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Soslau G. Platelet protein synthesis, regulation, and post-translational modifications: mechanics and function. Crit Rev Biochem Mol Biol 2023; 58:99-117. [PMID: 37347996 DOI: 10.1080/10409238.2023.2224532] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/08/2023] [Indexed: 06/24/2023]
Abstract
Dogma had been firmly entrenched in the minds of the scientific community that the anucleate mammalian platelet was incapable of protein biosynthesis since their identification in the late 1880s. These beliefs were not challenged until the 1960s when several reports demonstrated that platelets possessed the capacity to biosynthesize proteins. Even then, many still dismissed the synthesis as trivial and unimportant for at least another two decades. Research in the field expanded after the 1980s and numerous reports have since been published that now clearly demonstrate the potential significance of platelet protein synthesis under normal, pathological, and activating conditions. It is now clear that the platelet proteome is not a static entity but can be altered slowly or rapidly in response to external signals to support physiological requirements to maintain hemostasis and other biological processes. All the necessary biological components to support protein synthesis have been identified in platelets along with post-transcriptional processing of mRNAs, regulators of translation, and post-translational modifications such as glycosylation. The last comprehensive review of the subject appeared in 2009 and much work has been conducted since that time. The current review of the field will briefly incorporate the information covered in earlier reviews and then bring the reader up to date with more recent findings.
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Affiliation(s)
- Gerald Soslau
- Department of Biochemistry and Molecular Biology Drexel University College of Medicine, Philadelphia, PA, United States
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2
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Fedchenko V, Veselovsky A, Kopylov A, Kaloshina S, Medvedev A. Renalase may be cleaved in blood. Are blood chymotrypsin-like enzymes involved? Med Hypotheses 2022; 165:110895. [DOI: 10.1016/j.mehy.2022.110895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Allan HE, Hayman MA, Marcone S, Chan MV, Edin ML, Maffucci T, Joshi A, Menke L, Crescente M, Mayr M, Zeldin DC, Armstrong PC, Warner TD. Proteome and functional decline as platelets age in the circulation. J Thromb Haemost 2021; 19:3095-3112. [PMID: 34390534 PMCID: PMC8604765 DOI: 10.1111/jth.15496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/28/2021] [Accepted: 08/11/2021] [Indexed: 01/20/2023]
Abstract
BACKGROUND Platelets circulate in the blood of healthy individuals for approximately 7-10 days regulated by finely balanced processes of production and destruction. As platelets are anucleate we reasoned that their protein composition would change as they age and that this change would be linked to alterations in structure and function. OBJECTIVE To isolate platelets of different ages from healthy individuals to test the hypothesis that changes in protein content cause alterations in platelet structure and function. METHODS Platelets were separated according to thiazole orange fluorescence intensity as a surrogate indicator of mRNA content and so a marker of platelet age and then subjected to proteomics, imaging, and functional assays to produce an in-depth analysis of platelet composition and function. RESULTS Total protein content was 45 ± 5% lower in old platelets compared to young platelets. Predictive proteomic pathway analysis identified associations with 28 biological processes, notably higher hemostasis in young platelets whilst apoptosis and senescence were higher in old platelets. Further studies confirmed platelet ageing was linked to a decrease in cytoskeletal protein and associated capability to spread and adhere, a reduction in mitochondria number, and lower calcium dynamics and granule secretion. CONCLUSIONS Our findings demonstrate changes in protein content are linked to alterations in function as platelets age. This work delineates physical and functional changes in platelets as they age and serves as a base to examine differences associated with altered mean age of platelet populations in conditions such as immune thrombocytopenia and diabetes.
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Affiliation(s)
- Harriet E. Allan
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Melissa A. Hayman
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Simone Marcone
- Department of Surgery, Trinity Translational Medicine Institute, Trinity College Dublin, Dublin, Ireland
| | - Melissa V. Chan
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Matthew L. Edin
- National Institutes of Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Tania Maffucci
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Abhishek Joshi
- King’s British Heart Foundation Centre, Kings College London, London, United Kingdom
| | - Laura Menke
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Marilena Crescente
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Manuel Mayr
- King’s British Heart Foundation Centre, Kings College London, London, United Kingdom
| | - Darryl C. Zeldin
- National Institutes of Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Paul C. Armstrong
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Timothy D. Warner
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
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Colberg L, Cammann C, Wesche J, Topfstedt E, Seifert U, Greinacher A. The platelet proteasome and immunoproteasome are stable in buffy-coat derived platelet concentrates for up to 7 days. Transfusion 2021; 61:2746-2755. [PMID: 34331776 DOI: 10.1111/trf.16605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 06/20/2021] [Accepted: 06/27/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Characterization of the proteasome and its stability in buffy-coat derived platelet concentrates (PCs) during storage. BACKGROUND The proteasome plays a key role in cell homeostasis by processing misfolded or abnormal proteins and regulating the levels and activities of a high number of proteins contributing to cell cycle, survival, and proliferation. Controversial data exist, whether inhibition of the proteasome affects platelet function. Little is known about function, expression, and stability of the proteasome in PCs during storage, and the potential role of the platelet proteasome in storage lesions. STUDY DESIGN AND METHODS PCs were produced by the buffy-coat method in additive solution and stored at room temperature under agitation. Platelet aggregation was monitored by light transmission aggregometry. Proteasome complexes were assessed by immunoprecipitation and immunoblotting, and proteasome activity was measured using fluorogenic substrates specific for the three different proteolytic activities over 7 days of storage. RESULTS Proteasome inhibition led to a decreased platelet aggregation response after activation with collagen, ADP, TRAP-6, and thrombin. There were no changes in the expression of the catalytic active subunits as well as the proteasome activity during storage of PCs, comparing baseline and day 7. DISCUSSION Platelet proteasome function is relevant for platelet aggregation in response to various agonists. The constitutive and stable expression of the active standard- and immunoproteasome in platelets makes it unlikely that loss of proteasome function is a relevant cause of storage lesions.
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Affiliation(s)
- Lisa Colberg
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany.,Friedrich Loeffler-Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Clemens Cammann
- Friedrich Loeffler-Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Jan Wesche
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Eylin Topfstedt
- Friedrich Loeffler-Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Ulrike Seifert
- Friedrich Loeffler-Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Andreas Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
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El-Kadiry AEH, Merhi Y. The Role of the Proteasome in Platelet Function. Int J Mol Sci 2021; 22:ijms22083999. [PMID: 33924425 PMCID: PMC8069084 DOI: 10.3390/ijms22083999] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Platelets are megakaryocyte-derived acellular fragments prepped to maintain primary hemostasis and thrombosis by preserving vascular integrity. Although they lack nuclei, platelets harbor functional genomic mediators that bolster platelet activity in a signal-specific manner by performing limited de novo protein synthesis. Furthermore, despite their limited protein synthesis, platelets are equipped with multiple protein degradation mechanisms, such as the proteasome. In nucleated cells, the functions of the proteasome are well established and primarily include proteostasis among a myriad of other signaling processes. However, the role of proteasome-mediated protein degradation in platelets remains elusive. In this review article, we recapitulate the developing literature on the functions of the proteasome in platelets, discussing its emerging regulatory role in platelet viability and function and highlighting how its functional coupling with the transcription factor NF-κB constitutes a novel potential therapeutic target in atherothrombotic diseases.
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Affiliation(s)
- Abed El-Hakim El-Kadiry
- Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, Montreal, QC H1T 1C8, Canada;
- Biomedical Sciences Program, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Yahye Merhi
- Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Research Centre, Montreal, QC H1T 1C8, Canada;
- Biomedical Sciences Program, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
- Correspondence: ; Tel.: +1-514-376-3330
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Kraemer BF, Geimer M, Franz-Wachtel M, Lamkemeyer T, Mannell H, Lindemann S. Extracellular Matrix-Specific Platelet Activation Leads to a Differential Translational Response and Protein De Novo Synthesis in Human Platelets. Int J Mol Sci 2020; 21:ijms21218155. [PMID: 33142786 PMCID: PMC7672557 DOI: 10.3390/ijms21218155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 02/08/2023] Open
Abstract
Platelets are exposed to extracellular matrix (ECM) proteins like collagen and laminin and to fibrinogen during acute vascular events. However, beyond hemostasis, platelets have the important capacity to migrate on ECM surfaces, but the translational response of platelets to different extracellular matrix stimuli is still not fully characterized. Using 2D-gel electrophoresis, confocal microscopy, polysome analysis and protein sequencing by mass spectrometry, we demonstrate that platelets show a differential expression profile of newly synthesized proteins on laminin, collagen or fibrinogen. In this context, we observed a characteristic, ECM-dependent translocation phenotype of translation initiation factor eIF4E to the ribosomal site. eIF4E accumulated in polysomes with increased binding of mRNA and co-localization with vinculin, leading to de novo synthesis of important cytoskeletal regulator proteins. As the first study, we included a proteome analysis of laminin-adherent platelets and interestingly identified upregulation of essentially important proteins that mediate cytoskeletal regulation and mobility in platelets, such as filamin A, talin, vinculin, gelsolin, coronin or kindlin-3. In summary, we demonstrate that platelet activation with extracellular matrix proteins results in a distinct stimulus-specific translational response of platelets that will help to improve our understanding of the regulation of platelet mobility and migration.
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Affiliation(s)
- Bjoern F. Kraemer
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Marchioninistrasse 15, 81377 Munich, Germany;
| | - Marc Geimer
- Klinik für Anästhesie, Intensiv- und Notfallmedizin, Westpfalz Klinikum Kaiserslautern, Hellmut-Hartert Str. 1, 67655 Kaiserslautern, Germany;
| | - Mirita Franz-Wachtel
- Proteasome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany;
| | - Tobias Lamkemeyer
- Cluster of Excellence Cologne (CEDAD), Mass Spectrometry Facility at the Institute for Genetics, University of Köln, Josef-Stelzmann-Str. 26, 50931 Köln, Germany;
| | - Hanna Mannell
- Doctoral Programme of Clinical Pharmacy, University Hospital, Ludwig-Maximilians-University, Marchioninistr. 27, 81377 Munich, Germany;
- Institute of Cardiovascular Physiology and Pathophysiology Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, 82152 Planegg, Germany
| | - Stephan Lindemann
- Philipps Universität Marburg, FB 20-Medizin, Baldingerstraße, 35032 Marburg, Germany
- Klinikum Warburg, Medizinische Klinik II, Hüffertstr. 50, 34414 Warburg, Germany
- Medizinische Klinik und Poliklinik III, Otfried-Muller-Str. 10, Universitätsklinikum Tübingen, 72076 Tübingen, Germany
- Correspondence:
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Colberg L, Cammann C, Greinacher A, Seifert U. Structure and function of the ubiquitin-proteasome system in platelets. J Thromb Haemost 2020; 18:771-780. [PMID: 31898400 DOI: 10.1111/jth.14730] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/30/2019] [Indexed: 12/16/2022]
Abstract
Platelets are small anucleate blood cells with a life span of 7 to 10 days. They are main regulators of hemostasis. Balanced platelet activity is crucial to prevent bleeding or occlusive thrombus formation. Growing evidence supports that platelets also participate in immune reactions, and interaction between platelets and leukocytes contributes to both thrombosis and inflammation. The ubiquitin-proteasome system (UPS) plays a key role in maintaining cellular protein homeostasis by its ability to degrade non-functional self-, foreign, or short-lived regulatory proteins. Platelets express standard and immunoproteasomes. Inhibition of the proteasome impairs platelet production and platelet function. Platelets also express major histocompatibility complex (MHC) class I molecules. Peptide fragments released by proteasomes can bind to MHC class I, which makes it also likely that platelets can activate epitope specific cytotoxic T lymphocytes (CTLs). In this review, we focus on current knowledge on the significance of the proteasome for the functions of platelets as critical regulators of hemostasis as well as modulators of the immune response.
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Affiliation(s)
- Lisa Colberg
- Friedrich Loeffler Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Clemens Cammann
- Friedrich Loeffler Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Andreas Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Ulrike Seifert
- Friedrich Loeffler Institut für Medizinische Mikrobiologie-Virologie, Universitätsmedizin Greifswald, Greifswald, Germany
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8
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Grundler Groterhorst K, Mannell H, Pircher J, Kraemer BF. Platelet Proteasome Activity and Metabolism Is Upregulated during Bacterial Sepsis. Int J Mol Sci 2019; 20:E5961. [PMID: 31783490 DOI: 10.3390/ijms20235961] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 11/30/2022] Open
Abstract
Dysregulation of platelet function can contribute to the disease progression in sepsis. The proteasome represents a critical and vital element of cellular protein metabolism in platelets and its proteolytic activity has been associated with platelet function. However, the role of the platelet proteasome as well as its response to infection under conditions of sepsis have not been studied so far. We measured platelet proteasome activity by fluorescent substrates, degradation of poly-ubiquitinated proteins and cleavage of the proteasome substrate Talin-1 in the presence of living E. coli strains and in platelets isolated from sepsis patients. Upregulation of the proteasome activator PA28 (PSME1) was assessed by quantitative real-time PCR in platelets from sepsis patients. We show that co-incubation of platelets with living E. coli (UTI89) results in increased degradation of poly-ubiquitinated proteins and cleavage of Talin-1 by the proteasome. Proteasome activity and cleavage of Talin-1 was significantly increased in α-hemolysin (HlyA)-positive E. coli strains. Supporting these findings, proteasome activity was also increased in platelets of patients with sepsis. Finally, the proteasome activator PA28 (PSME1) was upregulated in this group of patients. In this study we demonstrate for the first time that the proteasome in platelets is activated in the septic milieu.
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Berger M, Lutz DRJ, Lutz J, Khalil JS, Aburima A, Naseem KM, Rivero F. Alterations in Platelet Alpha-Granule Secretion and Adhesion on Collagen under Flow in Mice Lacking the Atypical Rho GTPase RhoBTB3. Cells 2019; 8:E149. [PMID: 30754723 DOI: 10.3390/cells8020149] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/31/2019] [Accepted: 02/07/2019] [Indexed: 12/23/2022] Open
Abstract
Typical Rho GTPases, such as Rac1, Cdc42, and RhoA, act as molecular switches regulating various aspects of platelet cytoskeleton reorganization. The loss of these enzymes results in reduced platelet functionality. Atypical Rho GTPases of the RhoBTB subfamily are characterized by divergent domain architecture. One family member, RhoBTB3, is expressed in platelets, but its function is unclear. In the present study we examined the role of RhoBTB3 in platelet function using a knockout mouse model. We found the platelet count, size, numbers of both alpha and dense granules, and surface receptor profile in these mice were comparable to wild-type mice. Deletion of Rhobtb3 had no effect on aggregation and dense granule secretion in response to a range of agonists including thrombin, collagen, and adenosine diphosphate (ADP). By contrast, alpha-granule secretion increased in mice lacking RhoBTB3 in response to thrombin, collagen related peptide (CRP) and U46619/ADP. Integrin activation and spreading on fibrinogen and collagen under static conditions were also unimpaired; however, we observed reduced platelet accrual on collagen under flow conditions. These defects did not translate into alterations in tail bleeding time. We conclude that genetic deletion of Rhobtb3 leads to subtle alterations in alpha-granule secretion and adhesion to collagen without significant effects on hemostasis in vivo.
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Nwankwo JO, Gremmel T, Gerrits AJ, Mithila FJ, Warburton RR, Hill NS, Lu Y, Richey LJ, Jakubowski JA, Frelinger AL, Chishti AH. Calpain-1 regulates platelet function in a humanized mouse model of sickle cell disease. Thromb Res 2017; 160:58-65. [PMID: 29101791 DOI: 10.1016/j.thromres.2017.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/02/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022]
Abstract
One of the major contributors to sickle cell disease (SCD) pathobiology is the hemolysis of sickle red blood cells (RBCs), which release free hemoglobin and platelet agonists including adenosine 5'-diphosphate (ADP) into the plasma. While platelet activation/aggregation may promote tissue ischemia and pulmonary hypertension in SCD, modulation of sickle platelet dysfunction remains poorly understood. Calpain-1, a ubiquitous calcium-activated cysteine protease expressed in hematopoietic cells, mediates aggregation of platelets in healthy mice. We generated calpain-1 knockout Townes sickle (SSCKO) mice to investigate the role of calpain-1 in steady state and hypoxia/reoxygenation (H/R)-induced sickle platelet activation and aggregation, clot retraction, and pulmonary arterial hypertension. Using multi-electrode aggregometry, which measures platelet adhesion and aggregation in whole blood, we determined that steady state SSCKO mice exhibit significantly impaired PAR4-TRAP-stimulated platelet aggregation as compared to Townes sickle (SS) and humanized control (AA) mice. Interestingly, the H/R injury induced platelet hyperactivity in SS and SSCKO, but not AA mice, and partially rescued the aggregation defect in SSCKO mice. The PAR4-TRAP-stimulated GPIIb-IIIa (αIIbβ3) integrin activation was normal in SSCKO platelets suggesting that an alternate mechanism mediates the impaired platelet aggregation in steady state SSCKO mice. Taken together, we provide the first evidence that calpain-1 regulates platelet hyperactivity in sickle mice, and may offer a viable pharmacological target to reduce platelet hyperactivity in SCD.
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Affiliation(s)
- Jennifer O Nwankwo
- Graduate Program in Pharmacology and Experimental Therapeutics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Thomas Gremmel
- Center for Platelet Research Studies, Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Anja J Gerrits
- Center for Platelet Research Studies, Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Farha J Mithila
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, USA
| | - Rod R Warburton
- Division of Pulmonary, Critical Care and Sleep Medicine, Tufts Medical Center, Boston, MA, USA
| | - Nicholas S Hill
- Division of Pulmonary, Critical Care and Sleep Medicine, Tufts Medical Center, Boston, MA, USA
| | - Yunzhe Lu
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, USA
| | - Lauren J Richey
- Division of Laboratory Animal Medicine, Tufts University, Boston, MA, USA
| | | | - Andrew L Frelinger
- Center for Platelet Research Studies, Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Athar H Chishti
- Graduate Program in Pharmacology and Experimental Therapeutics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA; Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, USA.
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11
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Anderson R, Feldman C. Review manuscript: Mechanisms of platelet activation by the pneumococcus and the role of platelets in community-acquired pneumonia. J Infect 2017; 75:473-485. [PMID: 28943342 DOI: 10.1016/j.jinf.2017.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 12/11/2022]
Abstract
There is increasing recognition of the involvement of platelets in orchestrating inflammatory responses, driving the activation of neutrophils, monocytes and vascular endothelium, which, if poorly controlled, may lead to microvascular dysfunction. Importantly, hyperreactivity of platelets has been implicated in the pathogenesis of myocardial injury and the associated particularly high prevalence of acute cardiovascular events in patients with severe community-acquired pneumonia (CAP), of which Streptococcus pneumoniae (pneumococcus) is the most commonly encountered aetiologic agent. In this context, it is noteworthy that a number of studies have documented various mechanisms by which the pneumococcus may directly promote platelet aggregation and activation. The major contributors to platelet activation include several different types of pneumococcal adhesin, the pore-forming toxin, pneumolysin, and possibly pathogen-derived hydrogen peroxide, which collectively represent a major focus of the current review. This is followed by an overview of the limited experimental studies together with a larger series of clinical studies mainly focused on all-cause CAP, which have provided evidence in support of associations between alterations in circulating platelet counts, most commonly thrombocytopenia, and a poor clinical outcome. The final section of the review covers, albeit briefly, systemic biomarkers of platelet activation which may have prognostic potential.
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Affiliation(s)
- Ronald Anderson
- Department of Immunology and Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
| | - Charles Feldman
- Division of Pulmonology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Grundler K, Rotter R, Tilley S, Pircher J, Czermak T, Yakac M, Gaitzsch E, Massberg S, Krötz F, Sohn HY, Pohl U, Mannell H, Kraemer BF. The proteasome regulates collagen-induced platelet aggregation via nuclear-factor-kappa-B (NFĸB) activation. Thromb Res 2016; 148:15-22. [PMID: 27768934 DOI: 10.1016/j.thromres.2016.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/05/2016] [Accepted: 10/11/2016] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Platelets possess critical hemostatic functions in the system of thrombosis and hemostasis, which can be affected by a multitude of external factors. Previous research has shown that platelets have the capacity to synthesize proteins de novo and more recently a multicatalytic protein complex, the proteasome, has been discovered in platelets. Due to its vital function for cellular integrity, the proteasome has become a therapeutic target for anti-proliferative drug therapies in cancer. Clinically thrombocytopenia is a frequent side-effect, but the aggregatory function of platelets also appears to be affected. Little is known however about underlying regulatory mechanisms and functional aspects of proteasome inhibition on platelets. Our study aims to investigate the role of the proteasome in regulating collagen-induced platelet aggregation and its interaction with NFkB in this context. MATERIAL AND METHODS Using fluorescence activity assays, platelet aggregometry and immunoblotting, we investigate regulatory interactions of the proteasome and Nuclear-factor-kappa-B (NFkB) in collagen-induced platelet aggregation. RESULTS We show that collagen induces proteasome activation in platelets and collagen-induced platelet aggregation can be reduced with proteasome inhibition by the specific inhibitor epoxomicin. This effect does not depend on Rho-kinase/ROCK activation or thromboxane release, but rather depends on NFkB activation. Inhibition of the proteasome prevented cleavage of NFκB-inhibitor protein IκBα and decreased NFκB activity after collagen stimulation. Inhibition of the NFκB-pathway in return reduced collagen-induced platelet proteasome activity and cleavage of proteasome substrates. CONCLUSIONS This work offers novel explanations how the proteasome influences collagen-dependent platelet aggregation by involving non-genomic functions of NFkB.
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Affiliation(s)
- Katharina Grundler
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany; Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany
| | - Raffaela Rotter
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany
| | - Sloane Tilley
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany
| | - Joachim Pircher
- Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany
| | - Thomas Czermak
- Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany
| | - Mustaf Yakac
- Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany
| | - Erik Gaitzsch
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany; DZHK (German Center for Cardiovascular Research) partner site Munich Heart Alliance, Munich, Germany
| | - Florian Krötz
- Klinikum Starnberg, Osswaldstr.1, 82319 Starnberg, Germany
| | - Hae-Young Sohn
- MediCenter Germering, Hartstr. 52, 82110 Germering, Germany
| | - Ulrich Pohl
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany; DZHK (German Center for Cardiovascular Research) partner site Munich Heart Alliance, Munich, Germany
| | - Hanna Mannell
- Walter Brendel-Zentrum, Ludwig-Maximilians Universitaet Muenchen, Schillerstr. 44, 80336 Muenchen, Gemany
| | - Bjoern F Kraemer
- Medizinische Klinik und Poliklinik I, Klinikum der Universitaet Muenchen, Ziemssenstr. 1, 80336 Muenchen, Germany.
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13
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Koessler J, Etzel J, Weber K, Boeck M, Kobsar A. Evaluation of dose-dependent effects of the proteasome inhibitor bortezomib in human platelets. Eur J Pharmacol 2016; 791:99-104. [PMID: 27568836 DOI: 10.1016/j.ejphar.2016.08.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/25/2016] [Accepted: 08/25/2016] [Indexed: 01/06/2023]
Abstract
Platelets express key proteins of the proteasome system and contain protein ubiquitination pathways. The functional role of the proteasome system in platelets, however, is still subject of studies. In addition to its role as anticancer drug, the potent and selective proteasome inhibitor bortezomib can be used for experimental proteasome research. Since it is mandatory to know exact dose-effect relationships, we intended to evaluate dose-dependent specific bortezomib effects on basal and on agonist-induced proteasome activitiy, on levels of poly-ubiquitinated proteins and on platelet aggregation. In washed platelets, unstimulated or stimulated with different agonists and pre-incubated with various bortezomib concentrations, the proteasome activity was determined by a fluorometric assay. The levels of poly-ubiquitinated proteins were assessed by an immunoassay kit. Platelet aggregation was measured by light transmission aggregometry in platelet-rich-plasma. Platelet agonists stimulate both, the proteasome activity and the accumulation of poly-ubiquitinated proteins in platelets. Bortezomib inhibits the basal and the agonist induced proteasome activity and increased the content of poly-ubiquitinated proteins in a concentration dependent manner. Bortezomib concentrations in the nM-range causing complete blockade of platelet proteasome activity do not affect agonist induced platelet aggregation, indicating that the level of platelet proteasome activity is not directly linked with the induction of platelet aggregation. Bortezomib in the µM-range may tamper platelet aggregation, possibly due to unspecific and toxic effects.
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Affiliation(s)
- Juergen Koessler
- Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Straße 6, D-97080 Wuerzburg, Germany.
| | - Julia Etzel
- Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Straße 6, D-97080 Wuerzburg, Germany.
| | - Katja Weber
- Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Straße 6, D-97080 Wuerzburg, Germany.
| | - Markus Boeck
- Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Straße 6, D-97080 Wuerzburg, Germany.
| | - Anna Kobsar
- Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Straße 6, D-97080 Wuerzburg, Germany.
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14
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Gupta N, Li W, McIntyre TM. Deubiquitinases Modulate Platelet Proteome Ubiquitination, Aggregation, and Thrombosis. Arterioscler Thromb Vasc Biol 2015; 35:2657-66. [PMID: 26471267 DOI: 10.1161/atvbaha.115.306054] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/24/2015] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Platelets express a functional ubiquitin-proteasome system. Mass spectrometry shows that platelets contain several deubiquitinases, but whether these are functional, modulate the proteome, or affect platelet reactivity are unknown. APPROACH AND RESULTS Platelet lysates contained ubiquitin-protein deubiquitinase activity hydrolyzing both Lys48 and Lys63 polyubiquitin conjugates that was suppressed by the chemically unrelated deubiquitinase inhibitors PYR41 and PR619. These inhibitors acutely and markedly increased monoubiquitination and polyubiquitination of the proteome of resting platelets. PYR41 (intravenous, 15 minutes) significantly impaired occlusive thrombosis in FeCl3-damaged carotid arteries, and deubiquitinase inhibition reduced platelet adhesion and retention during high shear flow of whole blood through microfluidic chambers coated with collagen. Total internal reflection microscopy showed that adhesion and spreading in the absence of flow were strongly curtailed by these inhibitors with failure of stable process extension and reduced the retraction of formed clots. Deubiquitinase inhibition also sharply reduced homotypic platelet aggregation in response to not only the incomplete agonists ADP and collagen acting through glycoprotein VI but also to the complete agonist thrombin. Suppressed aggregation was accompanied by curtailed procaspase activating compound-1 binding to activated IIb/IIIa and inhibition of P-selectin translocation to the platelet surface. Deubiquitinase inhibition abolished the agonist-induced spike in intracellular calcium, suppressed Akt phosphorylation, and reduced agonist-stimulated phosphatase and tensin homolog phosphatase phosphorylation. Platelets express the proteasome-associated deubiquitinases USP14 and UCHL5, and selective inhibition of these enzymes by b-AP15 reproduced the inhibitory effect of the general deubiquitinase inhibitors on ex vivo platelet function. CONCLUSIONS Remodeling of the ubiquitinated platelet proteome by deubiquitinases promotes agonist-stimulated intracellular signal transduction and platelet responsiveness.
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Affiliation(s)
- Nilaksh Gupta
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH; and Department of Molecular Medicine, Case Western Reserve University, Cleveland, OH
| | - Wei Li
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH; and Department of Molecular Medicine, Case Western Reserve University, Cleveland, OH
| | - Thomas M McIntyre
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH; and Department of Molecular Medicine, Case Western Reserve University, Cleveland, OH.
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15
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Ouseph MM, Huang Y, Banerjee M, Joshi S, MacDonald L, Zhong Y, Liu H, Li X, Xiang B, Zhang G, Komatsu M, Yue Z, Li Z, Storrie B, Whiteheart SW, Wang QJ. Autophagy is induced upon platelet activation and is essential for hemostasis and thrombosis. Blood 2015; 126:1224-33. [PMID: 26209658 DOI: 10.1182/blood-2014-09-598722] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Autophagy is important for maintaining cellular homeostasis, and thus its deficiency is implicated in a broad spectrum of human diseases. Its role in platelet function has only recently been examined. Our biochemical and imaging studies demonstrate that the core autophagy machinery exists in platelets, and that autophagy is constitutively active in resting platelets. Moreover, autophagy is induced upon platelet activation, as indicated by agonist-induced loss of the autophagy marker LC3II. Additional experiments, using inhibitors of platelet activation, proteases, and lysosomal acidification, as well as platelets from knockout mouse strains, show that agonist-induced LC3II loss is a consequence of platelet signaling cascades and requires proteases, acidic compartments, and membrane fusion. To assess the physiological role of platelet autophagy, we generated a mouse strain with a megakaryocyte- and platelet-specific deletion of Atg7, an enzyme required for LC3II production. Ex vivo analysis of platelets from these mice shows modest defects in aggregation and granule cargo packaging. Although these mice have normal platelet numbers and size distributions, they exhibit a robust bleeding diathesis in the tail-bleeding assay and a prolonged occlusion time in the FeCl3-induced carotid injury model. Our results demonstrate that autophagy occurs in platelets and is important for hemostasis and thrombosis.
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16
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Liao CY, Lee CL, Wang HC, Liang SS, Kung PH, Wu YC, Chang FR, Wu CC. CLL2-1, a chemical derivative of orchid 1,4-phenanthrenequinones, inhibits human platelet aggregation through thiol modification of calcium-diacylglycerol guanine nucleotide exchange factor-I (CalDAG-GEFI). Free Radic Biol Med 2015; 78:101-10. [PMID: 25451646 DOI: 10.1016/j.freeradbiomed.2014.10.512] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 10/14/2014] [Accepted: 10/14/2014] [Indexed: 11/29/2022]
Abstract
CalDAG-GEFI is a guanine nucleotide exchange factor, which actives small GTPase Rap1 and plays an important role in platelet aggregation. Our previous study has shown that CalDAG-GEFI contains redox-sensitive thiols, and its function can be inhibited by thiol modification. In the present study, the effect of CLL2-1, a 1,4-phenanthrenequinone, on CalDAG-GEFI and platelet functions was investigated. In human platelets, CLL2-1 prevented platelet aggregation caused by various stimulators. Flow cytometric analysis revealed that CLL2-1 inhibited GPIIb/IIIa activation and P-selectin secretion. Moreover, CLL2-1 prevented Rap1 activation caused by thrombin, the Ca(2+) ionophore A23187, and the diacylglycerol mimetic phorbol 12-myristate 13-acetate, while only slightly inhibited thrombin-induced increases in [Ca(2+)]i and did not inhibit protein kinase C activation. Western blots after reducing SDS-PAGE showed that treatment of either platelets or platelet lysates with CLL2-1 led to a decrease of monomeric CalDAG-GEFI and appearance of cross-linked oligomers of CalDAG-GEFI, and these effects were inhibited by pretreatment of platelets or lysates with thiol reducing agents prior to the addition of CLL2-1, indicating thiol modification of CalDAG-GEFI by CLL2-1. Furthermore, the thiol reducing agents also prevented the inhibitory effect of CLL2-1 on Rap1 activation, GPIIb/IIIa activation, and platelet aggregation. In CalDAG-GEFI-overexpressing human embryonic kidney 293T cells, CLL2-1 also inhibited CalDAG-GEFI-mediated Rap1 activation. Taken together, our results suggest that the antiplatelet effect of CLL2-1 is due to, at least in part, inhibition of CalDAG-GEFI-mediated Rap1 activation, and provide the basis for development of novel antiplatelet drugs.
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Affiliation(s)
- Chieh-Yu Liao
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chia-Lin Lee
- School of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Hui-Chun Wang
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shih-Shin Liang
- Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Po-Hsiung Kung
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yang-Chang Wu
- School of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Fang-Rong Chang
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chin-Chung Wu
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.
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17
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Shi DS, Smith MCP, Campbell RA, Zimmerman PW, Franks ZB, Kraemer BF, Machlus KR, Ling J, Kamba P, Schwertz H, Rowley JW, Miles RR, Liu ZJ, Sola-Visner M, Italiano JE, Christensen H, Kahr WHA, Li DY, Weyrich AS. Proteasome function is required for platelet production. J Clin Invest 2014; 124:3757-66. [PMID: 25061876 DOI: 10.1172/jci75247] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 06/05/2014] [Indexed: 01/03/2023] Open
Abstract
The proteasome inhibiter bortezomib has been successfully used to treat patients with relapsed multiple myeloma; however, many of these patients become thrombocytopenic, and it is not clear how the proteasome influences platelet production. Here we determined that pharmacologic inhibition of proteasome activity blocks proplatelet formation in human and mouse megakaryocytes. We also found that megakaryocytes isolated from mice deficient for PSMC1, an essential subunit of the 26S proteasome, fail to produce proplatelets. Consistent with decreased proplatelet formation, mice lacking PSMC1 in platelets (Psmc1(fl/fl) Pf4-Cre mice) exhibited severe thrombocytopenia and died shortly after birth. The failure to produce proplatelets in proteasome-inhibited megakaryocytes was due to upregulation and hyperactivation of the small GTPase, RhoA, rather than NF-κB, as has been previously suggested. Inhibition of RhoA or its downstream target, Rho-associated protein kinase (ROCK), restored megakaryocyte proplatelet formation in the setting of proteasome inhibition in vitro. Similarly, fasudil, a ROCK inhibitor used clinically to treat cerebral vasospasm, restored platelet counts in adult mice that were made thrombocytopenic by tamoxifen-induced suppression of proteasome activity in megakaryocytes and platelets (Psmc1(fl/fl) Pdgf-Cre-ER mice). These results indicate that proteasome function is critical for thrombopoiesis, and suggest inhibition of RhoA signaling as a potential strategy to treat thrombocytopenia in bortezomib-treated multiple myeloma patients.
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18
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Liu ZJ, Hoffmeister KM, Hu Z, Mager DE, Ait-Oudhia S, Debrincat MA, Pleines I, Josefsson EC, Kile BT, Italiano J Jr, Ramsey H, Grozovsky R, Veng-Pedersen P, Chavda C, Sola-Visner M. Expansion of the neonatal platelet mass is achieved via an extension of platelet lifespan. Blood 2014; 123:3381-9. [PMID: 24599546 DOI: 10.1182/blood-2013-06-508200] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The fetal/neonatal hematopoietic system must generate enough blood cells to meet the demands of rapid growth. This unique challenge might underlie the high incidence of thrombocytopenia among preterm neonates. In this study, neonatal platelet production and turnover were investigated in newborn mice. Based on a combination of blood volume expansion and increasing platelet counts, the platelet mass increased sevenfold during the first 2 weeks of murine life, a time during which thrombopoiesis shifted from liver to bone marrow. Studies applying in vivo biotinylation and mathematical modeling showed that newborn and adult mice had similar platelet production rates, but neonatal platelets survived 1 day longer in circulation. This prolonged lifespan fully accounted for the rise in platelet counts observed during the second week of murine postnatal life. A study of pro-apoptotic and anti-apoptotic Bcl-2 family proteins showed that neonatal platelets had higher levels of the anti-apoptotic protein Bcl-2 and were more resistant to apoptosis induced by the Bcl-2/Bcl-xL inhibitor ABT-737 than adult platelets. However, genetic ablation or pharmacologic inhibition of Bcl-2 alone did not shorten neonatal platelet survival or reduce platelet counts in newborn mice, indicating the existence of redundant or alternative mechanisms mediating the prolonged lifespan of neonatal platelets.
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19
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Affiliation(s)
- H F Langer
- Harald F. Langer, MD, Department of Cardiology and Cardiovascular Medicine, University Clinic of Tuebingen, Ottfried-Müller-Str. 10, 72076 Tuebingen, Germany, E-mail:
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