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Gremmel T, Frelinger AL, Michelson AD. Platelet Physiology. Semin Thromb Hemost 2024. [PMID: 38653463 DOI: 10.1055/s-0044-1786387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Platelets are the smallest blood cells, numbering 150 to 350 × 109/L in healthy individuals. The ability of activated platelets to adhere to an injured vessel wall and form aggregates was first described in the 19th century. Besides their long-established roles in thrombosis and hemostasis, platelets are increasingly recognized as pivotal players in numerous other pathophysiological processes including inflammation and atherogenesis, antimicrobial host defense, and tumor growth and metastasis. Consequently, profound knowledge of platelet structure and function is becoming more important in research and in many fields of modern medicine. This review provides an overview of platelet physiology focusing particularly on the structure, granules, surface glycoproteins, and activation pathways of platelets.
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Affiliation(s)
- Thomas Gremmel
- Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
- Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria
- Institute of Cardiovascular Pharmacotherapy and Interventional Cardiology, Karl Landsteiner Society, St. Pölten, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
- Department of Internal Medicine I, Cardiology and Intensive Care Medicine, Landesklinikum Mistelbach-Gänserndorf, Mistelbach, Austria
| | - Andrew L Frelinger
- Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Alan D Michelson
- Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
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2
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Trotta A, Milillo MA, Serafino A, Castillo LA, Birnberg Weiss F, Delpino MV, Giambartolomei GH, Fernández GC, Barrionuevo P. Brucella abortus-infected platelets modulate the activation of neutrophils. Immunol Cell Biol 2020; 98:743-756. [PMID: 32623755 DOI: 10.1111/imcb.12373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 01/18/2023]
Abstract
Brucellosis is a contagious disease caused by bacteria of the genus Brucella. Platelets (PLTs) have been widely involved in the modulation of the immune response. We have previously reported the modulation of Brucella abortus-mediated infection of monocytes. As a result, PLTs cooperate with monocytes and increase their inflammatory capacity, promoting the resolution of the infection. Extending these results, in this study we demonstrate that patients with brucellosis present slightly elevated levels of complexes between PLTs and both monocytes and neutrophils. We then assessed whether PLTs were capable of modulating functional aspects of neutrophils. The presence of PLTs throughout neutrophil infection increased the production of interleukin-8, CD11b surface expression and reactive oxygen species formation, whereas it decreased the expression of CD62L, indicating an activated status of these cells. We next analyzed whether this modulation was mediated by released factors. To discriminate between these options, neutrophils were treated with supernatants collected from B. abortus-infected PLTs. Our results show that CD11b expression was induced by soluble factors of PLTs but direct contact between cell populations was needed to enhance the respiratory burst. Additionally, B. abortus-infected PLTs recruit polymorphonuclear (PMN) cells to the site of infection. Finally, the presence of PLTs did not modify the initial invasion of PMN cells by B. abortus but improved the control of the infection at extended times. Altogether, our results demonstrate that PLTs interact with neutrophils and promote a proinflammatory phenotype which could also contribute to the resolution of the infection.
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Affiliation(s)
- Aldana Trotta
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - M Ayelén Milillo
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Agustina Serafino
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Luis A Castillo
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Federico Birnberg Weiss
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - M Victoria Delpino
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), CONICET, Buenos Aires, Argentina
| | | | - Gabriela C Fernández
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Paula Barrionuevo
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
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3
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1,3-Dipolar cycloaddition reaction on carbohydrate template: Stereoselective synthesis of glycospiroheterocycles. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Platelet and Red Blood Cell Counts, as well as the Concentrations of Uric Acid, but Not Homocysteinaemia or Oxidative Stress, Contribute Mostly to Platelet Reactivity in Older Adults. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:9467562. [PMID: 30800213 PMCID: PMC6360040 DOI: 10.1155/2019/9467562] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 12/02/2018] [Indexed: 12/15/2022]
Abstract
Purpose The goal of this study was to estimate the hierarchical contribution of the most commonly recognized cardiovascular risk factors associated with atherogenesis to activation and reactivity of blood platelets in a group of men and women at ages 60-65. Methods Socioeconomic and anthropometric data were taken from questionnaires. Blood morphology and biochemistry were measured with standard diagnostic methods. Plasma serum homocysteine was measured by immunochemical method. Plasma concentrations of VCAM, ICAM, total antioxidant status, and total oxidant status were estimated with commercial ELISA kits. Markers of oxidative stress of plasma and platelet proteins (concentrations of protein free thiol and amino groups) and lipids (concentrations of lipid peroxides) and generation of superoxide anion by platelets were measured with colorimetric methods. Platelet reactivity was estimated by impedance aggregometry with arachidonate, collagen, and ADP as agonists. Expression of selectin-P and GPIIb/IIIa on blood platelets was tested by flow cytometry. Results Platelet aggregation associated significantly negatively with HGB and age and significantly positively with PLT, MPV, PCT, PDW, and P-LCR. When platelet reactivity (“cumulative platelet reactivity_aggregation”) was analyzed in a cumulated manner, the negative association with serum concentration of uric acid (Rs = −0.169, p = 0.003) was confirmed. Multivariate analysis revealed that amongst blood morphological parameters, platelet count, plateletcrit, and number of large platelets and uric acid are the most predictive variables for platelet reactivity. Conclusions The most significant contributors to platelet reactivity in older subjects are platelet morphology, plasma uricaemia, and erythrocyte morphology.
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6
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Rossaint J, Margraf A, Zarbock A. Role of Platelets in Leukocyte Recruitment and Resolution of Inflammation. Front Immunol 2018; 9:2712. [PMID: 30515177 PMCID: PMC6255980 DOI: 10.3389/fimmu.2018.02712] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/02/2018] [Indexed: 12/30/2022] Open
Abstract
Platelets are most often recognized for their crucial role in the control of acute hemorrhage. However, current research has greatly expanded the appreciation of platelets beyond their contribution to primary hemostasis, indicating that platelets also actively participate in leukocyte recruitment and the regulation of the host defense in response to exogenous pathogens and sterile injury. Early recruitment of leukocytes, especially neutrophils, is the evolutionary stronghold of the innate immune response to successfully control exogenous infections. Platelets have been shown to physically interact with different leukocyte subsets during inflammatory processes. This interaction holds far-reaching implications for the leukocyte recruitment into peripheral tissues as well as the regulation of leukocyte cell autonomous functions, including the formation and liberation of neutrophil extracellular traps. These functions critically depend on the interaction of platelets with leukocytes. The host immune response and leukocyte recruitment must be tightly regulated to avoid excessive tissue and organ damage and to avoid chronification of inflammation. Thus, platelet-leukocyte interactions and the resulting leukocyte activation and recruitment also underlies tight regulation by several inherited feedback mechanisms to limit the extend of vascular inflammation and to protect the host from collateral damage caused by overshooting immune system activation. After the acute inflammatory phase has been overcome the host defense response must eventually be terminated to allow for resolution from inflammation and restoration of tissue and organ function. Besides their essential role for leukocyte recruitment and the initiation and propagation of vascular inflammation, platelets have lately also been implicated in the resolution process. Here, their contribution to phagocyte clearance, T cell recruitment and macrophage reprogramming is also of outmost importance. This review will focus on the role of platelets in leukocyte recruitment during the initiation of the host defense and we will also discuss the participation of platelets in the resolution process after acute inflammation.
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Affiliation(s)
- Jan Rossaint
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Andreas Margraf
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany.,Interdisciplinary Centre for Clinical Research, University Hospital Münster, Münster, Germany
| | - Alexander Zarbock
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
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7
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Platelet communication with the vascular wall: role of platelet-derived microparticles and non-coding RNAs. Clin Sci (Lond) 2018; 132:1875-1888. [PMID: 30185611 DOI: 10.1042/cs20180580] [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: 07/02/2018] [Revised: 07/31/2018] [Accepted: 08/09/2018] [Indexed: 12/24/2022]
Abstract
Platelets play an important role in vascular homeostasis through their interaction with circulating blood cells as well as the vascular wall. Platelet-mediated communication with other cells can take the form of direct cell-cell interactions via membrane receptors or indirectly through the release of different soluble factors stored in their granules as well as through the release of microparticles. The latter carry different proteins and RNAs which are transferred to the target cells. The aim of this review is to discuss the role of platelet-derived factors, adhesion molecules as well as RNAs as mediators of the cross-talk between platelets and the vessel wall.
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8
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Deppermann C, Kubes P. Start a fire, kill the bug: The role of platelets in inflammation and infection. Innate Immun 2018; 24:335-348. [PMID: 30049243 PMCID: PMC6830908 DOI: 10.1177/1753425918789255] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/16/2018] [Accepted: 06/26/2018] [Indexed: 11/19/2022] Open
Abstract
Platelets are the main players in thrombosis and hemostasis; however they also play important roles during inflammation and infection. Through their surface receptors, platelets can directly interact with pathogens and immune cells. Platelets form complexes with neutrophils to modulate their capacities to produce reactive oxygen species or form neutrophil extracellular traps. Furthermore, they release microbicidal factors and cytokines that kill pathogens and influence the immune response, respectively. Platelets also maintain the vascular integrity during inflammation by a mechanism that is different from classical platelet activation. In this review we summarize the current knowledge about how platelets interact with the innate immune system during inflammation and infection and highlight recent advances in the field.
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Affiliation(s)
- Carsten Deppermann
- Calvin, Phoebe and Joan Snyder Institute for Chronic
Diseases, University of Calgary, Calgary, AB, Canada
| | - Paul Kubes
- Calvin, Phoebe and Joan Snyder Institute for Chronic
Diseases, University of Calgary, Calgary, AB, Canada
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9
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Danesh A, Inglis HC, Abdel-Mohsen M, Deng X, Adelman A, Schechtman KB, Heitman JW, Vilardi R, Shah A, Keating SM, Cohen MJ, Jacobs ES, Pillai SK, Lacroix J, Spinella PC, Norris PJ. Granulocyte-Derived Extracellular Vesicles Activate Monocytes and Are Associated With Mortality in Intensive Care Unit Patients. Front Immunol 2018; 9:956. [PMID: 29867942 PMCID: PMC5951932 DOI: 10.3389/fimmu.2018.00956] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/17/2018] [Indexed: 11/13/2022] Open
Abstract
To understand how extracellular vesicle (EV) subtypes differentially activate monocytes, a series of in vitro studies were performed. We found that plasma-EVs biased monocytes toward an M1 profile. Culturing monocytes with granulocyte-, monocyte-, and endothelial-EVs induced several pro-inflammatory cytokines. By contrast, platelet-EVs induced TGF-β and GM-CSF, and red blood cell (RBC)-EVs did not activate monocytes in vitro. The scavenger receptor CD36 was important for binding of RBC-EVs to monocytes, while blockade of CD36, CD163, CD206, TLR1, TLR2, and TLR4 did not affect binding of plasma-EVs to monocytes in vitro. To identify mortality risk factors, multiple soluble factors and EV subtypes were measured in patients' plasma at intensive care unit admission. Of 43 coagulation factors and cytokines measured, two were significantly associated with mortality, tissue plasminogen activator and cystatin C. Of 14 cellular markers quantified on EVs, 4 were early predictors of mortality, including the granulocyte marker CD66b. In conclusion, granulocyte-EVs have potent pro-inflammatory effects on monocytes in vitro. Furthermore, correlation of early granulocyte-EV levels with mortality in critically ill patients provides a potential target for intervention in management of the pro-inflammatory cascade associated with critical illness.
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Affiliation(s)
- Ali Danesh
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Heather C Inglis
- Blood Systems Research Institute, San Francisco, CA, United States
| | - Mohamed Abdel-Mohsen
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Xutao Deng
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Avril Adelman
- Division of Biostatistics, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Kenneth B Schechtman
- Division of Biostatistics, Washington University School of Medicine in St. Louis, St. Louis, MO, United States.,Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - John W Heitman
- Blood Systems Research Institute, San Francisco, CA, United States
| | - Ryan Vilardi
- Department of Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Avani Shah
- Blood Systems Research Institute, San Francisco, CA, United States
| | - Sheila M Keating
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Mitchell J Cohen
- Department of Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Evan S Jacobs
- Blood Systems Research Institute, San Francisco, CA, United States
| | - Satish K Pillai
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Jacques Lacroix
- Centre Hospitalier Universitaire (CHU) Sainte-Justine, Université de Montréal, Montreal, QC, Canada
| | - Philip C Spinella
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Philip J Norris
- Blood Systems Research Institute, San Francisco, CA, United States.,Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States.,Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
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10
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Li N. CD4+ T cells in atherosclerosis: Regulation by platelets. Thromb Haemost 2017; 109:980-90. [DOI: 10.1160/th12-11-0819] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 01/28/2013] [Indexed: 02/06/2023]
Abstract
SummaryAtherosclerosis is an inflammatory and thrombotic disease, in which both CD4+ T cells and platelets play important roles throughout all stages of atherogenesis. CD4+ T cells are the most abundant T cells present in atherosclerotic lesions. They are primarily seen as type 1 T helper (Th1) cells, while the other CD4+ T cell subsets Th2, Th17, and regulatory T (Treg) cells are also found in the lesions with lower frequencies. CD4+ T effector cells release various cytokines, which exert paracrine or autocrine effects among different CD4+ T cell subsets and other lesional cells and subsequently modulate inflammatory processes in the lesions. Platelets are instrumental in thrombosis and haemostasis, but also play important regulatory roles in immune response, inflammation, and angiogenesis. The present review summarises the current knowledge and/or understanding on how platelets regulate recruitment, activation, differentiation, and cytokine production of different CD4+ T cell subsets, as well as impacts of the platelet-CD4+ T cell interactions on atherogenesis. The research perspectives of platelet-CD4+ T cell interaction in atherosclerosis are also discussed.
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11
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Zamora C, Cantó E, Nieto JC, Bardina J, Diaz-Torné C, Moya P, Magallares B, Ortiz MA, Julià G, Juarez C, Llobet JM, Vidal S. Binding of Platelets to Lymphocytes: A Potential Anti-Inflammatory Therapy in Rheumatoid Arthritis. THE JOURNAL OF IMMUNOLOGY 2017; 198:3099-3108. [PMID: 28250158 DOI: 10.4049/jimmunol.1601708] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/03/2017] [Indexed: 12/15/2022]
Abstract
Soluble factors released from platelets can modulate the immune response of leukocytes. We and others have recently found that T lymphocytes with bound platelets have reduced proliferation and IFN-γ and IL-17 production. Thus, we speculate that if we induce the binding of platelets to lymphocytes, we will be able to regulate the inflammatory response. When we cocultured platelets with lymphocytes at different ratios, we were able to increase the percentage of lymphocytes with bound platelets. The coculture of platelets with lymphocytes in the presence of stimulation decreased the production of IFN-γ and TNF-α, T cell proliferation, and the expression of CD25, PD-L1, and SLAM. However, this coculture increased CD39 expression. All of these effects were dependent on the dose of platelets and operated indistinctly with platelets from different healthy donors. When platelets were cocultured in the same compartment with lymphocytes, we observed less IFN-γ and TNF-α production and T lymphocyte proliferation than in cultures with platelets separated from lymphocytes by a 0.4-μm pore size filter. The binding of platelets to lymphocytes was blocked with anti-P-selectin Abs, and when this occurred we observed higher IFN-γ and TNF-α production than in nonblocked conditions. The cocultures of platelets with synovial fluid cells from rheumatoid arthritis patients reduced inflammatory cytokine production and increased IL-10 production. These results suggest that platelet binding to lymphocytes effectively regulates T lymphocyte function. This mechanism could be easily applied to reduce inflammatory responses.
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Affiliation(s)
- Carlos Zamora
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain;
| | - Elisabet Cantó
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Juan C Nieto
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Jorge Bardina
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Cesar Diaz-Torné
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain.,Unitat Reumatologia, Hospital de la Santa Creu i Sant Pau, 08026 Barcelona, Spain; and
| | - Patricia Moya
- Unitat Reumatologia, Hospital de la Santa Creu i Sant Pau, 08026 Barcelona, Spain; and
| | - Berta Magallares
- Unitat Reumatologia, Hospital de la Santa Creu i Sant Pau, 08026 Barcelona, Spain; and
| | - M Angels Ortiz
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Germà Julià
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Candido Juarez
- Departament Immunologia, Hospital de la Santa Creu i Sant Pau, 08026 Barcelona, Spain
| | - Josep M Llobet
- Unitat Reumatologia, Hospital de la Santa Creu i Sant Pau, 08026 Barcelona, Spain; and
| | - Silvia Vidal
- Departament Immunologia, Institut Recerca Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain;
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Wang X, He Z, Liu H, Yousefi S, Simon HU. Neutrophil Necroptosis Is Triggered by Ligation of Adhesion Molecules following GM-CSF Priming. THE JOURNAL OF IMMUNOLOGY 2016; 197:4090-4100. [DOI: 10.4049/jimmunol.1600051] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 09/12/2016] [Indexed: 01/08/2023]
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Olsson AK, Cedervall J. NETosis in Cancer - Platelet-Neutrophil Crosstalk Promotes Tumor-Associated Pathology. Front Immunol 2016; 7:373. [PMID: 27708646 PMCID: PMC5030622 DOI: 10.3389/fimmu.2016.00373] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 09/07/2016] [Indexed: 01/13/2023] Open
Abstract
It has become increasingly clear that circulating immune cells in the body have a major impact on cancer development, progression, and outcome. The role of both platelets and neutrophils as independent regulators of various processes in cancer has been known for long, but it has quite recently emerged that the platelet-neutrophil interplay is yet a critical component to take into account during malignant disease. It was reported a few years ago that neutrophils in mice with cancer have increased propensity to form neutrophil extracellular traps (NETs) - web-like structures formed by externalized chromatin and secreted proteases. The initial finding describing this as a cell death-associated process has been followed by reports of additional mechanisms for NET formation (NETosis), and it has been shown that similar structures can be formed also without lysis and neutrophil cell death as a consequence. Furthermore, presence of NETs in humans with cancer has been verified in a few recent studies, indicating that tumor-induced NETosis is clinically relevant. Several reports have also described that NETs contribute to cancer-associated pathology, by promoting processes responsible for cancer-related death such as thrombosis, systemic inflammation, and relapse of the disease. This review summarizes current knowledge about NETosis in cancer, including the role of platelets as regulators of tumor-induced NETosis. It has been shown that platelets can serve as inducers of NETosis, and the platelet-neutrophil interface can therefore be an important issue to consider when designing therapies targeting cancer-associated pathology in the future.
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Affiliation(s)
- Anna-Karin Olsson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University , Uppsala , Sweden
| | - Jessica Cedervall
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University , Uppsala , Sweden
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Targeting of Neutrophil Lewis X Blocks Transepithelial Migration and Increases Phagocytosis and Degranulation. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:297-311. [PMID: 26687991 DOI: 10.1016/j.ajpath.2015.10.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/28/2015] [Accepted: 10/02/2015] [Indexed: 12/21/2022]
Abstract
Polymorphonuclear leukocytes (PMNs) are innate immune cells whose principal function is to migrate from the blood to sites of inflammation, where they exert crucial anti-infectious and immunomodulatory effects. However, dysregulated migration of PMNs into mucosal epithelial tissues is characteristic of chronic inflammatory disorders, including inflammatory bowel disease. Carbohydrate-mediated binding interactions between PMN Lewis glycans and endothelial glycan-binding proteins are critical for initial migration of PMN out of the vasculature. However, the role of Lewis glycans during transepithelial migration (TEM) has not been well characterized. Herein, we show that antibody blockade of Lewis X (Le(x)) displayed as terminal glycan residues on the PMN surface blocks chemotaxis and TEM while enhancing PMN-adhesive interactions with intestinal epithelia. Unexpectedly, targeting of subterminal Le(x) residues within glycan chains had no effect on PMN migration or adhesive interactions. There was increased surface expression of Le(x) on PMN after TEM, and blockade of terminal Le(x) regulated post-migratory PMN functions, increasing PMN phagocytosis and the surface mobilization of azurophilic (CD63, myeloperoxidase, and neutrophil elastase) and specific (CD66b and lactoferrin) granule markers. These findings suggest that terminal Le(x) represents a potential target for regulating PMN trafficking and function in inflamed mucosa. Furthermore, given its abundant expression on migrating PMN, Le(x) may be a rational target for modulating inflammation in diseases where dysregulated PMN influx is associated with host tissue damage.
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15
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The role of endothelial cell adhesion molecules in the development of atherosclerosis. Cardiovasc Pathol 2015; 1:17-28. [PMID: 25990035 DOI: 10.1016/1054-8807(92)90005-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/1991] [Accepted: 07/17/1991] [Indexed: 01/10/2023] Open
Abstract
The vascular endothelium serves as a dynamic interface between circulating blood elements and the interstitial tissues. As such, it communicates to cells within the vessel wall as well as to the surrounding tissue, sensing its environment and responding accordingly. The vasculature must maintain a delicate balance when initiating a functional response by producing both proinflammatory and antiinflammatory mediators, vasoconstrictors and vasodilators, growth stimulators and inhibitors, and prothrombogenic and antithrombogenic factors. Any response to injurious agents could lead to pathology. Confounding this complex interplay is the fact that the very response to injury that may have developed to undo the damage may itself be even more deleterious. One response to injury by the endothelium is the new or increased expression of surface receptors for immune elements. In atherosclerosis, the adhesion of monocytes (and T cells) to the endothelium is a key event triggered by some form of insult. Subsequent events include monocytic infiltration of the vessel wall, alterations in lipid metabolism, and the activation of these cells into foam cells. The presence of large numbers of foam cells in the intima may produce a high concentration of cytokines and growth factors within a localized area, extracellular matrix perturbations, smooth muscle cell proliferation, and ultimately platelet aggregation at the site of stenosis. Endothelial cells themselves will not only elaborate factors after the initial injury to the vessel wall but also in response to the factors produced by foam cells within the plaque. These endothelial cell factors include MCP-1, a chemoattractant for monocytes (179,180), IL-1 (63,64), IL-6 (interleukin-6) (65-67), IL-8 (interleukin 8) (181), and PDGF, a potent smooth muscle mitogen (4,72) (Fig. 3). Endothelial cells will propagate an inflammatory response long after the initial insult to the arterial vessel. A chronic cycle of endothelial cell activation and leukocyte infiltration is constitutively activated. Thus, all of the cellular elements of the vessel wall, as well as the atherosclerotic plaque itself, elaborate cytokines and growth factors that amplify and propagate the pathological process.
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16
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Amano H, Ito Y, Eshima K, Kato S, Ogawa F, Hosono K, Oba K, Tamaki H, Sakagami H, Shibuya M, Narumiya S, Majima M. Thromboxane A2induces blood flow recovery via platelet adhesion to ischaemic regions. Cardiovasc Res 2015; 107:509-21. [DOI: 10.1093/cvr/cvv139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 04/26/2015] [Indexed: 11/14/2022] Open
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Rossaint J, Zarbock A. Platelets in leucocyte recruitment and function. Cardiovasc Res 2015; 107:386-95. [PMID: 25712962 DOI: 10.1093/cvr/cvv048] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/08/2015] [Indexed: 11/14/2022] Open
Abstract
Platelets have a longstanding recognition as an essential cellular component of the coagulation system. However, substantial research over the last decade has added another important aspect to platelet function in that they are also an integral part of the innate immune system. Complex organisms are facing a constant threat of infections by invading pathogens, and they have developed a sophisticated and elegant measure to combat this threat, namely the immune system. Leucocyte recruitment to sites of infections is an essential step at the forefront of the immune response. Platelets have been shown to be involved in several steps of this process and they are an integrated connecting element among haemostasis, host defence, and additional immunological functions (e.g. neutrophil extracellular traps formation). However, the immune system also requires a tight regulation, as an overshooting immune response carries the risk of harming the host itself. This review aims at highlighting the unique features and molecular mechanisms that allow for the interactions of platelets and leucocytes and the regulation of this process. Furthermore, this article identifies the functional relevance of these events for the immune response.
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Affiliation(s)
- Jan Rossaint
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Alexander Zarbock
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany Max Planck Institute for Molecular Biomedicine, Münster, Germany
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Abstract
Despite their small size and anucleate status, platelets have diverse roles in vascular biology. Not only are platelets the cellular mediator of thrombosis, but platelets are also immune cells that initiate and accelerate many vascular inflammatory conditions. Platelets are linked to the pathogenesis of inflammatory diseases such as atherosclerosis, malaria infection, transplant rejection, and rheumatoid arthritis. In some contexts, platelet immune functions are protective, whereas in others platelets contribute to adverse inflammatory outcomes. In this review, we will discuss platelet and platelet-derived mediator interactions with the innate and acquired arms of the immune system and platelet-vessel wall interactions that drive inflammatory disease. There have been many recent publications indicating both important protective and adverse roles for platelets in infectious disease. Because of this new accumulating data, and the fact that infectious disease continues to be a leading cause of death globally, we will also focus on new and emerging concepts related to platelet immune and inflammatory functions in the context of infectious disease.
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Crossing the wall: The opening of endothelial cell junctions during infectious diseases. Int J Biochem Cell Biol 2013; 45:1165-73. [DOI: 10.1016/j.biocel.2013.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 03/05/2013] [Accepted: 03/15/2013] [Indexed: 12/22/2022]
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Page C, Pitchford S. Neutrophil and platelet complexes and their relevance to neutrophil recruitment and activation. Int Immunopharmacol 2013; 17:1176-84. [PMID: 23810443 DOI: 10.1016/j.intimp.2013.06.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 09/20/2012] [Accepted: 06/09/2013] [Indexed: 12/29/2022]
Abstract
The manifestation of platelet 'satallitism' around neutrophils in whole blood is a long acknowledged phenomenon [1]. Circulating platelet-neutrophil complexes (PNC) occur in a diverse range of inflammatory disorders and infections that affect numerous organs of the body. Animal models have revealed that the formation of PNC is required for the recruitment of neutrophils to inflamed tissue, since platelets 'prime' neutrophils for efficient adhesion to vascular endothelium via the up-regulation of integrins and enhanced responsiveness to chemokines (Fig. 1). Perhaps surprisingly, the surface contact between platelets and neutrophils additionally enhances other neutrophil functions, such as chemotaxis that is required for migration into tissues, trans-cellular production of eicosanoids, phagocytosis and trapping of pathogens, increased respiratory burst leading to the production of reactive oxygen species (ROS), and modulation of neutrophil apoptosis (Fig. 1). Platelet P-selectin appears to have a particular role in enhancing the majority of these activities, and the influence of platelet P-selectin is not therefore confined to the initial rolling events in the process of neutrophil extravasation.
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Affiliation(s)
- Clive Page
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, Kings College London, London SE1 9NH, UK
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A humanized single-chain antibody against beta 3 integrin inhibits pulmonary metastasis by preferentially fragmenting activated platelets in the tumor microenvironment. Blood 2012; 120:2889-98. [PMID: 22879538 DOI: 10.1182/blood-2012-04-425207] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Platelets play a supportive role in tumor metastasis. Impairment of platelet function within the tumor microenvironment may provide a clinically useful approach to inhibit metastasis. We developed a novel humanized single-chain antibody (scFv Ab) against integrin GPIIIa49-66 (named A11) capable of lysing activated platelets. In this study, we investigate the effect of A11 on the development of pulmonary metastases. In the Lewis lung carcinoma (LLC) metastatic model, A11 decreases the mean number of surface nodules and mean volume of pulmonary nodules. It protects against lung metastases in a time window that extended 4 hours before and 4 hours after the IV injection of LLCs. Coinjection of GPIIIa49-66 albumin reverses the antimetastatic activity of A11 in the B16 melanoma model, consistent with the pathophysiologic relevance of the platelet GPIIIa49-66 epitope. Significantly, A11 had no effect on angiogenesis using both in vitro and in vivo assays. The underlying molecular mechanisms are a combination of inhibition of each of the following interactions: between activated platelets and tumor cells, platelets and endothelial cells, and platelets and monocytes, as well as disaggregation of an existing platelet/tumor thrombus. Our observations may provide a novel antimetastatic strategy through lysing activated platelets in the tumor microenvironment using humanized anti-GPIIIa49-66 scFv Ab.
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Huang WY, Peng TI, Weng WC, Chien YY, Wu CL, Lee M, Chen KH. Higher leukocyte count is associated with higher risk of 3-year mortality in non-diabetic patients with first-ever ischemic stroke. J Neurol Sci 2012; 316:93-8. [PMID: 22336697 DOI: 10.1016/j.jns.2012.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 01/13/2012] [Accepted: 01/19/2012] [Indexed: 12/01/2022]
Abstract
Leukocyte count predicted the risk of first-time myocardial infarction and ischemic stroke. The aim of this study was to determine the role of elevated leukocyte count in non-diabetic patients admitted for acute first-ever ischemic stroke on clinical presentation and 3-year mortality. We studied 462 patients with acute first-ever ischemic stroke without diabetes mellitus or active infection at admission. Patients were classified into 2 groups according to their leukocyte count. A white blood cell (WBC) count ≥ 10,000/μL was defined as an elevated leukocyte count, otherwise as normal. Clinical presentation, risk factors for stroke, laboratory data, co-morbidities, and outcomes were recorded. 64 patients (13.9%) had elevated leukocytes. Multivariate logistic regression showed that an elevated platelet count was positively associated with the elevated leukocyte count, while a low serum sodium level was negatively associated with an elevated leukocyte count (P=0.008, P=0.003, respectively). An elevated leukocyte count was associated with a higher risk of a stroke in evolution (P=0.021). Multivariate Cox regression analysis revealed that an elevated leukocyte count is a significant predictor of 3-year mortality [P=0.010, HR=3.26 (1.33-7.98)]. In conclusion, higher leukocyte counts during the acute stroke stage are associated with increased risk of 3-year mortality in patients with acute, first-ever ischemic stroke.
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Affiliation(s)
- Wen-Yi Huang
- Department of Neurology, Chang-Gung Memorial Hospital, Keelung branch, Taiwan, School of Medicine, Chang-Gung University, Taiwan
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St Hill CA, Baharo-Hassan D, Farooqui M. C2-O-sLeX glycoproteins are E-selectin ligands that regulate invasion of human colon and hepatic carcinoma cells. PLoS One 2011; 6:e16281. [PMID: 21283832 PMCID: PMC3023807 DOI: 10.1371/journal.pone.0016281] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 12/09/2010] [Indexed: 01/22/2023] Open
Abstract
Similar to mechanisms of recruitment of activated leukocytes to inflamed tissues, selectins mediate adhesion and extravasation of circulating cancer cells. Our objective was to determine whether sialyl Lewis X modified core 2 O-glycans (C2-O-sLeX) present on colon and hepatic carcinoma cells promote their adhesion and invasion. We examined membrane expression of C2-O-sLeX, selectin binding, invasion of human colon and hepatic carcinoma cell lines, and mRNA levels of alpha-2,3 fucosyltransferase (FucT-III) and core 2 beta-1,6 N-acetylglucosaminyltransferase (C2GnT1) genes, necessary for C2-O-sLeX synthesis, by quantitative reverse-transcriptase (RT) PCR. Synthesis of core 2 branched O-glycans decorated by sLeX is dependent on C2GnT1 function and thus we determined enzyme activity of C2GnT1. The cell lines that expressed C2GnT1 and FucT-III mRNA by quantitative RT-PCR were highly positive for C2-O-sLeX by flow cytometry, and colon carcinoma cells possessed highly active C2GnT1 enzyme. Cells bound avidly to E-selection but not to P- and L-selectin. Gene knock-down of C2GnT1 in colon and hepatic carcinoma cells using short hairpin RNAs (shRNA) resulted in a 40–90% decrease in C2-O-sLeX and a 30–50% decrease in E-selectin binding compared to control cells. Invasion of hepatic and colon carcinoma cells containing C2GnT1 shRNA was significantly reduced compared to control cells in Matrigel assays and C2GnT1 activity was down-regulated in the latter cells. The sLeX epitope was predominantly distributed on core 2 O-glycans on colon and hepatic carcinoma cells. Our findings indicate that C2GnT1 gene expression and the resulting C2-O-sLeX carbohydrates produced mediate the adhesive and invasive behaviors of human carcinomas which may influence their metastatic potential.
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Affiliation(s)
- Catherine A St Hill
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, United States of America.
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The Pathophysiological Relevance of Monocyte-platelet Interactions in Inflammatory Disease. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.jecm.2010.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Macey MG, Wolf SI, Lawson C. Microparticle formation after exposure of blood to activated endothelium under flow. Cytometry A 2010; 77:761-8. [PMID: 20653016 DOI: 10.1002/cyto.a.20919] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Increased numbers of circulating microparticles (MPs) are indicative of poor clinical outcome in a number of inflammatory disorders, including atherosclerosis. Platelets and megakaryocytes are a major source of MP and are identified by presence of CD42b on the MP surface. MP shed from activated platelets can be identified by presence of P-selectin (CD62P). Tissue factor (TF) is the principal initiator of blood coagulation and its activity has been identified in MPs derived from patient plasma, which may contribute to thrombosis. Here, we have investigated by flow cytometry the expression of TF and CD62P on MP after exposure of diluted whole blood to TNF-activated endothelial cells (EC) both under static conditions and in our newly established model of flow. MPs were significantly increased in blood subjected to flow and this was further enhanced after exposure of blood to TNF-activated EC. MP surface expression of CD62P or TF was upregulated following exposure to TNF-activated EC under flow compared with flow with nonactivated EC or after static coculture with and without prior EC activation. These data strongly suggest that interactions of blood with inflamed EC can modulate production of CD62P and TF bearing MP under flow conditions, and thus may contribute to a prothrombotic environment.
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Affiliation(s)
- Marion G Macey
- Department of Haematology, The Royal London Hospital, London, UK
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Vollmar B, Menger MD. The hepatic microcirculation: mechanistic contributions and therapeutic targets in liver injury and repair. Physiol Rev 2009; 89:1269-339. [PMID: 19789382 DOI: 10.1152/physrev.00027.2008] [Citation(s) in RCA: 342] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The complex functions of the liver in biosynthesis, metabolism, clearance, and host defense are tightly dependent on an adequate microcirculation. To guarantee hepatic homeostasis, this requires not only a sufficient nutritive perfusion and oxygen supply, but also a balanced vasomotor control and an appropriate cell-cell communication. Deteriorations of the hepatic homeostasis, as observed in ischemia/reperfusion, cold preservation and transplantation, septic organ failure, and hepatic resection-induced hyperperfusion, are associated with a high morbidity and mortality. During the last two decades, experimental studies have demonstrated that microcirculatory disorders are determinants for organ failure in these disease states. Disorders include 1) a dysregulation of the vasomotor control with a deterioration of the endothelin-nitric oxide balance, an arterial and sinusoidal constriction, and a shutdown of the microcirculation as well as 2) an overwhelming inflammatory response with microvascular leukocyte accumulation, platelet adherence, and Kupffer cell activation. Within the sequelae of events, proinflammatory mediators, such as reactive oxygen species and tumor necrosis factor-alpha, are the key players, causing the microvascular dysfunction and perfusion failure. This review covers the morphological and functional characterization of the hepatic microcirculation, the mechanistic contributions in surgical disease states, and the therapeutic targets to attenuate tissue injury and organ dysfunction. It also indicates future directions to translate the knowledge achieved from experimental studies into clinical practice. By this, the use of the recently introduced techniques to monitor the hepatic microcirculation in humans, such as near-infrared spectroscopy or orthogonal polarized spectral imaging, may allow an early initiation of treatment, which should benefit the final outcome of these critically ill patients.
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Affiliation(s)
- Brigitte Vollmar
- Institute for Experimental Surgery, University of Rostock, Rostock, Germany.
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Inomata H, Takei M, Nakamura H, Fujiwara S, Shiraiwa H, Kitamura N, Hirohata S, Masuda H, Takeuchi J, Sawada S. Epstein-Barr-Virus-Infected CD15 (Lewis X)-Positive Hodgkin-Lymphoma-Like B Cells in Patients with Rheumatoid Arthritis. Open Rheumatol J 2009; 3:41-7. [PMID: 19771179 PMCID: PMC2745567 DOI: 10.2174/1874312900903010041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 04/14/2009] [Accepted: 08/06/2009] [Indexed: 11/22/2022] Open
Abstract
Patients with rheumatoid arthritis (RA), especially those who are treated with methotrexate (MTX), might have an increased risk of Hodgkin lymphoma (HL), a malignancy that is associated with Epstein-Barr virus (EBV). Here we describe a monoclonal EBV-infected B-lymphoblastoid cell line (LCL) called TKS-1 that was established from cells that spontaneously converted from an MTX-treated RA patient. TKS-1 has properties similar to HL cells and it is distinctly different from control LCLs established from normal individuals. TKS-1 cells express the HL -associated surface markers CD15 and CD30 (Takei et al. 1989). Like Hodgkin Reed-Sternberg (H-RS) cells of EBV-positive HL, TKS-1 cells express EBNA1 mRNA transcribed from the Qp promoter of the virus, whereas control LCLs use the Cp or Wp promoter to transcribe mRNA. TKS-1 cells can proliferate in an anchorage-independent manner and possess a cloning efficiency comparable to that of the Burkitt lymphoma (BL) line Raji. In addition, two EBV-positive LCLs established by cocultivated CD34+ cells isolated from the bone marrow of patients with RA and peripheral blood B lymphocytes from a healthy EBV-seronegative individual also expressed CD15. These results indicate that EBV-infected B-lymphoblastoid cells from patients with RA tend to acquire properties similar to HL cells.
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Affiliation(s)
- Hirotake Inomata
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
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Escolar G, Rao GH, Nieuwenhuis HK, White JG. Ultrastructural expression of P-selectin on surface activated platelets. Platelets 2009; 7:297-301. [DOI: 10.3109/09537109609023592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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31
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Simon PM. Section Review: Biologicals & Immunologicals: Complex carbohydrates in development as human pharmaceuticals. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.3.3.223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dyugovskaya L, Polyakov A, Lavie P, Lavie L. Delayed Neutrophil Apoptosis in Patients with Sleep Apnea. Am J Respir Crit Care Med 2008; 177:544-54. [DOI: 10.1164/rccm.200705-675oc] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Platelets and lymphocytes reciprocally regulate mutual functions, i.e., platelet-lymphocyte cross-talk. The heterotypic interactions have emerged as important regulatory mechanisms in the pathophysiological processes of thrombosis, inflammation, immunity, and atherosclerosis. Platelets influence lymphocyte function via direct cell-cell contact and/or soluble mediators. Hence, platelets enhance adhesion and cell migration of T(H), T cytolytic (T(C)), NK, and B cells. Platelets affect other functional aspects of lymphocyte subpopulations in a complex manner. They may attenuate cytokine secretion and immunosuppressive responses of T(H) cells and enhance T(C) cell proliferation and cytotoxicity. Platelets promote isotype shifting and antibody production of B cells but ameliorate cytolytic activity of NK cells. On the other hand, lymphocytes can also regulate platelet aggregation and secretion, as well as the effector cell function of platelets in immune defense. The two cell types collaborate in transcellular phospholipid metabolism, CD40-CD40 ligand-mediated intercellular signaling, and their involvements in atherogenesis. The research perspectives of platelet-lymphocyte cross-talk have also been addressed.
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Affiliation(s)
- Nailin Li
- Clinical Pharmacology Unit, Karolinska University Hospital (Solna), SE-171 76 Stockholm, Sweden.
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Htun P, Fateh-Moghadam S, Tomandl B, Handschu R, Klinger K, Stellos K, Garlichs C, Daniel W, Gawaz M. Course of platelet activation and platelet-leukocyte interaction in cerebrovascular ischemia. Stroke 2006; 37:2283-7. [PMID: 16888273 DOI: 10.1161/01.str.0000236638.75591.61] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Platelet activation plays a crucial role in the pathophysiology of cerebral ischemia. The aim of this study was to investigate the contribution of platelet activation and leukocyte-platelet interactions to the disease. METHODS One hundred thirty-five patients with transient ischemic attack (TIA) or stroke were enrolled in this single-center study. They underwent cranial computer tomography within 24 hours of clinical onset and after 3 months, and systemic venous blood samples were drawn. Platelet activation (CD62P expression), leukocyte activation (L-selectin expression), and the appearance of platelet-specific antigens on leukocytes as an index of platelet-leukocyte aggregation were measured by flow cytometric techniques in the acute state and at 3-month follow-up. RESULTS Patients with a completed stroke or TIA had significantly increased circulating platelet-leukocyte aggregates, increased P-selectin expression on platelets, and decreased L-selectin expression in the acute state compared with the control group (healthy volunteers). No differences in regard to the tested activation markers could be detected between patients with stroke or TIA in the acute phase of the disease. However, platelet and leukocyte activations were normalized after 3 months in patients with TIA, whereas leukocyte activation (reduced L-selectin expression) remained in stroke patients. CONCLUSIONS In patients with TIA and completed stroke, platelet and leukocyte activation is substantially enhanced in the acute phase of the disease. The sustained leukocyte activation observed in stroke but not in TIA patients at 3-month follow up might play a pathophysiological role in the course of the disease.
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Affiliation(s)
- Patrik Htun
- Medizinische Klinik mit Schwerpunkt Nephrologie und Intensivmedizin, Charité-Campus Virchow-Klinikum, Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Germany.
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Yanagisawa M, Taga T, Nakamura K, Ariga T, Yu RK. Characterization of glycoconjugate antigens in mouse embryonic neural precursor cells. J Neurochem 2005; 95:1311-20. [PMID: 16219035 DOI: 10.1111/j.1471-4159.2005.03452.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neuronal and glial cells organizing the central nervous system (CNS) are generated from common neural precursor cells (NPCs) during neural development. However, the expression of cell-surface glycoconjugates that are crucial for determining the properties and biological function of these cells at different stages of development has not been clearly defined. In this study, we investigated the expression of several stage-specific glycoconjugate antigens, including several b-series gangliosides GD3, 9-O-acetyl GD3, GT1b and GQ1b, stage-specific embryonic antigen-1 (SSEA-1) and HNK-1, in mouse embryonic NPCs employing immunocytochemistry and flow cytometry. In addition, several of these antigens were positively identified by chemical means for the first time. We further showed that the SSEA-1 immunoreactivity was contributed by both glycoprotein and glycolipid antigens, and that of HNK-1 was contributed only by glycoproteins. Functionally, SSEA-1 may participate in migration of the cells from neurospheres in an NPC cell culture system, and the effect could be repressed by anti-SSEA-1 antibody. Based on this observation, we identified beta1 integrin as one of the SSEA-1 carrier glycoproteins. Our data thus provide insights into the functional role of certain glycoconjugate antigens in NPCs during neural development.
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Affiliation(s)
- Makoto Yanagisawa
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA
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Kanao H, Enomoto T, Kimura T, Fujita M, Nakashima R, Ueda Y, Ueno Y, Miyatake T, Yoshizaki T, Buzard GS, Tanigami A, Yoshino K, Murata Y. Overexpression of LAMP3/TSC403/DC-LAMP promotes metastasis in uterine cervical cancer. Cancer Res 2005; 65:8640-5. [PMID: 16204031 DOI: 10.1158/0008-5472.can-04-4112] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
LAMP3 (DC-LAMP, TSC403, CD208) was originally isolated as a gene specifically expressed in lung tissues. LAMP3 is located on a chromosome 3q segment that is frequently amplified in some human cancers, including uterine cervical cancer. Because two other members of the LAMP family of lysosomal membrane glycoproteins, LAMP1 and LAMP2, were previously implicated in potentially modulating the interaction of vascular endothelial and cancer cells, we hypothesized that LAMP3 might also play an important part in metastasis. To clarify the metastatic potential of LAMP3 in cervical cancers, we transfected a LAMP3 expression vector into a human uterine cervical cancer cell line, TCS. In an in vitro invasion assay, the migration of LAMP3-overexpressing TCS cells was significantly higher than in control TCS cells. In an in vivo metastasis assay, distant metastasis was detected in 9 of 11 LAMP3-overexpressing TCS cell-injected mice and in only 1 of 11 control mice. Histologic study showed that LAMP3-overexpressing cells readily invaded into the lymph-vascular space. In clinical samples, quantitative real-time reverse transcription-PCR (RT-PCR) analyses showed that LAMP3 mRNA was significantly up-regulated in 47 of 47 (100%) cervical cancers and in 2 of 15 (13%) cervical intraepithelial neoplasias, compared with a low level of LAMP3 mRNA expressed in normal uterine cervixes. Interestingly, high LAMP3 expression was significantly correlated with the overall survival of patients with stage I/II cervical cancers. These findings indicate that LAMP3 overexpression is associated with an enhanced metastatic potential and may be a prognostic factor for cervical cancer.
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Affiliation(s)
- Hiroyuki Kanao
- Department of Obstetrics and Gynecology, Osaka University Faculty of Medicine, Osaka, Japan
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Cai S, Dole VS, Bergmeier W, Scafidi J, Feng H, Wagner DD, Davis AE. A Direct Role for C1 Inhibitor in Regulation of Leukocyte Adhesion. THE JOURNAL OF IMMUNOLOGY 2005; 174:6462-6. [PMID: 15879149 DOI: 10.4049/jimmunol.174.10.6462] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasma C1 inhibitor (C1INH) is a natural inhibitor of complement and contact system proteases. Heterozygosity for C1INH deficiency results in hereditary angioedema, which is mediated by bradykinin. Treatment with plasma C1INH is effective not only in patients with hereditary angioedema, but also in a variety of other disease models, in which such therapy is accompanied by diminished neutrophil infiltration. The underlying mechanism has been explained primarily as a result of the inhibition of the complement and contact systems. We have shown that C1INH expresses the sialyl-Lewis(x) tetrasaccharide on its N-linked glycan, via which it binds to E- and P-selectins and interferes with leukocyte-endothelial adhesion in vitro. Here we show that both native C1INH and reactive center cleaved C1INH significantly inhibit selectin-mediated leukocyte adhesion in several in vitro and in vivo models, whereas N-deglycosylated C1INH loses such activities. The data support the hypothesis that C1INH plays a direct role in leukocyte-endothelial cell adhesion, that the activity is mediated by carbohydrate, and that it is independent of protease inhibitory activity. Direct involvement of C1INH in modulation of selectin-mediated cell adhesion may be an important mechanism in the physiologic suppression of inflammation, and may partially explain its utility in therapy of inflammatory diseases.
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Affiliation(s)
- Shenghe Cai
- The CBR Institute for Biomedical Research, Harvard Medical School, Boston, MA 02115, USA
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Kappelmayer J, Nagy B, Miszti-Blasius K, Hevessy Z, Setiadi H. The emerging value of P-selectin as a disease marker. Clin Chem Lab Med 2005; 42:475-86. [PMID: 15202782 DOI: 10.1515/cclm.2004.082] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Activated platelets are key components in many arterial disorders. P-selectin is an activation-dependent platelet receptor, which is also identified in endothelial cells. Together with E- and L-selectin it constitutes the selectin family. These transmembrane proteins have continued to attract great interest as they support rapid and reversible cell adhesion in flow systems and thus play an essential role in multicellular interactions during thrombosis and inflammation. Similarly to other lectins, selectins bind to different glycoconjugates with varying affinities. Protein ligands, equipped with the appropriate carbohydrate and sulfate moieties for P-selectin binding, have been identified in normal peripheral blood leukocytes and several non-hematopoietic organs, as well as on cancer cells. For diagnostic purposes, P-selectin can readily be detected on the platelet surface by flow cytometry and by ELISA as a soluble ligand in the plasma. Along with other markers, these data can be used in the assessment of platelet activation status. Such results bear clinical significance since P-selectin has been implicated in the pathogenesis of wide-spread disorders including coronary artery disease, stroke, diabetes and malignancy.
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Affiliation(s)
- János Kappelmayer
- Department of Clinical Biochemistry and Molecular Pathology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
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Wira CR, Crane-Godreau MA, Grant KS. Endocrine Regulation of the Mucosal Immune System in the Female Reproductive Tract. Mucosal Immunol 2005. [DOI: 10.1016/b978-012491543-5/50101-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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40
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Gawaz M. Platelets and Inflammation. PLATELET FUNCTION 2005. [PMCID: PMC7122515 DOI: 10.1007/978-1-59259-917-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Platelets play a major physiological role in control of vascular integrity at the site of vascular lesions. However, the pathophysiological role of platelets is much broader than regulation of hemostasis and thrombosis. Platelets are critical elements in linking and modulating thrombosis, inflammation, and tissue repair. Platelets are stimulated by a variety of agonists including thrombin or ADP and also by inflammatory agents such as antibodies, complement, bacteria, and others. Platelets contribute to inflammation by interacting with inflammatory cells via adhesion and secretion of prestored proinflammatory mediators. Thus, platelets are critical elements in the pathophysiology of inflammation and modulate significantly a variety of inflammatory diseases. A profound understanding of the molecular mechanisms underlying the role of platelet in inflammation may result in new therapeutic strategies in acute and chronic inflammatory diseases.
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41
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Furie B, Furie BC. Role of platelet P-selectin and microparticle PSGL-1 in thrombus formation. Trends Mol Med 2004; 10:171-8. [PMID: 15059608 DOI: 10.1016/j.molmed.2004.02.008] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
P-selectin and P-selectin glycoprotein ligand 1 (PSGL-1) are vascular adhesion molecules that play an important role in leukocyte-endothelial and leukocyte-platelet interaction during the inflammatory response. Their functions are now known to include a role in thrombus formation, specifically in relation to fibrin generation and propagation. Recent findings have demonstrated that leukocyte-derived microparticles, bearing both tissue factor and PSGL-1, circulate in the blood and accumulate in the developing platelet-rich thrombus following vessel wall injury, thus concentrating tissue factor at the site of vascular injury and initiating blood coagulation.
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Affiliation(s)
- Bruce Furie
- Center for Hemostasis, Thrombosis and Vascular Biology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
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Yazdanparast R, Mianabadi M. The effect of the active component of Dendrostellera lessertii on the adhesive property of human platelets and HL-60 cells. Life Sci 2004; 75:733-9. [PMID: 15172181 DOI: 10.1016/j.lfs.2004.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2003] [Accepted: 01/28/2004] [Indexed: 10/26/2022]
Abstract
To evaluate the mediation of cell adhesion by Dendrostellera lessertii, an anti-cancer medicinal plant in Iranian folk medicine, the adhesion of thrombin activated human platelets to the cultured monocytes or HL-60 cells was investigated under the effect of the plant extract (0.4 mg/ml) and one of its purified components, 3-hydrgenkwadaphnin (0.2 nM). Treatment of the platelets with the plant extract or/3-hydrgenkwadaphnin, for various time intervals, followed by their activation by thrombin resulted in 80-90% reduction in the number of monocytes with more than 10 attached platelets. Similarly, under almost all identical conditions, the adhesion of the activated platelets to HL-60 cells was decreased by 90%. The adhesion of thrombin activated platelets to the plant extract treated HL-60 cells was also reduced significantly (95%). These data clearly indicates that Dendrostellera lessertii is capable of mediating tumor metastasis through affecting the adhesion properties of the cells.
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Affiliation(s)
- Razieh Yazdanparast
- Institute of Biochemistry and Biophysics, P.O. Box 13145 - 1384 University of Tehran, Tehran, Iran.
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43
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Rauch U, Wolff UM, Schultheiss HP, Schwimmbeck PL. Leukocyte CD15 Expression and Platelet Activation in the Coronary Sinus after Coronary Intervention. PATHOPHYSIOLOGY OF HAEMOSTASIS AND THROMBOSIS 2003; 33:109-15. [PMID: 14624053 DOI: 10.1159/000073855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2002] [Accepted: 03/06/2003] [Indexed: 11/19/2022]
Abstract
Markers associated with coronary restenosis must be identified to develop therapeutic strategies for improving the clinical outcome. We studied whether adhesion proteins on leukocytes and platelets from coronary sinus blood were associated with restenosis after coronary intervention in patients with stable coronary artery disease. Adhesion proteins on platelets and leukocytes were measured by flow cytometry. Pre- and postinterventional leukocyte CD15 expression was significantly higher in patients with restenosis than in those without it. Increased leukocyte CD15 expression during the intervention may contribute to coronary restenosis. Inhibition of leukocyte adhesion may be useful for the prevention of restenosis.
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Affiliation(s)
- Ursula Rauch
- Department of Cardiology and Pulmonology, University Hospital Benjamin Franklin, Free University of Berlin, Berlin, Germany.
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44
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Falati S, Liu Q, Gross P, Merrill-Skoloff G, Chou J, Vandendries E, Celi A, Croce K, Furie BC, Furie B. Accumulation of tissue factor into developing thrombi in vivo is dependent upon microparticle P-selectin glycoprotein ligand 1 and platelet P-selectin. J Exp Med 2003; 197:1585-98. [PMID: 12782720 PMCID: PMC2193915 DOI: 10.1084/jem.20021868] [Citation(s) in RCA: 552] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Using a laser-induced endothelial injury model, we examined thrombus formation in the microcirculation of wild-type and genetically altered mice by real-time in vivo microscopy to analyze this complex physiologic process in a system that includes the vessel wall, the presence of flowing blood, and the absence of anticoagulants. We observe P-selectin expression, tissue factor accumulation, and fibrin generation after platelet localization in the developing thrombus in arterioles of wild-type mice. However, mice lacking P-selectin glycoprotein ligand 1 (PSGL-1) or P-selectin, or wild-type mice infused with blocking P-selectin antibodies, developed platelet thrombi containing minimal tissue factor and fibrin. To explore the delivery of tissue factor into a developing thrombus, we identified monocyte-derived microparticles in human platelet-poor plasma that express tissue factor, PSGL-1, and CD14. Fluorescently labeled mouse microparticles infused into a recipient mouse localized within the developing thrombus, indicating that one pathway for the initiation of blood coagulation in vivo involves the accumulation of tissue factor- and PSGL-1-containing microparticles in the platelet thrombus expressing P-selectin. These monocyte-derived microparticles bind to activated platelets in an interaction mediated by platelet P-selectin and microparticle PSGL-1. We propose that PSGL-1 plays a role in blood coagulation in addition to its known role in leukocyte trafficking.
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Affiliation(s)
- Shahrokh Falati
- Center for Hemostasis and Thrombosis Research, Research East 319, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA
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45
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Wang YC, Kao SH, Hsieh HJ. A chemical surface modification of chitosan by glycoconjugates to enhance the cell-biomaterial interaction. Biomacromolecules 2003; 4:224-31. [PMID: 12625716 DOI: 10.1021/bm0256294] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The use of wheat germ agglutinin (WGA), a lectin molecule, to modify chitosan and enhance the cell-biomaterial interaction was examined. The percentage of living fibroblast cells on the surfaces of tissue culture polystyrene (TCPS) control, WGA-modified chitosan, and unmodified chitosan films increased to 99%, 99%, and 85%, respectively, after seeding for 48 h. DNA staining revealed that a portion of fibroblasts cultivated on chitosan films( )were undergoing apoptosis. In contrast, fibroblasts growing on WGA-modified chitosan film surfaces did not show any indication of apoptosis. The number of fibroblast cells was the highest on the WGA-modified chitosan surfaces, followed by the TCPS and unmodified chitosan surfaces. This WGA-mediated enhancement on the fibroblast cell-biomaterial interaction was cell type dependent. Other types of cells may need different lectin molecules for enhanced interaction with biomaterials. Further, the evaluation of the heat shock protein (HSP) mRNA expression indicated that HSP 90 expression was increased in the fibroblast cells cultivated on chitosan films and decreased to basal levels on the WGA-modified chitosan films. Taken together, our data suggest that the use of WGA and other lectin molecules to enhance the cell-biomaterial interaction via oligosaccharide-mediated cell adhesion is a promising way to improve cell adhesion and proliferation, the two key issues in tissue engineering.
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Affiliation(s)
- Yu-Chi Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
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46
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Macey M, McCarthy D, Azam U, Milne T, Golledge P, Newland A. Ethylenediaminetetraacetic acid plus citrate-theophylline-adenosine-dipyridamole (EDTA-CTAD): a novel anticoagulant for the flow cytometric assessment of platelet and neutrophil activation ex vivo in whole blood. CYTOMETRY. PART B, CLINICAL CYTOMETRY 2003; 51:30-40. [PMID: 12500295 DOI: 10.1002/cyto.b.10001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ethylenediaminetetraacetic acid (EDTA) is the anticoagulant recommended for full blood counts, citrate is recommended for coagulation and platelet studies, and citrate-theophylline-adenosine-dipyridamole (CTAD) inhibits platelet activation. Because the combination of EDTA and CTAD (E/C) is better than EDTA or CTAD alone for measuring platelet parameters on the ADVIA 120 Haematology System, we investigated whether it also offers advantages for the flow cytometric assessment of platelet and/or neutrophil activation and platelet-leucocyte aggregate formation ex vivo. Blood from healthy subjects was collected into E/C or citrate, kept at room temperature or at 4 degrees C, and analysed 0 to 360 min later in the ADVIA 120 and by immunofluorescent flow cytometry. Platelet count, mean platelet volume, number of platelet clumps, mean platelet component, numbers of CD62P(+) platelets and platelet-leucocyte aggregates, and expression of CD11b on neutrophils changed little over 360 min in blood with E/C kept at 4 degrees C. In contrast, one or more parameter changed when blood was kept with E/C at ambient temperature or with citrate at either temperature. The use of E/C in in vitro and in vivo studies is illustrated. Platelet and neutrophil activation status ex vivo can be reliably assessed if blood is collected into E/C, held at 4 degrees C, and analysed within 6 h.
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Affiliation(s)
- Marion Macey
- Department of Haematology, The Royal London Hospital, Whitechapel, London, United Kingdom.
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47
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Unger FM. The chemistry of oligosaccharide ligands of selectins: significance for the development of new immunomodulatory medicines. Adv Carbohydr Chem Biochem 2002; 57:207-435. [PMID: 11836943 DOI: 10.1016/s0065-2318(01)57018-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- F M Unger
- Institute of Chemistry and Center for Ultrastructure Research, Agricultural University, Vienna, Austria
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Sarma J, Laan CA, Alam S, Jha A, Fox KAA, Dransfield I. Increased platelet binding to circulating monocytes in acute coronary syndromes. Circulation 2002; 105:2166-71. [PMID: 11994250 DOI: 10.1161/01.cir.0000015700.27754.6f] [Citation(s) in RCA: 261] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Present therapies for acute coronary syndromes aim toward limiting platelet-platelet adhesion and aggregation processes. However, platelet-leukocyte interactions may contribute importantly to disease progression in the arterial wall. Recent studies suggest that prevention of platelet-leukocyte binding via P-selectin glycoprotein ligand-1 (PSGL-1) may be beneficial in animal models of vascular injury. METHODS AND RESULTS P-selectin-PSGL-1 interactions were found to account for most platelet-monocyte binding observed in peripheral blood samples from healthy donors. However, a significant component of observed adhesion was calcium independent, involving neither PSGL-1 nor P-selectin. Platelet-monocyte interactions were examined in 52 patients admitted within 14 hours of symptom onset, with acute coronary syndromes defined as unstable angina (n=12) and acute myocardial infarction (n=13) or noncardiac chest pain (n=27). When compared with patients with noncardiac chest pain, significantly elevated levels of platelet-monocyte binding were found in patients with acute myocardial infarction (70.1+/-15.4% versus 45.4+/-23.3%; P<0.01) and unstable angina (67.4+/-12.9% versus 45.4+/-23.3%; P>0.01). Calcium-independent platelet-monocyte binding was significantly elevated in myocardial infarction patients alone (14.7+/-7.7% versus 6.1+/-5.96%; P<0.001). CONCLUSIONS There is evidence for a significant P-selectin-independent molecular component to the platelet-monocyte conjugation observed in peripheral blood. Patients with myocardial infarction and unstable angina demonstrate increased total binding of platelets to monocytes. Additionally, calcium-independent adhesion was significantly elevated in patients with evidence of myocardial infarction. These findings demonstrate that novel cation-independent adhesion mechanisms may mediate platelet-monocyte binding, representing a new therapeutic target after vascular injury associated with myocardial infarction.
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Affiliation(s)
- Jaydeep Sarma
- Medical Research Council Centre for Inflammation Research, University of Edinburgh Medical School, Edinburgh, UK.
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49
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Schön MP, Krahn T, Schön M, Rodriguez ML, Antonicek H, Schultz JE, Ludwig RJ, Zollner TM, Bischoff E, Bremm KD, Schramm M, Henninger K, Kaufmann R, Gollnick HPM, Parker CM, Boehncke WH. Efomycine M, a new specific inhibitor of selectin, impairs leukocyte adhesion and alleviates cutaneous inflammation. Nat Med 2002; 8:366-72. [PMID: 11927942 DOI: 10.1038/nm0402-366] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Specific interference with molecular mechanisms guiding tissue localization of leukocytes may be of great utility for selective immunosuppressive therapies. We have discovered and characterized efomycines, a new family of selective small-molecule inhibitors of selectin functions. Members of this family significantly inhibited leukocyte adhesion in vitro. Efomycine M, which was nontoxic and showed the most selective inhibitory effects on selectin-mediated leukocyte-endothelial adhesion in vitro, significantly diminished rolling in mouse ear venules in vivo as seen by intravital microscopy. In addition, efomycine M alleviated cutaneous inflammation in two complementary mouse models of psoriasis, one of the most common chronic inflammatory skin disorders. Molecular modeling demonstrated a spatial conformation of efomycines mimicking naturally occurring selectin ligands. Efomycine M might be efficacious in the treatment of human inflammatory disorders through a similar mechanism.
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Affiliation(s)
- Michael P Schön
- Department of Dermatology, Otto-von-Guericke-University, Magdeburg, Germany.
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50
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Lerouge I, Vanderleyden J. O-antigen structural variation: mechanisms and possible roles in animal/plant-microbe interactions. FEMS Microbiol Rev 2002; 26:17-47. [PMID: 12007641 DOI: 10.1111/j.1574-6976.2002.tb00597.x] [Citation(s) in RCA: 322] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Current data from bacterial pathogens of animals and from bacterial symbionts of plants support some of the more general proposed functions for lipopolysaccharides (LPS) and underline the importance of LPS structural versatility and adaptability. Most of the structural heterogeneity of LPS molecules is found in the O-antigen polysaccharide. In this review, the role and mechanisms of this striking flexibility in molecular structure of the O-antigen in bacterial pathogens and symbionts are illustrated by some recent findings. The variation in O-antigen that gives rise to an enormous structural diversity of O-antigens lies in the sugar composition and the linkages between monosaccharides. The chemical composition and structure of the O-antigen is strain-specific (interstrain LPS heterogeneity) but can also vary within one bacterial strain (intrastrain LPS heterogeneity). Both LPS heterogeneities can be achieved through variations at different levels. First of all, O-polysaccharides can be modified non-stoichiometrically with sugar moieties, such as glucosyl and fucosyl residues. The addition of non-carbohydrate substituents, i.e. acetyl or methyl groups, to the O-antigen can also occur with regularity, but in most cases these modifications are again non-stoichiometric. Understanding LPS structural variation in bacterial pathogens is important because several studies have indicated that the composition or size of the O-antigen might be a reliable indicator of virulence potential and that these important features often differ within the same bacterial strain. In general, O-antigen modifications seem to play an important role at several (at least two) stages of the infection process, including the colonization (adherence) step and the ability to bypass or overcome host defense mechanisms. There are many reports of modifications of O-antigen in bacterial pathogens, resulting either from altered gene expression, from lysogenic conversion or from lateral gene transfer followed by recombination. In most cases, the mechanisms underlying these changes have not been resolved. However, in recent studies some progress in understanding has been made. Changes in O-antigen structure mediated by lateral gene transfer, O-antigen conversion and phase variation, including fucosylation, glucosylation, acetylation and changes in O-antigen size, will be discussed. In addition to the observed LPS heterogeneity in bacterial pathogens, the structure of LPS is also altered in bacterial symbionts in response to signals from the plant during symbiosis. It appears to be part of a molecular communication between bacterium and host plant. Experiments ex planta suggest that the bacterium in the rhizosphere prepares its LPS for its roles in symbiosis by refining the LPS structure in response to seed and root compounds and the lower pH at the root surface. Moreover, modifications in LPS induced by conditions associated with infection are another indication that specific structures are important. Also during the differentiation from bacterium to bacteroid, the LPS of Rhizobium undergoes changes in the composition of the O-antigen, presumably in response to the change of environment. Recent findings suggest that, during symbiotic bacteroid development, reduced oxygen tension induces structural modifications in LPS that cause a switch from predominantly hydrophilic to predominantly hydrophobic molecular forms. However, the genetic mechanisms by which the LPS epitope changes are regulated remain unclear. Finally, the possible roles of O-antigen variations in symbiosis will be discussed.
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Affiliation(s)
- Inge Lerouge
- Centre of Microbial and Plant Genetics, Katholieke Universtiteit Leuven, Kasteelpark Arenberg 20, B-3001, Heverlee, Belgium
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