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Yasmin R, Chanchal S, Ashraf MZ, Doley R. Daboxin P, a phospholipase A 2 of Indian Daboia russelii venom, modulates thrombin-mediated platelet aggregation. J Biochem Mol Toxicol 2023; 37:e23476. [PMID: 37466159 DOI: 10.1002/jbt.23476] [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: 12/10/2022] [Revised: 03/12/2023] [Accepted: 07/08/2023] [Indexed: 07/20/2023]
Abstract
Daboxin P, reported earlier from the venom of Daboia russellii, disturbs the blood coagulation cascade by targeting factor X and factor Xa. The present study exhibits that Daboxin P also inhibits platelet aggregation induced by various agonists. The thrombin-induced platelet aggregation was inhibited maximum whereas inhibition of collagen-induced platelet aggregation was found to be 50% and no inhibition of adenosine diphosphate (ADP) and arachidonic acid-induced aggregation was observed. Daboxin P dose-dependently inhibited the thrombin-induced platelet aggregation with Anti-Aggregation 50 (AD50 ) dose of 55.166 nM and also reduced the thrombin-mediated calcium influx. In-silico interaction studies suggested that Daboxin P binds to thrombin and blocks its interaction with its receptor on the platelet surface. Quenching of thrombin's emission spectrum by Daboxin P and electrophoretic profiles of pull-down assay further reveals the binding between Daboxin P and thrombin. Thus, the present study demonstrates that Daboxin P inhibits thrombin-induced platelet aggregation by binding to thrombin.
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Affiliation(s)
- Rafika Yasmin
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | - Shankar Chanchal
- Department of Biotechnology, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, New Delhi, India
| | - Mohammad Zahid Ashraf
- Department of Biotechnology, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, New Delhi, India
| | - Robin Doley
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
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2
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Mo Z, Xiao Z, He C. Functional expression of a thrombin exosite I inhibitor triabin in Escherichia coli and elucidation of the role of key residues in its inhibitory activity. Biochimie 2022; 208:13-19. [PMID: 36580989 DOI: 10.1016/j.biochi.2022.12.013] [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: 09/16/2022] [Revised: 12/03/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022]
Abstract
Triabin, a lipocalin-like thrombin inhibitor from the saliva of the blood-sucking triatomine bug Triatoma pallidipennis, exhibits effective inhibition comparable to hirudin despite binding exclusively at exosite I. Interestingly, it was reported that higher triabin doses would not inhibit thrombin completely, which makes it a promising antithrombotic candidate agent with a larger therapeutic window. However, few structural and functional studies about triabin have been reported in the past three decades, mostly due to the lack of a reliable and practicable recombinant expression technology for this seemingly small protein. In this work, we have adopted the SUMO fusion technology for the expression of triabin in E. coli cells-with facile refolding and purification procedures-and the bioactive triabin was produced in ∼12 mg/L culture medium. Subsequently, the structure-function studies through extensive site-directed mutagenesis reveal that triabin's Phe-106 involved in the hydrophobic contacts plays a surprisingly important role in the thrombin inhibition, in contrast to the negatively charged residues Asp-135 or Glu-128 involved in the salt-bridge interaction. As such, this study complements our understanding of the interaction mechanism of natural thrombin inhibitors, which should facilitate the development of anticoagulant drugs with a novel mode of action against thrombin.
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Affiliation(s)
- Zeyuan Mo
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China
| | - Zhenbang Xiao
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China
| | - Chunmao He
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China.
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3
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Jiao X, Xing Y, Wang H, Jin X, Zhang T, Peng X, Li R, Liang L, Liu R, Han L, Li Z. A strategy based on gene sequencing and molecular docking for analysis and prediction of bioactive peptides in Shuxuetong injection. Biophys Chem 2021; 282:106749. [PMID: 34971853 DOI: 10.1016/j.bpc.2021.106749] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 12/15/2022]
Abstract
Peptides are a class of protein fragments with relatively high biological activity and intense specificity, which play crucial role in the treatment of Shuxuetong injection (SXT). However, the extraordinary complexity of Chinese medicinal formulates and the lack of systematic identification methods are primary challenges for study of pharmacodynamic peptides. In addition, infinitesimal peptides contents further hinder the identification and structural characterization of polypeptide by traditional means. In this paper, we described a strategy that LC-MS combined with molecular docking to systematically illustrate the peptide components of SXT. The key to this research was used of gene sequencing to establish a SXT protein database to further achieve the separation and enrichment of chemical methods. Moreover, the ADRA2A, PAR4 and DRD3 were precisely docked with the identified peptides. The result indicated that 12 compounds had stable binding ability and were speculated to be the latent bioactive monomers for the treatment of stroke. Additionally, 12 peptides were verified by cell-based experiment. The results showed that only YLKTT could indeed protect astrocytes from oxygen glucose deprivation/reoxygenation (OGD/R). The YLKTT showed higher activity than the others in vitro. It might be a completely new compound that has never been reported before, providing the basis for further research and a new paradigm for stroke.
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Affiliation(s)
- Xinyi Jiao
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Yanchao Xing
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Haitao Wang
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Xin Jin
- Military Medicine Section, Logistics University of Chinese People's Armed Police Force, 1 Huizhihuan Road, Dongli District, Tianjin 300309, China
| | - Tingting Zhang
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Xingru Peng
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Rui Li
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Liuyi Liang
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China
| | - Rui Liu
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China.
| | - Lifeng Han
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China.
| | - Zheng Li
- State Key Laboratory of Component-based Chinese Medicine, Haihe Laboratory of Modern Chinese Medicine, College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 10 Poyang Lake Road, West Zone of Tuanbo New City, Jinghai District, Tianjin 301617, China.
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4
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Han X, Nieman MT. The domino effect triggered by the tethered ligand of the protease activated receptors. Thromb Res 2020; 196:87-98. [PMID: 32853981 DOI: 10.1016/j.thromres.2020.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/23/2020] [Accepted: 08/03/2020] [Indexed: 12/20/2022]
Abstract
Protease activated receptors (PARs) are G-protein coupled receptors (GPCRs) that have a unique activation mechanism. Unlike other GPCRs that can be activated by free ligands, under physiological conditions, PARs are activated by the tethered ligand, which is a part of their N-terminus that is unmasked by proteolysis. It has been 30 years since the first member of the family, PAR1, was identified. In this review, we will discuss this unique tethered ligand mediate receptor activation of PARs in detail: how they interact with the proteases, the complex structural rearrangement of the receptors upon activation, and the termination of the signaling. We also summarize the structural studies of the PARs and how single nucleotide polymorphisms impact the receptor reactivity. Finally, we review the current strategies for inhibiting PAR function with therapeutic targets for anti-thrombosis. The focus of this review is PAR1 and PAR4 as they are the thrombin signal mediators on human platelets and therapeutics targets. We also include the structural studies of PAR2 as it informs the mechanism of action for PARs in general.
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Affiliation(s)
- Xu Han
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Marvin T Nieman
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA.
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5
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Algar WR, Jeen T, Massey M, Peveler WJ, Asselin J. Small Surface, Big Effects, and Big Challenges: Toward Understanding Enzymatic Activity at the Inorganic Nanoparticle-Substrate Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7067-7091. [PMID: 30415548 DOI: 10.1021/acs.langmuir.8b02733] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Enzymes are important biomarkers for molecular diagnostics and targets for the action of drugs. In turn, inorganic nanoparticles (NPs) are of interest as materials for biological assays, biosensors, cellular and in vivo imaging probes, and vectors for drug delivery and theranostics. So how does an enzyme interact with a NP, and what are the outcomes of multivalent conjugation of its substrate to a NP? This invited feature article addresses the current state of the art in answering this question. Using gold nanoparticles (Au NPs) and semiconductor quantum dots (QDs) as illustrative materials, we discuss aspects of enzyme structure-function and the properties of NP interfaces and surface chemistry that determine enzyme-NP interactions. These aspects render the substrate-on-NP configurations far more complex and heterogeneous than the conventional turnover of discrete substrate molecules in bulk solution. Special attention is also given to the limitations of a standard kinetic analysis of the enzymatic turnover of these configurations, the need for a well-defined model of turnover, and whether a "hopping" model can account for behaviors such as the apparent acceleration of enzyme activity. A detailed and predictive understanding of how enzymes turn over multivalent NP-substrate conjugates will require a convergence of many concepts and tools from biochemistry, materials, and interface science. In turn, this understanding will help to enable rational, optimized, and value-added designs of NP bioconjugates for biomedical and clinical applications.
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Affiliation(s)
- W Russ Algar
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada
| | - Tiffany Jeen
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada
| | - Melissa Massey
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada
| | - William J Peveler
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada
- Division of Biomedical Engineering, School of Engineering , University of Glasgow , Glasgow G12 8LT , United Kingdom
| | - Jérémie Asselin
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada
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6
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Billur R, Sabo TM, Maurer MC. Thrombin Exosite Maturation and Ligand Binding at ABE II Help Stabilize PAR-Binding Competent Conformation at ABE I. Biochemistry 2019; 58:1048-1060. [PMID: 30672691 DOI: 10.1021/acs.biochem.8b00943] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Thrombin, derived from zymogen prothrombin (ProT), is a serine protease involved in procoagulation, anticoagulation, and platelet activation. Thrombin's actions are regulated through anion-binding exosites I and II (ABE I and ABE II) that undergo maturation during activation. Mature ABEs can utilize exosite-based communication to fulfill thrombin functions. However, the conformational basis behind such long-range communication and the resultant ligand binding affinities are not well understood. Protease activated receptors (PARs), involved in platelet activation and aggregation, are known to target thrombin ABE I. Unexpectedly, PAR3 (44-56) can already bind to pro-ABE I of ProT. Nuclear magnetic resonance (NMR) ligand-enzyme titrations were used to characterize how individual PAR1 (49-62) residues interact with pro-ABE I and mature ABE I. 1D proton line broadening studies demonstrated that binding affinities for native PAR1P (49-62, P54) and for the weak binding variant PAR1G (49-62, P54G) increased as ProT was converted to mature thrombin. 1H,15N-HSQC titrations revealed that PAR1G residues K51, E53, F55, D58, and E60 exhibited less affinity to pro-ABE I than comparable residues in PAR3G (44-56, P51G). Individual PAR1G residues then displayed tighter binding upon exosite maturation. Long-range communication between thrombin exosites was examined by saturating ABE II with phosphorylated GpIbα (269-282, 3Yp) and monitoring the binding of PAR1 and PAR3 peptides to ABE I. Individual PAR residues exhibited increased affinities in this dual-ligand environment supporting the presence of interexosite allostery. Exosite maturation and beneficial long-range allostery are proposed to help stabilize an ABE I conformation that can effectively bind PAR ligands.
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Affiliation(s)
- Ramya Billur
- Department of Chemistry , University of Louisville , Louisville , Kentucky 40292 , United States
| | - T Michael Sabo
- Department of Medicine, James Graham Brown Cancer Center , University of Louisville , Louisville , Kentucky 40202 , United States
| | - Muriel C Maurer
- Department of Chemistry , University of Louisville , Louisville , Kentucky 40292 , United States
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7
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Jeen T, Algar WR. Mimicking Cell Surface Enhancement of Protease Activity on the Surface of a Quantum Dot Nanoparticle. Bioconjug Chem 2018; 29:3783-3792. [DOI: 10.1021/acs.bioconjchem.8b00647] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Tiffany Jeen
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - W. Russ Algar
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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8
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Choi HJ, Kim NE, Kim J, An S, Yang SH, Ha J, Cho S, Kwon I, Kim YD, Nam HS, Heo JH. Dabigatran reduces endothelial permeability through inhibition of thrombin-induced cytoskeleton reorganization. Thromb Res 2018; 167:S0049-3848(18)30324-4. [PMID: 29735342 DOI: 10.1016/j.thromres.2018.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/28/2018] [Accepted: 04/18/2018] [Indexed: 11/23/2022]
Abstract
Dabigatran etexilate (DE), a new oral anti-coagulant, is a direct thrombin inhibitor. Clinical trials showed the favorable benefit-to-risk profile of DE compared to warfarin for the prevention of ischemic stroke in patients with atrial fibrillation. Remarkably, patients treated with dabigatran showed reduced rates of intracerebral hemorrhage compared to warfarin. As the breakdown of endothelial barrier integrity is associated with hemorrhagic events and as thrombin increases endothelial permeability, we hypothesized that dabigatran preserves the endothelial barrier by inhibiting thrombin-induced permeability. We assessed leakage of fluorescein isothiocyanate (FITC)-dextran through the endothelial monolayer and measured trans-endothelial electrical resistance of the endothelial monolayer after treatment of thrombin or thrombin pre-incubated with dabigatran. Thrombin increased the permeability of endothelial cells. Dabigatran effectively blocked the ability of thrombin to increase permeability. Dabigatran inhibited the formation of actin stress fibers induced by thrombin and inhibited consequent destabilization of junctional protein complexes and intercellular gap formation. The interaction of thrombin with protease activated receptor-1 activates the Rho A guanosine triphosphate (GTP)ase-myosin light chain (MLC) phosphorylation signaling axis, leading to actin cytoskeleton changes. This signaling pathway was effectively inhibited by dabigatran in endothelial cells. Consistently, the number of phosphorylated MLC-positive cells was significantly decreased in ischemic tissue of rat brains. These results indicate dabigatran blocks the ability of thrombin to induce vascular permeability and the resulting underlying signaling cascade in endothelial cells. Our findings provide evidence that dabigatran may confer a lower risk of intracerebral hemorrhage by preserving endothelial barrier integrity.
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Affiliation(s)
- Hyun-Jung Choi
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Na-Eun Kim
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jayoung Kim
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sunho An
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, Seoul 03722, Republic of Korea
| | - Seung-Hee Yang
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jimin Ha
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, Seoul 03722, Republic of Korea
| | - Sunghee Cho
- The Burke-Cornell Medical Research Institute, White Plains, NY 10605, United States; Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10021, United States
| | - Il Kwon
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Dae Kim
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyo Suk Nam
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji Hoe Heo
- Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, Seoul 03722, Republic of Korea.
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9
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Mirabegron, a β 3-adrenoceptor agonist reduced platelet aggregation through cyclic adenosine monophosphate accumulation. Eur J Pharmacol 2018; 829:79-84. [PMID: 29654782 DOI: 10.1016/j.ejphar.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 04/05/2018] [Accepted: 04/09/2018] [Indexed: 11/22/2022]
Abstract
Mirabegron is a β3-adrenoceptor agonist and released on the marked for the treatment of overactive bladder. Because mirabegron is the only β3-adrenoceptor agonist available and substances that increase the levels of cyclic adenosine monophosphate (cAMP) inhibit platelet activity, we tested the hypothesis that mirabegron could have antiplatelet activity. Collagen- and thrombin induced platelet aggregation, thromboxane B2 (TXB2) and cyclic nucleotides quantification and calcium (Ca2+) mobilization were determined in the absence and presence of mirabegron in human washed platelets. Our results revealed that mirabegron (10-300 µM) produced significant inhibitions on platelet aggregation induced by collagen- or thrombin, accompanied by greater intracellular levels of cAMP. The β3-adrenoceptor antagonist L 748,337 (1 µM) and the adenylate cyclase inhibitor, SQ 22,536 (100 µM) reversed the inhibition induced by mirabegron in thrombin-stimulated platelets. The selective antagonists for β1-and β2-adrenoceptors, atenolol and ICI 117,551 (3 µM), respectively did not interfere on the inhibition induced by mirabegron. In Fluo-4 loaded platelets, mirabegron reduced the total and intracellular Ca2+ levels. Pre-incubation with mirabegron almost abolished the levels of TXB2. Mirabegron did not augment the intracellular levels of cyclic guanosine monophosphate. In conclusion, mirabegron inhibited human platelet aggregation through cAMP accumulation, thus suggesting that substances that activate β3-adrenoceptor could be beneficial as adjuvant antiplatelet therapy.
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10
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Boudreaux MK, Barnes SM. Comparison of the activation peptide regions of protease-activated receptors (PAR) in members of the Family Felidae. Vet Clin Pathol 2016; 45:400-5. [PMID: 27291980 DOI: 10.1111/vcp.12371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND There is limited information regarding the nucleotides encoding or the predicted amino acid composition of protease-activated receptors (PAR) in cats. OBJECTIVES The purpose of the study was to determine the nucleotide sequence and predicted amino acid composition of the activation peptide regions of protease-activated receptors PAR1, PAR3, and PAR4 in Felidae family members. METHODS Genomic DNA isolated from whole blood samples collected from 10 domestic cats and 45 big cats representing 11 species was subjected to PCR using primers flanking the coding regions for the activation peptides of PAR1, PAR3, and PAR4. PCR products were isolated from agarose gels and submitted for sequencing. Nucleotide sequence data was used to predict the amino acid composition of the activation peptide and flanking regions of the 3 receptors. Predicted amino acid sequences were compared between Felidae members and to human beings. RESULTS Variations in the predicted amino acid composition of the activation peptides and flanking regions of the various PAR were observed when comparing Felidae family members to each other and to human beings. CONCLUSIONS While the activation peptide regions of the various PAR tend to be conserved, there are differences that may impact the ability of some agonists to mediate biased signaling events documented to occur in human platelets.
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Affiliation(s)
- Mary K Boudreaux
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.
| | - Sara Madison Barnes
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
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11
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Chen B, Soto AG, Coronel LJ, Goss A, van Ryn J, Trejo J. Characterization of thrombin-bound dabigatran effects on protease-activated receptor-1 expression and signaling in vitro. Mol Pharmacol 2015; 88:95-105. [PMID: 25934730 DOI: 10.1124/mol.114.096446] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 04/30/2015] [Indexed: 12/15/2022] Open
Abstract
Thrombin, the key effector protease of the coagulation cascade, drives fibrin deposition and activates human platelets through protease-activated receptor-1 (PAR1). These processes are critical to the progression of thrombotic diseases. Thrombin is the main target of anticoagulant therapy, and major efforts have led to the discovery of new oral direct inhibitors of thrombin. Dabigatran is the first oral anticoagulant licensed for the prevention of thromboembolisms associated with orthopedic surgery and stroke prevention in atrial fibrillation. Dabigatran is a direct thrombin inhibitor that effectively blocks thrombin's catalytic activity but does not preclude thrombin's exosites and binding to fibrinogen. Thus, we hypothesized that catalytically inactive thrombin retains the capacity to bind to PAR1 through exosite-I and may modulate its function independent of receptor cleavage and activation. Here, we report that dabigatran at clinically relevant concentrations is an effective and acute inhibitor of thrombin-induced PAR1 cleavage, activation, internalization, and β-arrestin recruitment in vitro. Interestingly, prolonged exposure to catalytic inactive thrombin incubated with dabigatran at 20-fold higher therapeutic concentration resulted in increased PAR1 cell-surface expression, which correlated with higher detectable levels of ubiquitinated receptor. These findings are consistent with ubiquitin function as a negative regulator of PAR1 constitutive internalization. Increased PAR1 expression also enhanced agonist-induced phosphoinositide hydrolysis and endothelial barrier permeability. Thus, catalytically inactive thrombin appears to modulate PAR1 function in vitro by stabilizing receptor cell-surface expression; but given the high clearance rate of thrombin, the high concentration of dabigatran required to achieve this effect the in vivo physiologic relevance is unknown.
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Affiliation(s)
- Buxin Chen
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
| | - Antonio G Soto
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
| | - Luisa J Coronel
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
| | - Ashley Goss
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
| | - Joanne van Ryn
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
| | - JoAnn Trejo
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California (B.C., A.G.C., L.J.C., J.T.); Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut (A.G.); and Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma Gmbh, Biberach, Germany (J.R.)
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12
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Li YJ, Chiu WJ, Unnikrishnan B, Huang CC. Monitoring thrombin generation and screening anticoagulants through pulse laser-induced fragmentation of biofunctional nanogold on cellulose membranes. ACS APPLIED MATERIALS & INTERFACES 2014; 6:15253-15261. [PMID: 25141032 DOI: 10.1021/am503615c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Thrombin generation (TG) has an important part in the blood coagulation system, and monitoring TG is useful for diagnosing various health issues related to hypo-coagulability and hyper-coagulability. In this study, we constructed probes by using mixed cellulose ester membranes (MCEMs) modified with gold nanoparticles (Au NPs) for monitoring thrombin activity using laser desorption/ionization mass spectrometry (LDI-MS). The LDI process produced Au cationic clusters ([Au(n)](+); n = 1-3) that we detected through MS. When thrombin reacted with fibrinogen on the Au NPs-MCEMs, insoluble fibrin was formed, hindering the formation of Au cationic clusters and, thereby, decreasing the intensity of their signals in the mass spectrum. Accordingly, we incorporated fibrinogen onto the Au NPs-MCEMs to form Fib-Au NPs-MCEM probes to monitor TG with good selectivity (>1000-fold toward thrombin with respect to other proteins or enzymes) and sensitivity (limit of detection for thrombin of ca. 2.5 pM in human plasma samples). Our probe exhibited remarkable performance in monitoring the inhibition of thrombin activity by direct thrombin inhibitors. Analyses of real samples using our new membrane-based probe suggested that it will be highly useful in practical applications for the effective management of hemostatic complications.
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Affiliation(s)
- Yu-Jia Li
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University , Keelung 20224, Taiwan
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Boechi L, Pierce L, Komives EA, McCammon JA. Trypsinogen activation as observed in accelerated molecular dynamics simulations. Protein Sci 2014; 23:1550-8. [PMID: 25131668 DOI: 10.1002/pro.2532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 06/17/2014] [Accepted: 08/03/2014] [Indexed: 11/07/2022]
Abstract
Serine proteases are involved in many fundamental physiological processes, and control of their activity mainly results from the fact that they are synthetized in an inactive form that becomes active upon cleavage. Three decades ago Martin Karplus's group performed the first molecular dynamics simulations of trypsin, the most studied member of the serine protease family, to address the transition from the zymogen to its active form. Based on the computational power available at the time, only high frequency fluctuations, but not the transition steps, could be observed. By performing accelerated molecular dynamics (aMD) simulations, an interesting approach that increases the configurational sampling of atomistic simulations, we were able to observe the N-terminal tail insertion, a crucial step of the transition mechanism. Our results also support the hypothesis that the hydrophobic effect is the main force guiding the insertion step, although substantial enthalpic contributions are important in the activation mechanism. As the N-terminal tail insertion is a conserved step in the activation of serine proteases, these results afford new perspective on the underlying thermodynamics of the transition from the zymogen to the active enzyme.
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Affiliation(s)
- Leonardo Boechi
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California
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Heng BC, Aubel D, Fussenegger M. An overview of the diverse roles of G-protein coupled receptors (GPCRs) in the pathophysiology of various human diseases. Biotechnol Adv 2013; 31:1676-94. [DOI: 10.1016/j.biotechadv.2013.08.017] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/19/2013] [Accepted: 08/19/2013] [Indexed: 12/23/2022]
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Palma-Nicolás JP, López-Colomé AM. Thrombin induces slug-mediated E-cadherin transcriptional repression and the parallel up-regulation of N-cadherin by a transcription-independent mechanism in RPE cells. J Cell Physiol 2013; 228:581-9. [PMID: 22833386 DOI: 10.1002/jcp.24165] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/17/2012] [Indexed: 12/14/2022]
Abstract
The proliferation, directional migration to the vitreous and epithelial-mesenchymal transition (EMT) of quiescent, differentiated retinal pigment epithelium (RPE) cells is a major feature in the development of proliferative vitreoretinopathy (PVR) following exposure of the immuno-privileged eye niche to serum components, thrombin among them. We have previously documented thrombin induction of RPE cell proliferation and migration. We here analyzed the effect of thrombin on the E/N cadherin switch, a hallmark of EMT. Results show that thrombin induces the specific repression of epithelial E-cadherin gene transcription, alongside with the up-regulation of mesenchymal N-cadherin protein in RPE cells. We demonstrate, for the first time, that thrombin induces E-cadherin repression by stimulating snail-2 (SLUG) transcription factor expression, and the concomitant up-regulation of N-cadherin through the transcription-independent increase in protein translation promoted by PI3K/PKC-ζ/mTOR signaling. Our present findings suggest that the activation of protease-activated receptor-1 (PAR-1) by thrombin induces EMT of RPE cells, further supporting a central role for thrombin in PVR pathogenesis.
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Affiliation(s)
- José Prisco Palma-Nicolás
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, DF, Mexico
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16
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Protease-Activated Receptors. Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00013-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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17
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Platelet biogenesis and functions require correct protein O-glycosylation. Proc Natl Acad Sci U S A 2012; 109:16143-8. [PMID: 22988088 DOI: 10.1073/pnas.1208253109] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Platelets express a variety of membrane and secreted glycoproteins, but the importance of glycosylation to platelet functions is poorly understood. To explore the importance of O-glycosylation, we generated mice with a targeted deletion of Cosmc in murine endothelial/hematopoietic cells (EHC) (EHC Cosmc(-/y)). X-linked Cosmc encodes an essential chaperone that regulates protein O-glycosylation. This targeted mutation resulted in lethal perinatal hemorrhage in the majority of mice, and the surviving mice displayed severely prolonged tail-bleeding times and macrothrombocytopenia. EHC Cosmc(-/y) platelets exhibited a marked decrease in GPIb-IX-V function and agonist-mediated integrin αIIbβ3 activation, associated with loss of interactions with von Willebrand factor and fibrinogen, respectively. Significantly, three O-glycosylated glycoproteins, GPIbα, αIIb, and GPVI normally on platelet surfaces that play essential roles in platelet functions, were partially proteolyzed in EHC Cosmc(-/y) platelets. These results demonstrate that extended O-glycans are required for normal biogenesis of the platelets as well as the expression and functions of their essential glycoproteins, and that variations in O-glycosylation may contribute to altered hemostasis.
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18
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Ponczek MB, Bijak MZ, Nowak PZ. Evolution of thrombin and other hemostatic proteases by survey of protochordate, hemichordate, and echinoderm genomes. J Mol Evol 2012; 74:319-31. [PMID: 22752046 DOI: 10.1007/s00239-012-9509-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 06/12/2012] [Indexed: 11/25/2022]
Abstract
Protochordate genomes enable a prevalence of hemostasis evolution. Broad searches were performed for homologs of human serine proteases of hemostasis on the genomes of Branchiostoma floridae, Saccoglossus kowalevskii, and Strongylocentrotus purpuratus. Sequences were analyzed by multiple bioinformatic tools. The survey revealed numerous homologous components. Amphioxus was rich in some serine proteases not accompanied by gamma-carboxyglutamic or kringle domains similar more to thrombin than to other coagulation factors. The serine proteases found in amphioxus exhibited the attributes similar to those of thrombin by phylogeny relationships, sequence conservation, gene synteny, spatial structure, and ligand docking. A few plasminogen- and plasminogen activators-like proteases with kringles were also present. Those serine proteases demonstrated the greatest proximity rather to plasminogen or plasminogen activators than to thrombin. Searching for homologs of serine protease hemostatic factors in acorn worm and sea urchin revealed several components similar to those found in amphioxus. Hypothetically, the common ancestor of chordates had three separate serine proteases that evolved independently into immunoglobulin-like and kringle proteases in lancelets, and prothrombin, plasminogen activators, and plasminogen in vertebrates. Ancestral proteases evolved in vertebrates into hemostasis factors after merging the proper N-terminal domains and duplications.
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Affiliation(s)
- Michal B Ponczek
- Department of General Biochemistry, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
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19
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Abstract
Protein C is activated by thrombin with a value of k(cat)/K(m) = 0.11mM(-1)s(-1) that increases 1700-fold in the presence of the cofactor thrombomodulin. The molecular origin of this effect triggering an important feedback loop in the coagulation cascade remains elusive. Acidic residues in the activation domain of protein C are thought to electrostatically clash with the active site of thrombin. However, functional and structural data reported here support an alternative scenario. The thrombin precursor prethrombin-2 has R15 at the site of activation in ionic interaction with E14e, D14l, and E18, instead of being exposed to solvent for proteolytic attack. Residues E160, D167, and D172 around the site of activation at R169 of protein C occupy the same positions as E14e, D14l, and E18 in prethrombin-2. Caging of R169 by E160, D167, and D172 is responsible for much of the poor activity of thrombin toward protein C. The E160A/D167A/D172A mutant is activated by thrombin 63-fold faster than wild-type in the absence of thrombomodulin and, over a slower time scale, spontaneously converts to activated protein C. These findings establish a new paradigm for cofactor-assisted reactions in the coagulation cascade.
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Cunningham MR, McIntosh KA, Pediani JD, Robben J, Cooke AE, Nilsson M, Gould GW, Mundell S, Milligan G, Plevin R. Novel role for proteinase-activated receptor 2 (PAR2) in membrane trafficking of proteinase-activated receptor 4 (PAR4). J Biol Chem 2012; 287:16656-69. [PMID: 22411985 PMCID: PMC3351358 DOI: 10.1074/jbc.m111.315911] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Proteinase-activated receptors 4 (PAR4) is a class A G protein-coupled receptor (GPCR) recognized through the ability of serine proteases such as thrombin and trypsin to mediate receptor activation. Due to the irreversible nature of activation, a fresh supply of receptor is required to be mobilized to the cell surface for responsiveness to agonist to be sustained. Unlike other PAR subtypes, the mechanisms regulating receptor trafficking of PAR4 remain unknown. Here, we report novel features of the intracellular trafficking of PAR4 to the plasma membrane. PAR4 was poorly expressed at the plasma membrane and largely retained in the endoplasmic reticulum (ER) in a complex with the COPI protein subunit β-COP1. Analysis of the PAR4 protein sequence identified an arginine-based (RXR) ER retention sequence located within intracellular loop-2 (R183AR → A183AA), mutation of which allowed efficient membrane delivery of PAR4. Interestingly, co-expression with PAR2 facilitated plasma membrane delivery of PAR4, an effect produced through disruption of β-COP1 binding and facilitation of interaction with the chaperone protein 14-3-3ζ. Intermolecular FRET studies confirmed heterodimerization between PAR2 and PAR4. PAR2 also enhanced glycosylation of PAR4 and activation of PAR4 signaling. Our results identify a novel regulatory role for PAR2 in the anterograde traffic of PAR4. PAR2 was shown to both facilitate and abrogate protein interactions with PAR4, impacting upon receptor localization and cell signal transduction. This work is likely to impact markedly upon the understanding of the receptor pharmacology of PAR4 in normal physiology and disease.
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Affiliation(s)
- Margaret R Cunningham
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, Univesity of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, Scotland, United Kingdom.
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Clemetson KJ. Platelets and primary haemostasis. Thromb Res 2011; 129:220-4. [PMID: 22178577 DOI: 10.1016/j.thromres.2011.11.036] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/20/2011] [Accepted: 11/22/2011] [Indexed: 12/11/2022]
Abstract
Platelets have a critical role in haemostasis when vessel wall is injured. Platelet receptors are involved in sequence in this process by slowing platelets down via GPIb/von Willebrand factor to bring them into contact with exposed collagen, then activating them via GPVI to release granule contents and express integrins in a matrix protein binding state. More platelets are incorporated into the growing thrombus and a series of events are set off that finishes with the exposed subendothelium protected by a non-thrombogenic platelet surface and tissue repair underway and the blood flow through the vessel maintained. GPIb is also involved in thrombin activation and, together with GPVI, in the formation of COAT platelets. In thrombosis, pathological changes occur that may lead to life-threatening blockage of vessels. Prevention of thrombosis while maintaining haemostasis remains a major goal of medical research.
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Affiliation(s)
- Kenneth J Clemetson
- Department of Haematology, Inselspital, University of Berne, CH-3010 Berne, Switzerland.
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