| |
Collapse
|
5
|
Aptamers Regulating the Hemostasis System. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238593. [PMID: 36500686 PMCID: PMC9739204 DOI: 10.3390/molecules27238593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
The hemostasis system is a complex structure that includes the fibrinolysis system, and Yes this is correct coagulation and anticoagulation parts. Due to the multicomponent nature, it becomes relevant to study the key changes in the functioning of signaling pathways, and develop new diagnostic methods and modern drugs with high selectivity. One of the ways to solve this problem is the development of molecular recognition elements capable of blocking one of the hemostasis systems and/or activating another. Aptamers can serve as ligands for targeting specific clinical needs, promising anticoagulants with minor side effects and significant biological activity. Aptamers with several clotting factors and platelet proteins are used for the treatment of thrombosis. This review is focused on the aptamers used for the correction of the hemostasis system, and their structural and functional features. G-rich nucleic acid aptamers, mostly versatile G-quadruplexes, recognize different components of the hemostasis system and are capable of correcting the functioning.
Collapse
|
6
|
Reed CR, Bonadonna D, Otto JC, McDaniel CG, Chabata CV, Kuchibhatla M, Frederiksen J, Layzer JM, Arepally GM, Sullenger BA, Tracy ET. Aptamer-based factor IXa inhibition preserves hemostasis and prevents thrombosis in a piglet model of ECMO. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 27:524-534. [PMID: 35036063 PMCID: PMC8728519 DOI: 10.1016/j.omtn.2021.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022]
Abstract
Extracorporeal membrane oxygenation (ECMO) requires anticoagulation to prevent clotting when the patient’s blood contacts the circuit. Unfractionated heparin (UFH) usually prevents clotting but can cause life-threatening bleeding. An anticoagulant that selectively inhibits the contact activation (intrinsic) pathway while sparing the tissue factor (extrinsic) pathway of coagulation might prevent clotting triggered by the circuit while permitting physiologic coagulation at surgical sites. DTRI-178 is an RNA anticoagulant aptamer conjugated to polyethylene glycol that increases its half-life in circulation. This aptamer is based on a previously described molecule (9.3t) that inhibits intrinsic tenase activity by binding to factor IXa on an exosite. Using a piglet model of pediatric venoarterial (VA) ECMO, we compared thromboprevention and blood loss using a single dose of DTRI-178 versus UFH. In each of five experiments, we subjected two litter-matched piglets, one anticoagulated with DTRI-178 and the other with UFH, to simultaneous 12-h periods of VA ECMO. Both anticoagulants achieved satisfactory and comparable thromboprotection. However, UFH piglets had increased surgical site bleeding and required significantly greater blood transfusion volumes than piglets anticoagulated with DTRI-178. Our results indicate that DTRI-178, an aptamer against factor IXa, may be feasible, safer, and result in fewer transfusions and clinical bleeding events in ECMO.
Collapse
Affiliation(s)
- Christopher R. Reed
- Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
- Corresponding author Christopher R. Reed, MD, Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
| | - Desiree Bonadonna
- Extracorporeal Life Support, Duke University Medical Center, Durham, NC 27710, USA
| | - James C. Otto
- Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
| | | | - Charlene Vongai Chabata
- Departments of Surgery; and Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
| | - Maragatha Kuchibhatla
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27710, USA
| | - James Frederiksen
- Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
| | - Juliana M. Layzer
- Duke University Clinical and Translational Science Institute, Durham, NC 27710, USA
| | - Gowthami M. Arepally
- Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Bruce A. Sullenger
- Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
| | - Elisabeth T. Tracy
- Department of Surgery, Duke University Medical Center and Health System, 2301 Erwin Road, Box 3443, Durham, NC 27710, USA
- Division of Pediatric Surgery, Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
7
|
Gong W, Sun M, Guo X, Liu Y, Li H, Xie L, Li X. Nanowired dual-electrodes surface to monitor cerebral ischemia by current-volt measurements. 3 Biotech 2021; 11:502. [PMID: 34881165 PMCID: PMC8599545 DOI: 10.1007/s13205-021-03048-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/31/2021] [Indexed: 11/27/2022] Open
Abstract
The level of clotting protein 'factor IX' (FIX) is highly associated with cerebral ischemia, and this research work has developed a sensitive detection of FIX on dielectrode sensor by current-volt measurement. Sensing area was grown with zinc oxide nanowire to attach more probe for FIX interaction. Aptamer was utilized as the detection probe and attached on the sensing electrode surface through amine-aldehyde chemical linkage. In addition, biotin-streptavidin interaction was utilized to attach the higher number aptamers on the electrode surface connected with dual-probe station. FIX detection limit was found as 10 fM in the phosphate buffer saline spiked samples and 1:320 dilution of human serum. The linear ranges were as 10 fM to 100 pM and 1:320 to 1:80, respectively. With a good determination co-efficient [y = 2.6813x - 3.8467; R 2 = 0.9479] this biosensing strategy helps to quantify FIX and monitor the condition of cerebral ischemia.
Collapse
Affiliation(s)
- Wei Gong
- Department of Neurology 2, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Meilin Sun
- Department of Neurology 4, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Xiaoling Guo
- Department of Neurology, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Yalin Liu
- Department of Neurology 2, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Hongsheng Li
- Department of Neurology 2, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Lanlan Xie
- Department of Neurology 2, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| | - Xipeng Li
- Department of Neurology 2, Xingtai People’s Hospital, Xingtai, 054001 Hebei China
| |
Collapse
|
8
|
In silico structural analysis of truncated 2’ fluoro-RNA aptamer: Elucidating EGF-1 and EGF-2 binding domains on factor IX protein. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.10.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
9
|
Overview of the Therapeutic Potential of Aptamers Targeting Coagulation Factors. Int J Mol Sci 2021; 22:ijms22083897. [PMID: 33918821 PMCID: PMC8069679 DOI: 10.3390/ijms22083897] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022] Open
Abstract
Aptamers are single-stranded DNA or RNA sequences that bind target molecules with high specificity and affinity. Aptamers exhibit several notable advantages over protein-based therapeutics. Aptamers are non-immunogenic, easier to synthesize and modify, and can bind targets with greater affinity. Due to these benefits, aptamers are considered a promising therapeutic candidate to treat various conditions, including hematological disorders and cancer. An active area of research involves developing aptamers to target blood coagulation factors. These aptamers have the potential to treat cardiovascular diseases, blood disorders, and cancers. Although no aptamers targeting blood coagulation factors have been approved for clinical use, several aptamers have been evaluated in clinical trials and many more have demonstrated encouraging preclinical results. This review summarized our knowledge of the aptamers targeting proteins involved in coagulation, anticoagulation, fibrinolysis, their extensive applications as therapeutics and diagnostics tools, and the challenges they face for advancing to clinical use.
Collapse
|
10
|
Application of Piezo-Based Measuring System for Evaluation of Nucleic Acid-Based Drugs Influencing the Coagulation. SENSORS 2019; 20:s20010152. [PMID: 31881749 PMCID: PMC6982813 DOI: 10.3390/s20010152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/15/2019] [Accepted: 12/21/2019] [Indexed: 11/16/2022]
Abstract
During open-heart surgery, the status of hemostasis has to be constantly monitored to quickly and reliably detect bleeding or coagulation disorders. In this study, a novel optimized piezo-based measuring system (PIEZ) for rheological monitoring of hemostasis was established. The applicability of the PIEZ for the evaluation of nucleic acid-based drugs influencing coagulation was analyzed. Thrombin aptamers such as NU172 might be used during extracorporeal circulation (ECC) in combination with a reduced heparin concentration or for patients with heparin-induced thrombocytopenia (HIT). Therefore, the effect of the coagulation inhibiting thrombin aptamer NU172 and the abrogation by its complementary antidote sequence (AD) were investigated by this rheological PIEZ system. After the addition of different NU172 concentrations, the coagulation of fresh human blood was analyzed under static conditions and using an in vitro rotation model under dynamic conditions (simulating ECC). The clotting times (CTs) detected by PIEZ were compared to those obtained with a medical reference device, a ball coagulometer. Additionally, after the circulation of blood samples for 30 min at 37 °C, blood cell numbers, thrombin markers (thrombin-antithrombin III (TAT) and fibrinopeptide A (FPA)) and a platelet activation marker (β-thromboglobulin (β-TG)) were analyzed by enzyme-linked immunosorbent assays (ELISAs). The increase of NU172 concentration resulted in prolonged CTs, which were comparable between the reference ball coagulometer and the PIEZ, demonstrating the reliability of the new measuring system. Moreover, by looking at the slope of the linear regression of the viscous and elastic components, PIEZ also could provide information on the kinetics of the coagulation reaction. The shear viscosity at the end of the measurements (after 300 s) was indicative of clot firmness. Furthermore, the PIEZ was able to detect the abrogation of coagulation inhibition after the equimolar addition of NU172 aptamer´s AD. The obtained results showed that the established PIEZ is capable to dynamically measure the hemostasis status in whole blood and can be applied to analyze nucleic acid-based drugs influencing the coagulation.
Collapse
|
11
|
Stobb MT, Monroe DM, Leiderman K, Sindi SS. Assessing the impact of product inhibition in a chromogenic assay. Anal Biochem 2019; 580:62-71. [PMID: 31091429 DOI: 10.1016/j.ab.2019.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 12/30/2022]
Abstract
Chromogenic substrates (CS) are synthetic substrates used to monitor the activity of a target enzyme. It has been reported that some CSs display competitive product inhibition with their target enzyme. Thus, in assays where enzyme activity is continuously monitored over long periods of time, the product inhibition may significantly interfere with the reactions being monitored. Despite this knowledge, it is rare for CSs to be directly incorporated into mathematical models that simulate these assays. This devalues the predictive power of the models. In this study, we examined the interactions between a single enzyme, coagulation factor Xa, and its chromogenic substrate. We developed, and experimentally validated, a mathematical model of a chromogenic assay for factor Xa that explicitly included product inhibition from the CS. We employed Bayesian inference, in the form of Markov-Chain Monte Carlo, to estimate the strength of the product inhibition and other sources of uncertainty such as pipetting error and kinetic rate constants. Our model, together with carefully calibrated biochemistry experiments, allowed for full characterization of the strength and impact of product inhibition in the assay. The effect of CS product inhibition in more complex reaction mixtures was further explored using mathematical models.
Collapse
Affiliation(s)
- Michael T Stobb
- Department of Applied Mathematics, University of California, Merced, 5200 North Lake Road, Merced, CA, 95340, USA
| | - Dougald M Monroe
- Hematology/Oncology, 8202B Mary Ellen Jones Building, Campus Box 7035, Chapel Hill, NC, 27599-7035, USA
| | - Karin Leiderman
- Department of Applied Mathematics and Statistics, Colorado School of Mines, 1500 Illinois St, Golden, CO, 80401, USA.
| | - Suzanne S Sindi
- Department of Applied Mathematics, University of California, Merced, 5200 North Lake Road, Merced, CA, 95340, USA
| |
Collapse
|
12
|
Moreno A, Pitoc GA, Ganson NJ, Layzer JM, Hershfield MS, Tarantal AF, Sullenger BA. Anti-PEG Antibodies Inhibit the Anticoagulant Activity of PEGylated Aptamers. Cell Chem Biol 2019; 26:634-644.e3. [PMID: 30827937 PMCID: PMC6707742 DOI: 10.1016/j.chembiol.2019.02.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/17/2018] [Accepted: 01/31/2019] [Indexed: 02/06/2023]
Abstract
Biopharmaceuticals have become increasingly attractive therapeutic agents and are often PEGylated to enhance their pharmacokinetics and reduce their immunogenicity. However, recent human clinical trials have demonstrated that administration of PEGylated compounds can evoke anti-PEG antibodies. Considering the ubiquity of PEG in commercial products and the presence of pre-existing anti-PEG antibodies in patients in large clinical trials evaluating a PEG-modified aptamer, we investigated how anti-PEG antibodies effect the therapeutic activities of PEGylated RNA aptamers. We demonstrate that anti-PEG antibodies can directly bind to and inhibit anticoagulant aptamer function in vitro and in vivo. Moreover, in parallel studies we detected the presence of anti-PEG antibodies in nonhuman primates after a single administration of a PEGylated aptamer. Our results suggest that anti-PEG antibodies can limit the activity of PEGylated drugs and potentially compromise the activity of otherwise effective therapeutic agents.
Collapse
Affiliation(s)
- Angelo Moreno
- Department of Molecular Genetics and Microbiology graduate program, Duke University, Durham, NC, USA,Department of Surgery, Duke University, Durham, NC, USA
| | | | - Nancy J. Ganson
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Juliana M. Layzer
- Department of Surgery, Duke University, Durham, NC, USA,Duke Clinical and Translational Science Institute, Durham, NC, USA
| | | | - Alice F. Tarantal
- Departments of Pediatrics and Cell Biology and Human Anatomy, School of Medicine, NHLBI Center for Gene Transfer for Heart, Lung, and Blood Disease, and California National Primate Research Center, University of California, Davis, CA, USA
| | - Bruce A. Sullenger
- Department of Molecular Genetics and Microbiology graduate program, Duke University, Durham, NC, USA,Department of Surgery, Duke University, Durham, NC, USA,Contact Info: Corresponding Author and Lead Contact:
| |
Collapse
|
13
|
Abstract
PURPOSE OF REVIEW Since the selection of the first thrombin-binding aptamer in 1992, the use of nucleic acid aptamers to target specific coagulation factors has emerged as a valuable approach for generating novel anticoagulant and procoagulant therapeutics. Herein, we highlight the most recent discoveries involving application of aptamers for those purposes. RECENT FINDINGS Learning from the successes and pitfalls of the FIXa-targeting aptamer pegnivacogin in preclinical and clinical studies, the latest efforts to develop antidote-controllable anticoagulation strategies for cardiopulmonary bypass that avoid unfractionated heparin involve potentiation of the exosite-binding factor X (FX)a aptamer 11F7t by combination with either a small molecule FXa catalytic site inhibitor or a thrombin aptamer. Recent work has also focused on identifying aptamer inhibitors of contact pathway factors such as FXIa and kallikrein, which may prove to be well tolerated and effective antithrombotic agents in certain clinical settings. Finally, new approaches to develop procoagulant aptamers to control bleeding associated with hemophilia and other coagulopathies involve targeting activated protein C and tissue plasminogen activator. SUMMARY Overall, these recent findings exemplify the versatility of aptamers to modulate a variety of procoagulant and anticoagulant factors, along with their capacity to be used complementarily with other aptamers or drugs for wide-ranging applications.
Collapse
|
14
|
Bala J, Chinnapaiyan S, Dutta RK, Unwalla H. Aptamers in HIV research diagnosis and therapy. RNA Biol 2018; 15:327-337. [PMID: 29431588 PMCID: PMC5927724 DOI: 10.1080/15476286.2017.1414131] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/07/2017] [Accepted: 12/03/2017] [Indexed: 12/30/2022] Open
Abstract
Aptamers are high affinity single-stranded nucleic acid or protein ligands which exhibit specificity and avidity comparable to, or exceeding that of antibodies and can be generated against most targets. The functionality of aptamers is based on their unique tertiary structure, complexity and their ability to attain unique binding pockets by folding. Aptamers are selected in vitro by a process called Systematic Evolution of Ligands by Exponential enrichment (SELEX). The Kd values for the selected aptamer are often in the picomolar to low nanomolar range. Stable and nontoxic aptamers could be selected for a wide range of ligands including small molecules to large proteins. Aptamers have shown tremendous potential and have found multipurpose application in the field of therapeutic, diagnostic, biosensor and bio-imaging. While their mechanism of action can be similar to that of monoclonal antibodies, aptamers provide additional advantages in terms of production cost, simpler regulatory approval and lower immunogenicity as they are synthesized chemically. Human immunodeficiency virus (HIV) is the primary cause of acquired immune deficiency syndrome (AIDS), which causes significant morbidity and mortality with a significant consequent decrease in the quality of patient's lives. While cART has led to good viral control, people living with HIV now suffer from non-HIV comorbidities due to viral protein expression that cannot be controlled by cART. Hence pathophysiological mechanisms that govern these comorbidities with a focus on therapies that neutralize these HIV effects gained increased attention. Recent advances in HIV/AIDS research have identified several molecular targets and for the development of therapeutic and diagnostic using aptamers against HIV/AIDS. This review presents recent advances in aptamers technology for potential application in HIV diagnostics and therapeutics towards improving the quality of life of people living with HIV.
Collapse
Affiliation(s)
- Jyoti Bala
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Srinivasan Chinnapaiyan
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Rajib Kumar Dutta
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Hoshang Unwalla
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| |
Collapse
|
15
|
Steen Burrell KA, Layzer J, Sullenger BA. A kallikrein-targeting RNA aptamer inhibits the intrinsic pathway of coagulation and reduces bradykinin release. J Thromb Haemost 2017; 15:1807-1817. [PMID: 28632925 PMCID: PMC5818257 DOI: 10.1111/jth.13760] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Indexed: 01/29/2023]
Abstract
Essentials Kallikrein amplifies contact activation and is a potential target for preventing thrombosis. We developed and characterized a kallikrein aptamer using convergent evolution and kinetic assays. Kall1-T4 prolongs intrinsic clotting time by inhibiting factor XIIa-mediated prekallikrein activation. Kall1-T4 decreases high-molecular-weight kininogen cleavage and bradykinin release. SUMMARY Background Plasma kallikrein is a serine protease that plays an integral role in many biological processes, including coagulation, inflammation, and fibrinolysis. The main function of kallikrein in coagulation is the amplification of activated factor XII (FXIIa) production, which ultimately leads to thrombin generation and fibrin clot formation. Kallikrein is generated by FXIIa-mediated cleavage of the zymogen prekallikrein, which is usually complexed with the non-enzymatic cofactor high molecular weight kininogen (HK). HK also serves as a substrate for kallikrein to generate the proinflammatory peptide bradykinin (BK). Interestingly, prekallikrein-deficient mice are protected from thrombotic events while retaining normal hemostatic capacity. Therefore, therapeutic targeting of kallikrein may provide a safer alternative to traditional anticoagulants with anti-inflammatory benefits. Objectives To isolate and characterize an RNA aptamer that binds to and inhibits plasma kallikrein, and to elucidate its mechanism of action. Methods and Results Using convergent Systematic Evolution of Ligands by Exponential Enrichment (SELEX), we isolated an RNA aptamer that targets kallikrein. This aptamer, Kall1-T4, specifically binds to both prekallikrein and kallikrein with similar subnanomolar binding affinities, and dose-dependently prolongs fibrin clot formation in an activated partial thromboplastin time (APTT) coagulation assay. In a purified in vitro system, Kall1-T4 inhibits the reciprocal activation of prekallikrein and FXII primarily by reducing the rate of FXIIa-mediated prekallikrein activation. Additionally, Kall1-T4 significantly reduces kallikrein-mediated HK cleavage and subsequent BK release. Conclusions We have isolated a specific and potent inhibitor of prekallikrein/kallikrein activity that serves as a powerful tool for further elucidating the role of kallikrein in thrombosis and inflammation.
Collapse
Affiliation(s)
- K-A Steen Burrell
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - J Layzer
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - B A Sullenger
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| |
Collapse
|
16
|
Woodruff RS, Ivanov I, Verhamme IM, Sun MF, Gailani D, Sullenger BA. Generation and characterization of aptamers targeting factor XIa. Thromb Res 2017. [PMID: 28644959 DOI: 10.1016/j.thromres.2017.06.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND The plasma protease factor XIa (FXIa) has become a target of interest for therapeutics designed to prevent or treat thrombotic disorders. METHODS We used a solution-based, directed evolution approach called systematic evolution of ligands by exponential enrichment (SELEX) to isolate RNA aptamers that target the FXIa catalytic domain. RESULTS Two aptamers, designated 11.16 and 12.7, were identified that bound to previously identified anion binding and serpin bindings sites on the FXIa catalytic domain. The aptamers were non-competitive inhibitors of FXIa cleavage of a tripeptide chromogenic substrate and of FXIa activation of factor IX. In normal human plasma, aptamer 12.7 significantly prolonged the aPTT clotting time. CONCLUSIONS The results show that novel inhibitors of FXIa can be prepared using SELEX techniques. RNA aptamers can bind to distinct sites on the FXIa catalytic domain and noncompetitively inhibit FXIa activity toward its primary macromolecular substrate factor IX with different levels of potency. Such compounds can be developed for use as therapeutic inhibitors.
Collapse
Affiliation(s)
- R S Woodruff
- Department of Surgery, Duke University Medical Center, Durham, NC, United States; University Program in Genetics and Genomics, Duke University, Durham, NC, United States
| | - I Ivanov
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - I M Verhamme
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - M-F Sun
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - D Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - B A Sullenger
- Department of Surgery, Duke University Medical Center, Durham, NC, United States.
| |
Collapse
|
17
|
Stoll H, Steinle H, Wilhelm N, Hann L, Kunnakattu SJ, Narita M, Schlensak C, Wendel HP, Avci-Adali M. Rapid Complexation of Aptamers by Their Specific Antidotes. Molecules 2017; 22:molecules22060954. [PMID: 28594360 PMCID: PMC6152687 DOI: 10.3390/molecules22060954] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/04/2017] [Accepted: 06/05/2017] [Indexed: 11/06/2022] Open
Abstract
Nucleic acid ligands, aptamers, harbor the unique characteristics of small molecules and antibodies. The specificity and high affinity of aptamers enable their binding to different targets, such as small molecules, proteins, or cells. Chemical modifications of aptamers allow increased bioavailability. A further great benefit of aptamers is the antidote (AD)-mediated controllability of their effect. In this study, the AD-mediated complexation and neutralization of the thrombin binding aptamer NU172 and Toll-like receptor 9 (TLR9) binding R10-60 aptamer were determined. Thereby, the required time for the generation of aptamer/AD-complexes was analyzed at 37 °C in human serum using gel electrophoresis. Afterwards, the blocking of aptamers’ effects was analyzed by determining the activated clotting time (ACT) in the case of the NU172 aptamer, or the expression of immune activation related genes IFN-1β, IL-6, CXCL-10, and IL-1β in the case of the R10-60 aptamer. Gel electrophoresis analyses demonstrated the rapid complexation of the NU172 and R10-60 aptamers by complementary AD binding after just 2 min of incubation in human serum. A rapid neutralization of anticoagulant activity of NU172 was also demonstrated in fresh human whole blood 5 min after addition of AD. Furthermore, the TLR9-mediated activation of PMDC05 cells was interrupted after the addition of the R10-60 AD. Using these two different aptamers, the rapid antagonizability of the aptamers was demonstrated in different environments; whole blood containing numerous proteins, cells, and different small molecules, serum, or cell culture media. Thus, nucleic acid ADs are promising molecules, which offer several possibilities for different in vivo applications, such as antagonizing aptamer-based drugs, immobilization, or delivery of oligonucleotides to defined locations.
Collapse
Affiliation(s)
- Heidi Stoll
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Heidrun Steinle
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Nadja Wilhelm
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Ludmilla Hann
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Silju-John Kunnakattu
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Miwako Narita
- Laboratory of Hematology and Oncology, Graduate School of Health Sciences, Niigata University, Niigata 951-8518, Japan.
| | - Christian Schlensak
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Hans P Wendel
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| | - Meltem Avci-Adali
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, 72076 Tuebingen, Germany.
| |
Collapse
|
18
|
Donkor DA, Bhakta V, Eltringham-Smith LJ, Stafford AR, Weitz JI, Sheffield WP. Selection and characterization of a DNA aptamer inhibiting coagulation factor XIa. Sci Rep 2017; 7:2102. [PMID: 28522812 PMCID: PMC5437010 DOI: 10.1038/s41598-017-02055-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 04/05/2017] [Indexed: 12/26/2022] Open
Abstract
Factor XIa (FXIa) is a serine protease that catalyzes the activation of Factor IX (FIX) in the blood coagulation cascade. FXIa and its precursor FXI are emergent therapeutic targets for the development of safer anticoagulant agents. Here, we sought a novel DNA-based agent to inhibit FXIa. Towards this goal, an 80 base, single-stranded DNA aptamer library (containing a 40 base randomized core) was screened for FXIa-binding candidates, using ten rounds of positive and negative selection. After selection, 6 of 89 different sequences inhibited FXIa-mediated chromogenic substrate S2366 cleavage. The most active anti-FXIa aptamer had a hypervariable central sequence 5′-AACCTATCGGACTATTGTTAGTGATTTTTATAGTGT-3′ and was designated Factor ELeven Inhibitory APtamer (FELIAP). FELIAP, but not a scrambled aptamer control (SCRAPT), competitively inhibited FXIa-catalyzed S2366 cleavage, FIX activation, and complex formation with antithrombin. No effect of FELIAP on FXI activation was observed. FELIAP inhibited plasma clotting and thrombin generation assays to a significantly greater extent than SCRAPT. Immobilized FELIAP bound FXIa with strong affinity and an equilibrium binding constant (KD) in the low nanomolar range determined using surface plasmon resonance. FELIAP is the first FXIa-inhibitory aptamer to be described and constitutes a lead compound to develop related aptamers for in vivo use.
Collapse
Affiliation(s)
- David A Donkor
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Varsha Bhakta
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada
| | | | - Alan R Stafford
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
| | - Jeffrey I Weitz
- Departments of Medicine and Biochemistry and Biomedical Sciences, McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
| | - William P Sheffield
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario, Canada. .,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
19
|
Zümrüt HE, Batool S, Van N, George S, Bhandari S, Mallikaratchy P. Structural optimization of an aptamer generated from Ligand-Guided Selection (LIGS) resulted in high affinity variant toward mIgM expressed on Burkitt's lymphoma cell lines. Biochim Biophys Acta Gen Subj 2017; 1861:1825-1832. [PMID: 28363693 DOI: 10.1016/j.bbagen.2017.03.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 11/27/2022]
Abstract
Aptamers are synthetic, short nucleic acid molecules capable of specific target recognition. Aptamers are selected using a screening method termed Systematic Evolution of Ligands by Exponential enrichment (SELEX). We recently have introduced a variant of SELEX called "Ligand-Guided-Selection" (LIGS) that allows the identification of specific aptamers against known cell-surface proteins. Utilizing LIGS, we introduced three specific aptamers against membrane-bound IgM (mIgM), which is the hallmark of B cells. Out of the three aptamers selected against mIgM, an aptamer termed R1, in particular, was found to be interesting due to its ability to recognize mIgM on target cells and then block anti-IgM antibodies binding their antigen. We systematically truncated parent aptamer R1 to design shorter variants with enhanced affinity. Importantly, herein we show that the specificity of the most optimized variant of R1 aptamer is similar to that of anti-IgM antibody, indicating that the specificity of the ligand utilized in selective elution of the aptamer determines the specificity of the LIGS-generated aptamer. Furthermore, we report that truncated variants of R1 are able to recognize mIgM-positive human B lymphoma BJAB cells at physiological temperature, demonstrating that LIGS-generated aptamers could be re-optimized into higher affinity variants. Collectively, these findings show the significance of LIGS in generating highly specific aptamers with potential applications in biomedicine.
Collapse
Affiliation(s)
- Hasan E Zümrüt
- Ph.D. Program in Chemistry and Biochemistry, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA
| | - Sana Batool
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, NY 10468, USA
| | - Nabeela Van
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, NY 10468, USA
| | - Shanell George
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, NY 10468, USA
| | - Sanam Bhandari
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, NY 10468, USA
| | - Prabodhika Mallikaratchy
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, NY 10468, USA; Ph.D. Program in Chemistry and Biochemistry, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA; Ph.D. Program in Molecular, Cellular and Developmental Biology, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA.
| |
Collapse
|
20
|
Jin NZ, Gopinath SC. Potential blood clotting factors and anticoagulants. Biomed Pharmacother 2016; 84:356-365. [DOI: 10.1016/j.biopha.2016.09.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/06/2016] [Accepted: 09/15/2016] [Indexed: 12/20/2022] Open
|
21
|
Prediction of aptamer-protein interacting pairs using an ensemble classifier in combination with various protein sequence attributes. BMC Bioinformatics 2016; 17:225. [PMID: 27245069 PMCID: PMC4888498 DOI: 10.1186/s12859-016-1087-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/17/2016] [Indexed: 02/05/2023] Open
Abstract
Background Aptamer-protein interacting pairs play a variety of physiological functions and therapeutic potentials in organisms. Rapidly and effectively predicting aptamer-protein interacting pairs is significant to design aptamers binding to certain interested proteins, which will give insight into understanding mechanisms of aptamer-protein interacting pairs and developing aptamer-based therapies. Results In this study, an ensemble method is presented to predict aptamer-protein interacting pairs with hybrid features. The features for aptamers are extracted from Pseudo K-tuple Nucleotide Composition (PseKNC) while the features for proteins incorporate Discrete Cosine Transformation (DCT), disorder information, and bi-gram Position Specific Scoring Matrix (PSSM). We investigate predictive capabilities of various feature spaces. The proposed ensemble method obtains the best performance with Youden’s Index of 0.380, using the hybrid feature space of PseKNC, DCT, bi-gram PSSM, and disorder information by 10-fold cross validation. The Relief-Incremental Feature Selection (IFS) method is adopted to obtain the optimal feature set. Based on the optimal feature set, the proposed method achieves a balanced performance with a sensitivity of 0.753 and a specificity of 0.725 on the training dataset, which indicates that this method can solve the imbalanced data problem effectively. To evaluate the prediction performance objectively, an independent testing dataset is used to evaluate the proposed method. Encouragingly, our proposed method performs better than previous study with a sensitivity of 0.738 and a Youden’s Index of 0.451. Conclusions These results suggest that the proposed method can be a potential candidate for aptamer-protein interacting pair prediction, which may contribute to finding novel aptamer-protein interacting pairs and understanding the relationship between aptamers and proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12859-016-1087-5) contains supplementary material, which is available to authorized users.
Collapse
|
22
|
Rice NT, Szlam F, Varner JD, Bernstein PS, Szlam AD, Tanaka KA. Differential Contributions of Intrinsic and Extrinsic Pathways to Thrombin Generation in Adult, Maternal and Cord Plasma Samples. PLoS One 2016; 11:e0154127. [PMID: 27196067 PMCID: PMC4873248 DOI: 10.1371/journal.pone.0154127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 04/09/2016] [Indexed: 11/18/2022] Open
Abstract
Background Thrombin generation (TG) is a pivotal process in achieving hemostasis. Coagulation profiles during pregnancy and early neonatal period are different from that of normal (non-pregnant) adults. In this ex vivo study, the differences in TG in maternal and cord plasma relative to normal adult plasma were studied. Methods Twenty consented pregnant women and ten consented healthy adults were included in the study. Maternal and cord blood samples were collected at the time of delivery. Platelet-poor plasma was isolated for the measurement of TG. In some samples, anti-FIXa aptamer, RB006, or a TFPI inhibitor, BAX499 were added to elucidate the contribution of intrinsic and extrinsic pathway to TG. Additionally, procoagulant and inhibitor levels were measured in maternal and cord plasma, and these values were used to mathematically simulate TG. Results Peak TG was increased in maternal plasma (393.6±57.9 nM) compared to adult and cord samples (323.2±38.9 nM and 209.9±29.5 nM, respectively). Inhibitory effects of RB006 on TG were less robust in maternal or cord plasma (52% vs. 12% respectively) than in adult plasma (81%). Likewise the effectiveness of BAX499 as represented by the increase in peak TG was much greater in adult (21%) than in maternal (10%) or cord plasma (12%). Further, BAX499 was more effective in reversing RB006 in adult plasma than in maternal or cord plasma. Ex vivo data were reproducible with the results of the mathematical simulation of TG. Conclusion Normal parturient plasma shows a large intrinsic pathway reserve for TG compared to adult and cord plasma, while TG in cord plasma is sustained by extrinsic pathway, and low levels of TFPI and AT.
Collapse
Affiliation(s)
- Nicklaus T. Rice
- Department of Obstetric and Gynecology, Vanderbilt Medical Center, Nashville, Tennessee, United States of America
| | - Fania Szlam
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Jeffrey D. Varner
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana, United States of America
| | - Peter S. Bernstein
- Department of Clinical Obstetric & Gynecology and Women’s Health, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York, United States of America
| | - Arthur D. Szlam
- Department of Mathematics, CCNY, New York, United States of America
| | - Kenichi A. Tanaka
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
23
|
Soule EE, Bompiani KM, Woodruff RS, Sullenger BA. Targeting Two Coagulation Cascade Proteases with a Bivalent Aptamer Yields a Potent and Antidote-Controllable Anticoagulant. Nucleic Acid Ther 2015; 26:1-9. [PMID: 26584417 DOI: 10.1089/nat.2015.0565] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Potent and rapid-onset anticoagulation is required for several clinical settings, including cardiopulmonary bypass surgery. In addition, because anticoagulation is associated with increased bleeding following surgery, the ability to rapidly reverse such robust anticoagulation is also important. Previously, we observed that no single aptamer was as potent as heparin for anticoagulating blood. However, we discovered that combinations of two aptamers were as potent as heparin. Herein, we sought to combine two individual anticoagulant aptamers into a single bivalent RNA molecule in an effort to generate a single molecule that retained the potent anticoagulant activity of the combination of individual aptamers. We created four bivalent aptamers that can inhibit Factor X/Xa and prothrombin/thrombin and anticoagulate plasma, as well as the combination of individual aptamers. Detailed characterization of the shortest bivalent aptamer indicates that each aptamer retains full binding and functional activity when presented in the bivalent context. Finally, reversal of this bivalent aptamer with a single antidote was explored, and anticoagulant activity could be rapidly turned off in a dose-dependent manner. These studies demonstrate that bivalent anticoagulant aptamers represent a novel and potent approach to actively and reversibly control coagulation.
Collapse
Affiliation(s)
- Erin E Soule
- Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center , Durham, North Carolina
| | - Kristin M Bompiani
- Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center , Durham, North Carolina
| | - Rebecca S Woodruff
- Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center , Durham, North Carolina
| | - Bruce A Sullenger
- Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center , Durham, North Carolina
| |
Collapse
|
24
|
Woodruff RS, Sullenger BA. Modulation of the Coagulation Cascade Using Aptamers. Arterioscler Thromb Vasc Biol 2015; 35:2083-91. [PMID: 26315404 PMCID: PMC5304947 DOI: 10.1161/atvbaha.115.300131] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/19/2015] [Indexed: 11/16/2022]
Abstract
As a novel class of therapeutics, aptamers, or nucleic acid ligands, have garnered clinical interest because of the ease of isolating a highly specific aptamer against a wide range of targets, their chemical flexibility and synthesis, and their inherent ability to have their function reversed. The following review details the development and molecular mechanisms of aptamers targeting specific proteases in the coagulation cascade. The ability of these anticoagulant aptamers to bind to and inhibit exosite function rather than binding within the active site highlights the importance of exosites in blocking protein function. As both exosite inhibitors and reversible agents, the use of aptamers is a promising strategy for future therapeutics.
Collapse
Affiliation(s)
- Rebecca S Woodruff
- From the Bloodworks Northwest Research Institute, Seattle, WA (R.S.W.); Department of Medicine, University of Washington, Seattle (R.S.W.); and Duke Translational Research Institute, Department of Surgery, Duke University Medical Center, Durham, NC (B.A.S.)
| | - Bruce A Sullenger
- From the Bloodworks Northwest Research Institute, Seattle, WA (R.S.W.); Department of Medicine, University of Washington, Seattle (R.S.W.); and Duke Translational Research Institute, Department of Surgery, Duke University Medical Center, Durham, NC (B.A.S.).
| |
Collapse
|
25
|
Abstract
Coagulation and anticoagulation system is kept in balance by the orchestrated action of a variety of biological factors, and the disruption of this balance leads to the risk of hemorrhage or thrombosis. Oligonucleotide aptamers are single-stranded DNA (ssDNA) or RNA ligands that are synthesized in vitro and bind to target molecules through dimensional structure with high specificity and affinity, and thus represent attractive candidates for the development of agents to maintain the balance of coagulation and anticoagulation. In this review, we summarize recent progress in aptamer-based application in the modulation of coagulation. The aptamers with specific chemical and biological characteristics have great potential to be explored as agents for the treatment of blood coagulation abnormalities.
Collapse
|
26
|
Probing the coagulation pathway with aptamers identifies combinations that synergistically inhibit blood clot formation. ACTA ACUST UNITED AC 2014; 21:935-44. [PMID: 25065530 DOI: 10.1016/j.chembiol.2014.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/03/2014] [Accepted: 05/30/2014] [Indexed: 11/21/2022]
Abstract
Coordinated enzymatic reactions regulate blood clot generation. To explore the contributions of various coagulation enzymes in this process, we utilized a panel of aptamers against factors VIIa, IXa, Xa, and prothrombin. Each aptamer dose-dependently inhibited clot formation, yet none was able to completely impede this process in highly procoagulant settings. However, several combinations of two aptamers synergistically impaired clot formation. One extremely potent aptamer combination was able to maintain human blood fluidity even during extracorporeal circulation, a highly procoagulant setting encountered during cardiopulmonary bypass surgery. Moreover, this aptamer cocktail could be rapidly reversed with antidotes to restore normal hemostasis, indicating that even highly potent aptamer combinations can be rapidly controlled. These studies highlight the potential utility of using sets of aptamers to probe the functions of proteins in molecular pathways for research and therapeutic ends.
Collapse
|