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Misenheimer TM, Lasarev MR, Kumfer KT, Sheehan JP, Schwartz BS. A novel factor IXa-specific enzyme-linked immunosorbent assay detects factor IXa in human plasma. Res Pract Thromb Haemost 2024; 8:102338. [PMID: 38433974 PMCID: PMC10907220 DOI: 10.1016/j.rpth.2024.102338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/21/2023] [Accepted: 01/18/2024] [Indexed: 03/05/2024] Open
Abstract
Background Factor (F)IXa activity has been detected in human plasma and may impact thrombotic risk. Current FIXa activity assays are complex and cumbersome. Objectives To develop a reproducible enzyme-linked immunosorbent assay (ELISA) using a novel monoclonal antibody that detects total FIXa in human plasma. Methods A monoclonal antibody was raised against the new N-terminus exposed upon activation of FIX to FIXa by cleavage after R226. This antibody is specific for FIXa protease and does not recognize FIX zymogen or FIXα. The antibody was used to develop a FIXa-specific ELISA capable of quantifying total FIXa (free FIXa and FIXa-antithrombin complex) in human plasma. Total FIXa quantified using the ELISA was compared to that of FIXa-antithrombin quantified using modifications of a previously described ELISA. Results The FIXa-specific ELISA was reproducible and quantified total FIXa in human plasma. Total FIXa levels correlated with FIXa-antithrombin levels. Conclusion A monoclonal antibody was developed that specifically detects human FIXa protease. A FIXa-specific ELISA using the new antibody is capable of reproducibly measuring total FIXa in human plasma (both free FIXa and FIXa-antithrombin). This assay should facilitate the evaluation of total FIXa levels in a variety of clinical circumstances.
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Affiliation(s)
| | - Michael R. Lasarev
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kraig T. Kumfer
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - John P. Sheehan
- Department of Medicine/Hematology-Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
- University of Wisconsin-Madison Carbone Cancer Center, Madison, Wisconsin, USA
| | - Bradford S. Schwartz
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Departments of Medicine/Hematology-Oncology, and Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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2
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Ivanciu L, Arruda VR, Camire RM. Factor IXa variants resistant to plasma inhibitors enhance clot formation in vivo. Blood 2023; 141:2022-2032. [PMID: 36724452 PMCID: PMC10163311 DOI: 10.1182/blood.2022018083] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 12/28/2022] [Accepted: 01/13/2023] [Indexed: 02/03/2023] Open
Abstract
Factor IXa (FIXa) plays a pivotal role in coagulation by contributing to FX activation via the intrinsic pathway. Although antithrombin (AT) and other plasma inhibitors are thought to regulate FIXa procoagulant function, the impact of FIXa inhibition on thrombin generation and clot formation in vivo remains unclear. Here, we generated FIXa variants with altered reactivity to plasma inhibitors that target the FIXa active site but maintain procoagulant function when bound to its cofactor, FVIIIa. We found that selected FIXa variants (eg, FIXa-V16L) have a prolonged activity half-life in the plasma due, in part, to AT resistance. Studies using hemophilia B mice have shown that delayed FIXa inhibition has a major impact on reducing the bleeding phenotype and promoting thrombus formation following administration of FIX protein. Overall, these results demonstrate that the regulation of FIXa inhibition contributes in a major way to the spatial and temporal control of coagulation at the site of vascular injury. Our findings provide novel insights into the physiological regulation of FIXa, enhance our understanding of thrombus formation in vivo via the intrinsic pathway, and suggest that altering FIXa inhibition could have therapeutic benefits.
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Affiliation(s)
- Lacramioara Ivanciu
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Valder R. Arruda
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Rodney M. Camire
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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3
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Abdelfadiel E, Gunta R, Villuri BK, Afosah DK, Sankaranarayanan NV, Desai UR. Designing Smaller, Synthetic, Functional Mimetics of Sulfated Glycosaminoglycans as Allosteric Modulators of Coagulation Factors. J Med Chem 2023; 66:4503-4531. [PMID: 37001055 PMCID: PMC10108365 DOI: 10.1021/acs.jmedchem.3c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Indexed: 04/03/2023]
Abstract
Natural glycosaminoglycans (GAGs) are arguably the most diverse collection of natural products. Unfortunately, this bounty of structures remains untapped. Decades of research has realized only one GAG-like synthetic, small-molecule drug, fondaparinux. This represents an abysmal output because GAGs present a frontier that few medicinal chemists, and even fewer pharmaceutical companies, dare to undertake. GAGs are heterogeneous, polymeric, polydisperse, highly water soluble, synthetically challenging, too rapidly cleared, and difficult to analyze. Additionally, GAG binding to proteins is not very selective and GAG-binding sites are shallow. This Perspective attempts to transform this negative view into a much more promising one by highlighting recent advances in GAG mimetics. The Perspective focuses on the principles used in the design/discovery of drug-like, synthetic, sulfated small molecules as allosteric modulators of coagulation factors, such as antithrombin, thrombin, and factor XIa. These principles will also aid the design/discovery of sulfated agents against cancer, inflammation, and microbial infection.
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Affiliation(s)
- Elsamani
I. Abdelfadiel
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
| | - Rama Gunta
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Bharath Kumar Villuri
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Daniel K. Afosah
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Nehru Viji Sankaranarayanan
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Umesh R. Desai
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
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4
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Li M, Jiang S, Liu S, Jin Y, Wang M. Analysis of phenotype and gene mutation in three pedigrees with inherited antithrombin deficiency. J Clin Lab Anal 2022; 36:e24732. [PMID: 36268972 DOI: 10.1002/jcla.24732] [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: 10/10/2021] [Revised: 09/05/2022] [Accepted: 09/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inherited AT deficiency is an autosomal-dominant thrombophilic disorder usually caused by various SERPINC1 defects associated with a high risk of recurrent venous thromboembolism. In this article, the phenotype, gene mutation, and molecular pathogenic mechanisms were determined in three pedigrees with inherited AT deficiency. METHODS Coagulation indices were examined on STAGO STA-R-MAX analyzer. The AT:Ag was analyzed by ELISA. All exons and flanking sequences of SERPINC1 were amplified by PCR. AT wild type and three mutant expression plasmids were constructed and then transfected into HEK293FT cells. The expression level of AT protein was analyzed by ELISA and Western blot. RESULTS The AT:A and AT:Ag of probands 1 and 3 were decreased to 49% and 52 mg/dL, 38% and 44 mg/dL, respectively. The AT:A of proband 2 was decreased to 32%. The SERPINC1 gene analysis indicated that there was a p.Ile421Thr in proband 1, a p.Leu417Gln in proband 2, and a p.Met252Thr in proband 3, respectively. The AT mRNA expression level of the three mutants was not significantly different from AT-WT by qRT-PCR. The results of ELISA and Western blot tests showed that the AT-M252T and AT-I421T mutants had a higher AT expression than the AT wild type (AT-WT), and the AT protein expression of AT-L417Q mutants had no significant difference compared with AT-WT in the cell lysate. The AT expression levels of AT-M252T and AT-I421T mutants were lower than that of AT-WT, and there was no significant difference between AT-L417Q mutant and AT-WT in the supernatant. CONCLUSION The p.I421T and p.M252T mutations affected the secretion of AT protein leading to type I AT deficiency of probands 1 and 3. The p.Leu417Gln mutation was responsible for the impaired or ineffective activity AT protein in proband 2 and caused type II AT deficiency.
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Affiliation(s)
- Min Li
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Shuting Jiang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Siqi Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yanhui Jin
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Mingshan Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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Antithrombin protects against Plasmodium falciparum histidine-rich protein II-mediated inflammation and coagulation. Blood Adv 2021; 6:931-945. [PMID: 34768285 PMCID: PMC8945290 DOI: 10.1182/bloodadvances.2021005836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/01/2021] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum (Pf)-derived histidine-rich protein II (HRPII) has been shown to inhibit heparin-dependent anticoagulant activity of antithrombin (AT) and induce inflammation in vitro and in vivo. In a recent study, we showed that HRPII interacts with the AT-binding vascular glycosaminoglycans (GAGs) to not only disrupt the barrier-permeability function of endothelial cells but also inhibit the anti-inflammatory signaling function of AT. Here we investigated the mechanisms of the pro-inflammatory function of HRPII and the protective activity of AT in cellular and animal models. We found that AT competitively inhibits the GAG-dependent HRPII-mediated activation of NF-κB and expression of intercellular cell adhesion molecule 1 (ICAM1) in endothelial cells. Furthermore, AT inhibits HRPII-mediated histone H3 citrullination and neutrophil extracellular trap (NET) formation in HL60 cells and freshly isolated human neutrophils. In vivo, HRPII induced Mac1 expression on blood neutrophils, MPO release in plasma, neutrophil infiltration and histone H3 citrullination in the lung tissues. HRPII also induced endothelial cell activation as measured by increased ICAM1 expression and elevated vascular permeability in the lungs. AT effectively inhibited HRPII-mediated neutrophil infiltration, NET formation and endothelial cell activation in vivo. AT also inhibited HRPII-meditated deposition of platelets and fibrin(ogen) in the lungs and circulating level of von Willebrand factor in the plasma. We conclude that AT exerts protective effects against pathogenic effects of Pf-derived HRPII in both cellular and animal models.
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Biswas I, Panicker SR, Cai XS, Giri H, Rezaie AR. Extracellular Histones Bind Vascular Glycosaminoglycans and Inhibit the Anti-Inflammatory Function of Antithrombin. Cell Physiol Biochem 2021; 55:605-617. [PMID: 34655467 DOI: 10.33594/000000438] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND/AIMS Binding of histones to molecular pattern recognition receptors on endothelial cells and leukocytes provokes proinflammatory responses and promotes activation of coagulation. Histones also bind therapeutic heparins, thereby neutralizing their anticoagulant functions. The aim of this study was to test the hypothesis that histones can interact with the antithrombin (AT)-binding vascular glycosaminoglycans (GAGs) to induce inflammation and inhibit the anti-inflammatory function of AT. METHODS We evaluated the heparin-binding function of histones by an AT-dependent protease-inhibition assay. Furthermore, we treated endothelial cells with histones in the absence and presence of AT and monitored cellular phenotypes employing established signaling assays. RESULTS Histones neutralized AT-dependent anticoagulant function of heparin in both purified protease-inhibition and plasma-based assays. Histones also disrupted endothelial cell barrier-permeability function by a GAG-dependent mechanism as evidenced by the GAG-antagonist, surfen, abrogating their disruptive effects. Further studies revealed histones and AT compete for overlapping binding-sites on GAGs, thus increasing concentrations of one protein abrogated effects of the other. Histones elicited proapoptotic effects by inducing nuclear localization of PKC-δ in endothelial cells and barrier-disruptive effects by destabilizing VE-cadherin, which were inhibited by AT, but not by a D-helix mutant of AT incapable of interacting with GAGs. Finally, histones induced release of Weibel-Palade body contents, VWF and angiopoietin-2, and promoted expression of cell adhesion molecules on endothelial cells, which were all downregulated by AT but not by D-helix mutant of AT. CONCLUSION We conclude that histones and AT compete for overlapping binding sites on vascular GAGs to modulate coagulation and inflammation.
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Affiliation(s)
- Indranil Biswas
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Sumith R Panicker
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Xiaofeng S Cai
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Hemant Giri
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Alireza R Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA, .,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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7
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Qiu M, Huang S, Luo C, Wu Z, Liang B, Huang H, Ci Z, Zhang D, Han L, Lin J. Pharmacological and clinical application of heparin progress: An essential drug for modern medicine. Biomed Pharmacother 2021; 139:111561. [PMID: 33848775 DOI: 10.1016/j.biopha.2021.111561] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/20/2021] [Accepted: 03/31/2021] [Indexed: 12/22/2022] Open
Abstract
Heparin is the earliest and most widely used anticoagulant and antithrombotic drug that is still used in a variety of clinical indications. Since it was discovered in 1916, after more than a century of repeated exploration, heparin has not been replaced by other drugs, but a great progress has been made in its basic research and clinical application. Besides anticoagulant and antithrombotic effects, heparin also has antitumor, anti-inflammatory, antiviral, and other pharmacological activities. It is widely used clinically in cardiovascular and cerebrovascular diseases, lung diseases, kidney diseases, cancer, etc., as the first anticoagulant medicine in COVID-19 exerts anticoagulant, anti-inflammatory and antiviral effects. At the same time, however, it also leads to a lot of adverse reactions, such as bleeding, thrombocytopenia, elevated transaminase, allergic reactions, and others. This article comprehensively reviews the modern research progress of heparin compounds; discusses the structure, preparation, and adverse reactions of heparin; emphasizes the pharmacological activity and clinical application of heparin; reveals the possible mechanism of the therapeutic effect of heparin in related clinical applications; provides evidence support for the clinical application of heparin; and hints on the significance of exploring the wider application fields of heparin.
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Affiliation(s)
- Min Qiu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Shengjie Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Chuanhong Luo
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Zhenfeng Wu
- Key Laboratory of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, PR China
| | - Binzhu Liang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Haozhou Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Zhimin Ci
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Dingkun Zhang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Li Han
- State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China.
| | - Junzhi Lin
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610072, PR China.
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Type II antithrombin deficiency caused by a novel missense mutation (p.Leu417Gln) in a Chinese family. Blood Coagul Fibrinolysis 2021; 32:57-63. [PMID: 33196512 DOI: 10.1097/mbc.0000000000000973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
THE AIM OF THE REPORT WAS T o explore the phenotype and genotype of a hereditary antithrombin deficient Chinese family. Functional and molecular analysis of the proband and his family members was performed. Online bioinformatics software was used to predict the pathogenicity of the novel mutation. ClustalX-2.1-win and PyMol software were applied to conservative analysis and generate molecular graphic images, respectively. Functional analysis had shown that the antithrombin (AT):A of the proband was reduced to 32% whereas AT:Ag was normal. Molecular analysis revealed a heterozygous missense mutation p. Leu417Gln in exon 7 of SERPINC1 gene. Bioinformatics and model analysis indicated that this mutation could affect the integrity of local intermolecular structures, resulting in a mild type of antithrombin deficiency but when combined with other genetic or acquired thrombophilic factors, patients may develop venous thrombosis. The p.Leu417Gln mutation was responsible for the decrease of AT:A in this family and caused type II antithrombin deficiency.
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9
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Molecular basis of SERPINC1 mutations in Japanese patients with antithrombin deficiency. Thromb Res 2019; 178:159-170. [PMID: 31030036 DOI: 10.1016/j.thromres.2019.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/20/2019] [Accepted: 04/05/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Congenital antithrombin (AT) deficiency, which arises from various SERPINC1 defects, is an autosomal-dominant thrombophilic disorder associated with a high risk of recurrent venous thromboembolism. PATIENTS/METHODS We investigated SERPINC1 defects in Japanese patients with congenital AT deficiency who developed venous thromboembolism or had a family history of deep vein thrombosis. We analyzed the full DNA sequences of SERPINC1 exons and exon-intron junctions by PCR-mediated direct sequencing. If no mutation was found, multiplex ligation-dependent probe amplification (MLPA) was conducted for the relative quantification of the copy number of all exons in SERPINC1. If splice-site mutations were detected, mRNA splicing abnormalities were further investigated using an in vitro cell-based exontrap assay. RESULTS We identified 19 different SERPINC1 abnormalities, including 8 novel mutations, in 21 Japanese patients with AT deficiency. These abnormalities were distributed as follows: 9 missense mutations (42.9%), 3 nonsense mutations (14.3%), 1 splice-site mutation (4.8%), 2 small insertions (9.5%), 2 deletion mutations (9.5%) and 4 large deletions (19.0%). Cases with large deletions of SERPINC1 included Alu-mediated gene rearrangements and non-Alu-mediated complex gene rearrangements; the latter could conceivably be explained using the fork stalling and template switching (FoSTeS) model. CONCLUSIONS We identified a variety of SERPINC1 defects in Japanese patients with AT deficiency. The SERPINC1 mutations detected in patients with type I AT deficiency included single nucleotide missense or nonsense mutations, small intragenic insertions or deletions, and large genomic structural deletions. Large deletions of SERPINC1 were caused by various recurrent or non-recurrent complex genomic rearrangement mutations.
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10
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Li YQ, Guo T, Wang QY, Liu H, Wu YY, Cheng ZP, Hu B, Lu X, Yu JM, Deng J, Wang HF, Sun CY, Yang Y, Zeng W, Tang L, Jian XR, Hu Y. Genetic analysis should be included in clinical practice when screening for antithrombin deficiency. Thromb Haemost 2017; 113:262-71. [DOI: 10.1160/th14-05-0446] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/30/2014] [Indexed: 12/12/2022]
Abstract
SummaryAntithrombin (AT) deficiency increases the risk of thrombosis. Current evidence shows that some SERPINC1 mutations responsible for antithrombin deficiency often present a slightly decreased or normal activity and therefore could not be detected by functional tests. This study was designed to compare activity assays and direct genetic analyses in identifying hereditary antithrombin deficiency. In total, 400 consecutive patients with venous thrombosis were enrolled. Functional assays showed that 16 of the 400 individuals had decreased antithrombin activity, and 14 of them were confirmed by genetic analysis. Of the remaining 384 patients, 95 individuals without a known risk factor and 95 individuals with predisposing factors were also selected for gene sequencing. Eight additional causative mutations were identified in nine individuals and they should also be considered as antithrombin deficiency. In addition, a recurrent mutation, p.Arg356_Phe361del, was characterised. The mutant appeared to have a partially impaired secretion and a reduction in functional activity by 50 %. This study indicated that including genetic analysis in screening tests for identifying antithrombin deficiency was essential. Specifically, a genetic analysis of SERPINC1 is strongly recommended when individuals experience unprovoked thrombotic diseases, even if the AT activities are normal.
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11
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Ma Y, Wang J, Gao J, Yang H, Wang Y, Manithody C, Li J, Rezaie AR. Antithrombin up-regulates AMP-activated protein kinase signalling during myocardial ischaemia/reperfusion injury. Thromb Haemost 2015; 113:338-49. [PMID: 25230600 PMCID: PMC4308562 DOI: 10.1160/th14-04-0360] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/09/2014] [Indexed: 11/05/2022]
Abstract
Antithrombin (AT) is a protein of the serpin superfamily involved in regulation of the proteolytic activity of the serine proteases of the coagulation system. AT is known to exhibit anti-inflammatory and cardioprotective properties when it binds to heparan sulfate proteoglycans (HSPGs) on vascular cells. AMP-activated protein kinase (AMPK) plays an important cardioprotective role during myocardial ischaemia and reperfusion (I/R). To determine whether the cardioprotective signaling function of AT is mediated through the AMPK pathway, we evaluated the cardioprotective activities of wild-type AT and its two derivatives, one having high affinity and the other no affinity for heparin, in an acute I/R injury model in C57BL/6J mice in which the left anterior descending coronary artery was occluded. The serpin derivatives were given 5 minutes before reperfusion. The results showed that AT-WT can activate AMPK in both in vivo and ex vivo conditions. Blocking AMPK activity abolished the cardioprotective function of AT against I/R injury. The AT derivative having high affinity for heparin was more effective in activating AMPK and in limiting infraction, but the derivative lacking affinity for heparin was inactive in eliciting AMPK-dependent cardioprotective activity. Activation of AMPK by AT inhibited the inflammatory c-Jun N-terminal protein kinase (JNK) pathway during I/R. Further studies revealed that the AMPK activity induced by AT also modulates cardiac substrate metabolism by increasing glucose oxidation but inhibiting fatty acid oxidation during I/R. These results suggest that AT binds to HSPGs on heart tissues to invoke a cardioprotective function by triggering cardiac AMPK activation, thereby attenuating JNK inflammatory signalling pathways and modulating substrate metabolism during I/R.
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Affiliation(s)
| | | | | | | | | | | | - Ji Li
- Ji Li, PhD, Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY 14214, USA, Tel.: +1 716 829 5711, Fax: +1 716 829 2801, E-mail:
| | - Alireza R Rezaie
- Alireza R. Rezaie, PhD, Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA, Tel.: +1 314 977 9240, Fax: +1 314 977 9205, E-mail:
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12
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Yang L, Dinarvand P, Qureshi SH, Rezaie AR. Engineering D-helix of antithrombin in alpha-1-proteinase inhibitor confers antiinflammatory properties on the chimeric serpin. Thromb Haemost 2014; 112:164-75. [PMID: 24522239 PMCID: PMC4087087 DOI: 10.1160/th13-12-1029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 01/29/2014] [Indexed: 01/20/2023]
Abstract
Antithrombin (AT) is a heparin-binding serpin in plasma which regulates the proteolytic activity of procoagulant proteases of the clotting cascade. In addition to being an anticoagulant, AT also exhibits antiinflammatory activities when it binds to cell surface heparan sulfate proteoglycans (HSPGs) on the endothelium via its basic residues of D-helix to elicit intracellular signalling responses. By contrast to AT, α1-proteinase inhibitor (α1-PI) is a non-heparin-binding serpin that exhibits very slow reactivity with coagulation proteases and possesses no HSPG-dependent antiinflammatory properties. To determine whether the antiinflammatory signaling specificity of AT can be transferred to α1-PI, we replaced the D-helix of human α1-PI with the corresponding sequence of human AT and expressed the chimeric serpin α1-PI/D-helix) in a bacterial expression system. High molecular weight heparin bound to α1-PI/D-helix and accelerated the inhibition of thrombin by the serpin mutant by a template mechanism reminiscent of the cofactor effect of heparin on inhibition of thrombin by AT. Like AT, α1-PI/D-helix exhibited antiinflammatory properties in both cellular and animal models. Thus, α1-PI/D-helix inhibited the barrier-disruptive effect of proinflammatory cytokines and inhibited the activation of nuclear factor-κB transcription factor in lipopolysaccharide-stimulated endothelial cells by a concentration-dependent manner. Furthermore, the chimeric serpin reduced lipopolysaccharide-mediated lethality, elicited a vascular protective effect and inhibited infiltration of activated leukocytes to the peritoneal cavity of mice in an HMGB1-mediated inflammatory model. These results suggest that grafting the D-helix of AT to α1-PI confers antiinflammatory properties on the serpin and that the chimeric serpin may have therapeutic utility for treating inflammatory disorders.
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Affiliation(s)
| | | | | | - A R Rezaie
- Alireza R. Rezaie, PhD, Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, 1100 S. Grand Blvd., St. Louis, MO 63104, USA, Tel.: +1 314 977 9240, Fax: +1 314 977 9205 , E-mail:
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13
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Zhang W, Sun YL, Chen DH. Effects of chitin and sepia ink hybrid hemostatic sponge on the blood parameters of mice. Mar Drugs 2014; 12:2269-81. [PMID: 24727395 PMCID: PMC4012435 DOI: 10.3390/md12042269] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 03/18/2014] [Accepted: 03/25/2014] [Indexed: 11/23/2022] Open
Abstract
Chitin and sepia ink hybrid hemostatic sponge (CTSH sponge), a new biomedical material, was extensively studied for its beneficial biological properties of hemostasis and stimulation of healing. However, studies examining the safety of CTSH sponge in the blood system are lacking. This experiment aimed to examine whether CTSH sponge has negative effect on blood systems of mice, which were treated with a dosage of CTSH sponge (135 mg/kg) through a laparotomy. CTSH sponge was implanted into the abdominal subcutaneous and a laparotomy was used for blood sampling from abdominal aortic. Several kinds of blood parameters were detected at different time points, which were reflected by coagulation parameters including thrombin time (TT), prothrombin time (PT), activated partial thromboplatin time (APTT), fibrinogen (FIB) and platelet factor 4 (PF4); anticoagulation parameter including antithrombin III (AT-III); fibrinolytic parameters including plasminogen (PLG), fibrin degradation product (FDP) and D-dimer; hemorheology parameters including blood viscosity (BV) and plasma viscosity (PV). Results showed that CTSH sponge has no significant effect on the blood parameters of mice. The data suggested that CTSH sponge can be applied in the field of biomedical materials and has potential possibility to be developed into clinical drugs of hemostatic agents.
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Affiliation(s)
- Wei Zhang
- Zhanjiang Normal University, Round Beibu Gulf Institute for the Protection and Utilization of Marine Animals in Medicine, Zhanjiang 524048, China.
| | - Yu-Lin Sun
- Zhanjiang Normal University, Round Beibu Gulf Institute for the Protection and Utilization of Marine Animals in Medicine, Zhanjiang 524048, China.
| | - Dao-Hai Chen
- Zhanjiang Normal University, Round Beibu Gulf Institute for the Protection and Utilization of Marine Animals in Medicine, Zhanjiang 524048, China.
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Maruyama K, Morishita E, Karato M, Kadono T, Sekiya A, Goto Y, Sato T, Nomoto H, Omi W, Tsuzura S, Imai H, Asakura H, Ohtake S, Nakao S. Antithrombin deficiency in three Japanese families: one novel and two reported point mutations in the antithrombin gene. Thromb Res 2013; 132:e118-23. [PMID: 23809926 DOI: 10.1016/j.thromres.2013.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/25/2013] [Accepted: 06/02/2013] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Inherited antithrombin (AT) deficiency is associated with a predisposition to familial venous thromboembolic disease. We analyzed the AT gene in three unrelated patients with an AT deficiency who developed thrombosis. MATERIALS AND METHODS We analyzed the SERPINC1 gene in three patients. Additionally, we expressed the three mutants in the COS-1 cells and compared their secretion rates and levels of AT activity with those of the wild-type (WT). RESULTS We identified three distinct heterozygous mutations of c.2534C>T: p.56Arginine → Cysteine (R56C), c.13398C>A: p.459Alanine → Aspartic acid (A459D) and c.2703C>G: p.112 Proline → Arginine (P112R). In the in vitro expression experiments, the AT antigen levels in the conditioned media (CM) of the R56C mutant were nearly equal to those of WT. In contrast, the AT antigen levels in the CM of the A459D and P112R mutants were significantly decreased. The AT activity of R56C was decreased in association with a shorter incubation time in a FXa inhibition assay and a thrombin inhibition-based activity test. However, the AT activity of R56C was comparable to that of WT when the incubation time was increased. CONCLUSIONS We concluded that the R56C mutant is responsible for type II HBS deficiency. We considered that the A459D and P112R mutants can be classified as belonging to the type I AT deficiency.
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Affiliation(s)
- Keiko Maruyama
- Department of Clinical Laboratory Science, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
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Wang J, Wang Y, Wang J, Gao J, Tong C, Manithody C, Li J, Rezaie AR. Antithrombin is protective against myocardial ischemia and reperfusion injury. J Thromb Haemost 2013; 11:1020-8. [PMID: 23582062 PMCID: PMC3702629 DOI: 10.1111/jth.12243] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Antithrombin (AT) is a plasma serpin inhibitor that regulates the proteolytic activity of procoagulant proteases of the clotting cascade. In addition to its anticoagulant activity, AT also possesses potent anti-inflammatory properties. OBJECTIVES The objective of this study was to investigate the anti-inflammatory activity of wild-type AT (AT-WT) and a reactive centre loop mutant of AT (AT-RCL) which is not capable of inhibiting thrombin. METHODS The cardioprotective activities of AT-WT and AT-RCL were monitored in a mouse model of ischemia/reperfusion (I/R) injury in which the left anterior descending coronary artery was occluded and then released. RESULTS We demonstrate that AT markedly reduces myocardial infarct size by a mechanism that is independent of its anticoagulant activity. Thus, AT-RCL attenuated myocardial infarct size to the same extent as AT-WT in this acute injury model. Further studies revealed that AT binds to vascular heparan sulfate proteoglycans via its heparin-binding domain to exert its protective activity as evidenced by the therapeutic AT-binding pentasaccharide (fondaparinux) abrogating the cardioprotective activity of AT and a heparin-site mutant of AT exhibiting no cardioprotective property. We further demonstrate that AT up-regulates the production of prostacyclin in myocardial tissues and inhibits expression of pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6 in vivo by attenuating ischemia/reperfusion-induced JNK and NF-κB signaling pathways. CONCLUSIONS The present results suggest that both AT and the non-anticoagulant AT-RCL, through their anti-inflammatory signaling effects, elicit potent cardioprotective responses. Thus, AT may have therapeutic potential for treating cardiac I/R injury.
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Affiliation(s)
- Jingying Wang
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Yanqing Wang
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Jinli Wang
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Junjie Gao
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Chao Tong
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Chandrashekhara Manithody
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO
| | - Ji Li
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo-SUNY, Buffalo, NY
| | - Alireza R. Rezaie
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO
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16
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Yang L, Ding Q, Huang X, Olson ST, Rezaie AR. Characterization of the heparin-binding site of the protein z-dependent protease inhibitor. Biochemistry 2012; 51:4078-85. [PMID: 22540147 DOI: 10.1021/bi300353c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High-molecular weight heparins promote the protein Z-dependent protease inhibitor (ZPI) inhibition of factors Xa (FXa) and XIa (FXIa) by a template mechanism. To map the heparin-binding site of ZPI, the role of basic residues of the D-helix (residues Lys-113, Lys-116, and Lys-125) in the interaction with heparin was evaluated by either substituting these residues with Ala (ZPI-3A) or replacing the D-helix with the corresponding loop of the non-heparin-binding serpin α(1)-proteinase inhibitor (ZPI-D-helix(α1-PI)). Furthermore, both the C-helix (contains two basic residues, Lys-104 and Arg-105) and the D-helix of ZPI were substituted with the corresponding loops of α(1)-proteinase inhibitor (ZPI-CD-helix(α1-PI)). All mutants exhibited near normal reactivity with FXa and FXIa in the absence of cofactors and in the presence of protein Z and membrane cofactors. By contrast, the mutants interacted with heparin with a lower affinity and the ~48-fold heparin-mediated enhancement in the rate of FXa inhibition by ZPI was reduced to ~30-fold for ZPI-3A, ~15-fold for ZPI-D-helix(α1-PI), and ~8-fold for ZPI-CD-helix(α1-PI). Consistent with a template mechanism for heparin cofactor action, ZPI-CD-helix(α1-PI) inhibition of a FXa mutant containing a mutation in the heparin-binding site (FXa-R240A) was minimally affected by heparin. A significant decrease (~2-5-fold) in the heparin template effect was also observed for the inhibition of FXIa by ZPI mutants. Interestingly, ZPI derivatives exhibited a markedly elevated stoichiometry of inhibition with FXIa in the absence of heparin. These results suggest that basic residues of both helices C and D of ZPI interact with heparin to modulate the inhibitory function of the serpin.
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Affiliation(s)
- Likui Yang
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA
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17
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Alexander KS, Fried MG, Farrell DH. Role of electrostatic interactions in binding of thrombin to the fibrinogen γ' chain. Biochemistry 2012; 51:3445-50. [PMID: 22439748 DOI: 10.1021/bi2016519] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thrombin binds to the highly anionic fibrinogen γ' chain through anion-binding exosite II. This binding profoundly alters thrombin's ability to cleave substrates, including fibrinogen, factor VIII, and PAR1. However, it is unknown whether this interaction is due mainly to general electrostatic complementarity between the γ' chain and exosite II or if there are critical charged γ' chain residues involved. We therefore systematically determined the contribution of negatively charged amino acids in the γ' chain, both individually and collectively, to thrombin binding affinity. Surface plasmon resonance binding experiments were performed using immobilized γ' chain peptides with charged-to-uncharged amino acid substitutions, i.e., Asp to Asn, Glu to Gln, and pTyr to Tyr. Individually, the substitution of uncharged for charged amino acids resulted in only minor changes in binding affinity, with a maximal change in K(d) from 0.440 to 0.705 μM for the Asp419Asn substitution. However, substitution of all three charged amino acids in a conserved β-turn that is predicted to contact thrombin, pTyr418Tyr, Asp419Asn, and pTyr422Tyr, resulted in the loss of measurable binding, as did substitution of all the flanking charged amino acids. In addition, the binding of the γ' chain to thrombin was weakened in a dose-dependent manner with increasing NaCl concentration, resulting in a net loss of three or four ion pairs between thrombin and the γ' chain. Therefore, although each of the individual charges in the γ' chain contributes only incrementally to the overall binding affinity, the ensemble of the combined charges plays a profound role in the thrombin-γ' chain interactions.
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Affiliation(s)
- Kristine S Alexander
- Department of Molecular and Medical Genetics, Oregon Health & Science University , Portland, OR 97239-3098, USA
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18
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Abstract
The molecular basis for the anticoagulant action of heparin lies in its ability to bind to and enhance the inhibitory activity of the plasma protein antithrombin against several serine proteases of the coagulation system, most importantly factors IIa (thrombin), Xa and IXa. Two major mechanisms underlie heparin's potentiation of antithrombin. The conformational changes induced by heparin binding cause both expulsion of the reactive loop and exposure of exosites of the surface of antithrombin, which bind directly to the enzyme target; and a template mechanism exists in which both inhibitor and enzyme bind to the same heparin molecule. The relative importance of these two modes of action varies between enzymes. In addition, heparin can act through other serine protease inhibitors such as heparin co-factor II, protein C inhibitor and tissue factor plasminogen inhibitor. The antithrombotic action of heparin in vivo, though dominated by anticoagulant mechanisms, is more complex, and interactions with other plasma proteins and cells play significant roles in the living vasculature.
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Affiliation(s)
- Elaine Gray
- National Institute for Biological Standards and Control, Potter's Bar, Hertfordshire, UK.
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Henry BL, Thakkar JN, Liang A, Desai UR. Sulfated, low molecular weight lignins inhibit a select group of heparin-binding serine proteases. Biochem Biophys Res Commun 2011; 417:382-6. [PMID: 22155248 DOI: 10.1016/j.bbrc.2011.11.122] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 11/22/2011] [Indexed: 11/20/2022]
Abstract
Sulfated low molecular weight lignins (LMWLs), designed as oligomeric mimetics of low molecular weight heparins (LMWHs), have been found to bind in exosite II of thrombin. To assess whether sulfated LMWLs recognize other heparin-binding proteins, we studied their effect on serine proteases of the coagulation, inflammatory and digestive systems. Using chromogenic substrate hydrolysis assay, sulfated LMWLs were found to potently inhibit coagulation factor XIa and human leukocyte elastase, moderately inhibit cathepsin G and not inhibit coagulation factors VIIa, IXa, and XIIa, plasma kallikrein, activated protein C, trypsin, and chymotrypsin. Competition studies show that UFH competes with sulfated LMWLs for binding to factors Xa and XIa. These results further advance the concept of sulfated LMWLs as heparin mimics and will aid the design of anticoagulants based on their novel scaffold.
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Affiliation(s)
- Brian L Henry
- Department of Medicinal Chemistry, Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, United States
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Martínez-Martínez I, Ordóñez A, Pedersen S, de la Morena-Barrio M, Navarro-Fernández J, Kristensen S, Miñano A, Padilla J, Vicente V, Corral J. Heparin affinity of factor VIIa: Implications on the physiological inhibition by antithrombin and clearance of recombinant factor VIIa. Thromb Res 2011; 127:154-60. [DOI: 10.1016/j.thromres.2010.11.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 11/02/2010] [Accepted: 11/08/2010] [Indexed: 11/25/2022]
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21
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Luxembourg B, Delev D, Geisen C, Spannagl M, Krause M, Miesbach W, Heller C, Bergmann F, Schmeink U, Grossmann R, Lindhoff-Last E, Seifried E, Oldenburg J, Pavlova A. Molecular basis of antithrombin deficiency. Thromb Haemost 2011; 105:635-46. [PMID: 21264449 DOI: 10.1160/th10-08-0538] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 01/16/2011] [Indexed: 11/05/2022]
Abstract
Antithrombin (AT) is the most important physiological inhibitor of coagulation proteases. It is activated by glycosaminoglycans such as heparin. Hereditary antithrombin deficiency is a rare disease that is mainly associated with venous thromboembolism. So far, more than 200 different mutations in the antithrombin gene (SERPINC1) have been described. The aim of our study was to characterise the molecular background in a large cohort of patients with AT deficiency. Mutation analysis was performed by direct sequencing of SERPINC1 in 272 AT-deficient patients. Large deletions were identified by multiplex PCR coupled with liquid chromatography or multiplex ligation-dependent probe amplification (MLPA) analysis. To predict the effect of SERPINC1 sequence variations on the pathogenesis of AT deficiency, in silico assessments, multiple sequence alignment, and molecular graphic imaging were performed. The mutation profile consisted of 59% missense, 10% nonsense, 8% splice site mutations, 15% small deletions/insertions/duplications, and 8% large deletions. Altogether 87 different mutations, including 42 novel mutations (22 missense and 20 null mutations), were identified. Of the novel missense mutations, nine are suspected to impair the conformational changes that are needed for AT activation, two to affect the central reactive loop or the heparin binding site, and six to impair the structural integrity of the molecule. Despite the heterogeneous background of AT deficiency, 10 AT variants occurred in multiple index patients. Characterisation of the SERPINC1 mutation profile in large cohorts of patients may help to further elucidate the pathogenesis of AT deficiency and to establish genotype-phenotype associations.
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Affiliation(s)
- Beate Luxembourg
- Institute of Transfusion Medicine and Immunohaematology, Department of Molecular Haemostaseology, DRK Blood Donor Service Baden-Württemberg-Hessen, Frankfurt, Germany.
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