251
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Romo GM, Dong JF, Schade AJ, Gardiner EE, Kansas GS, Li CQ, McIntire LV, Berndt MC, López JA. The glycoprotein Ib-IX-V complex is a platelet counterreceptor for P-selectin. J Exp Med 1999; 190:803-14. [PMID: 10499919 PMCID: PMC2195629 DOI: 10.1084/jem.190.6.803] [Citation(s) in RCA: 228] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/1999] [Accepted: 07/20/1999] [Indexed: 11/30/2022] Open
Abstract
We have identified platelet glycoprotein (GP) Ibalpha as a counterreceptor for P-selectin. GP Ibalpha is a component of the GP Ib-IX-V complex, which mediates platelet adhesion to subendothelium at sites of injury. Cells expressing P-selectin adhered to immobilized GP Ibalpha, and GP Ibalpha-expressing cells adhered to and rolled on P-selectin and on histamine-stimulated endothelium in a P-selectin-dependent manner. In like manner, platelets rolled on activated endothelium, a phenomenon inhibited by antibodies to both P-selectin and GP Ibalpha. Unlike the P-selectin interaction with its leukocyte ligand, PSGL-1 (P-selectin glycoprotein ligand 1), the interaction with GP Ibalpha required neither calcium nor carbohydrate core-2 branching or alpha(1,3)-fucosylation. The interaction was inhibited by sulfated proteoglycans and by antibodies against GP Ibalpha, including one directed at a tyrosine-sulfated region of the polypeptide. Thus, the GP Ib-IX-V complex mediates platelet attachment to both subendothelium and activated endothelium.
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Affiliation(s)
- Gabriel M. Romo
- Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
| | - Jing-Fei Dong
- Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
| | - Alicia J. Schade
- Cox Laboratory for Bioengineering, Rice University, Houston, Texas 77251
| | | | - Geoffrey S. Kansas
- Department of Microbiology/Immunology, Northwestern University Medical School, Chicago, Illinois 60611
| | - Chester Q. Li
- Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
| | - Larry V. McIntire
- Cox Laboratory for Bioengineering, Rice University, Houston, Texas 77251
| | - Michael C. Berndt
- Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
- Baker Medical Research Institute, Melbourne, Australia 3181
| | - José A. López
- Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030
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252
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Uhlmann S, Uhlmann D, Spiegel HU. Evaluation of hepatic microcirculation by in vivo microscopy. J INVEST SURG 1999; 12:179-93. [PMID: 10501077 DOI: 10.1080/089419399272458] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In vivo microscopy is an excellent technique for investigating the microcirculation and until recently the only one that allowed direct visualization. Rat liver has been widely studied, because microcirculatory disorders play a pivotal role in the pathogenesis of organ failure during hepatic ischemia, transplantation, hemorrhagic shock, endotoxemia, and sepsis. The state of the microcirculation is an important prognostic factor for the reestablishment of organ function after these injuries. This article introduces the most common procedures for in vivo microscopy of the rat liver, summarizes the available fluorescent dyes, and gives an overview of criteria for the expression and evaluation of microscopic findings. Particular emphasis is given to a description of the different parameters assessed by direct observation of hepatic microcirculation, such as perfusion rate, leukocyte-endothelium interactions, leukocyte velocities, and phagocytic activity. Examples of normal range values are given. This overview is intended to help those wanting to introduce this method into their research and who are embarking on intravital microscopy for the first time, and to enable them to decide which techniques are appropriate for answering special questions.
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Affiliation(s)
- S Uhlmann
- Department of Ophthalmology, University of Leipzig, Germany.
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253
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Aydemir-Koksoy A, Koksoy C, Kuzu MA, Demirpence E, Cinel I, Kesenci M, Yavuzer S. Intestinal ischemia-reperfusion leads to platelet dysfunction. Thromb Res 1999; 94:395-400. [PMID: 10390135 DOI: 10.1016/s0049-3848(99)00012-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- A Aydemir-Koksoy
- Department of Physiology, Ankara University Medical School, Turkey.
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254
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Abstract
Under normal conditions, platelets do not adhere to endothelium. However, when platelets or endothelial cells are stimulated by thrombin or cytokines, respectively, platelets bind avidly to endothelium. Because there is accumulating evidence that endothelial cells may become apoptotic under certain proinflammatory or prothrombotic conditions, we investigated whether endothelial cells undergoing apoptosis may become proadhesive for nonactivated platelets. Human umbilical vein endothelial cells (HUVEC) were induced to undergo apoptosis by staurosporine, a nonspecific protein kinase inhibitor, or by culture in suspension with serum-deprivation. After treatment of HUVEC or platelets with different receptor antagonists, nonactivated, washed human platelets were allowed to adhere to HUVEC for 20 minutes. To exclude matrix involvement, platelet binding was measured in suspension by using flow cytometry. Independent of the method of apoptosis induction, there was a marked increase in platelet binding to apoptotic HUVEC. Although HUVEC exhibited maximal adhesiveness for platelets after 2 to 4 hours, complete DNA fragmentation of HUVEC occurred only several hours later. Adhesion assays after blockade of different platelet receptors showed only involvement of β1-integrins. Platelet binding to apoptotic HUVEC was inhibited by more than 70% when platelets were treated with blocking anti-β1 antibodies. Treatment of apoptotic HUVEC with blocking antibodies to different potential platelet receptors, including known ligands for β1-integrins, did not affect platelet binding. As assessed by determination of β-thromboglobulin and platelet factor 4 in the supernatants, platelets bound to apoptotic HUVEC became slightly activated. However, significant expression of platelet P-selectin (CD62P) was not found. These data provide further evidence that endothelial cells undergoing apoptosis may contribute to thrombotic events.
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255
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Abstract
Leukocyte adhesion to endothelium is essential for the development of an appropriate immune-inflammatory response. The vital importance of leukocyte-endothelial adhesive interactions in host defense and homeostasis is illustrated by the clinical manifestations of patients with congenital defects of leukocyte adhesion functions. However, under some circumstances leukocyte adhesion to endothelium may instead lead to vascular and tissue damage. In recent years, there has been remarkable progress in the understanding of the molecular basis of leukocyte adhesion to endothelium, and this knowledge has led to a new approach to immunomodulation in human disease, ie 'antiadhesion' therapy. This review focuses on cell adhesion molecules mediating adhesion of circulating phagocytes to vascular endothelium, on congenital defects of phagocyte adhesion in man, and on the current status of antiadhesion therapy directed towards phagocyte and endothelial adhesion molecules. We will also consider markers of phagocyte activation, which may provide a means to identify those patients who would benefit most from antiadhesion therapy.
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Affiliation(s)
- H Repo
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Finland.
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256
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Abstract
AbstractUnder normal conditions, platelets do not adhere to endothelium. However, when platelets or endothelial cells are stimulated by thrombin or cytokines, respectively, platelets bind avidly to endothelium. Because there is accumulating evidence that endothelial cells may become apoptotic under certain proinflammatory or prothrombotic conditions, we investigated whether endothelial cells undergoing apoptosis may become proadhesive for nonactivated platelets. Human umbilical vein endothelial cells (HUVEC) were induced to undergo apoptosis by staurosporine, a nonspecific protein kinase inhibitor, or by culture in suspension with serum-deprivation. After treatment of HUVEC or platelets with different receptor antagonists, nonactivated, washed human platelets were allowed to adhere to HUVEC for 20 minutes. To exclude matrix involvement, platelet binding was measured in suspension by using flow cytometry. Independent of the method of apoptosis induction, there was a marked increase in platelet binding to apoptotic HUVEC. Although HUVEC exhibited maximal adhesiveness for platelets after 2 to 4 hours, complete DNA fragmentation of HUVEC occurred only several hours later. Adhesion assays after blockade of different platelet receptors showed only involvement of β1-integrins. Platelet binding to apoptotic HUVEC was inhibited by more than 70% when platelets were treated with blocking anti-β1 antibodies. Treatment of apoptotic HUVEC with blocking antibodies to different potential platelet receptors, including known ligands for β1-integrins, did not affect platelet binding. As assessed by determination of β-thromboglobulin and platelet factor 4 in the supernatants, platelets bound to apoptotic HUVEC became slightly activated. However, significant expression of platelet P-selectin (CD62P) was not found. These data provide further evidence that endothelial cells undergoing apoptosis may contribute to thrombotic events.
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257
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Abstract
Recombinant human thrombopoietin, or pegylated recombinant human megakaryocyte growth and development factor, produces log-linear increases in megakaryocytopiesis and platelet production. Recent clinical studies investigating the efficacy, safety, and cost benefit of administering platelet growth factors indicate that appropriate dosing of pegylated recombinant human megakaryocyte growth and development factor, or recombinant human thrombopoietin, during chemotherapeutic marrow suppression produces these increases in four ways. First, these factors improve ensuant thrombocytopenia without producing platelet-dependent thrombo-occlusive complications. Second, recombinant human thrombopoietin or pegylated recombinant human megakaryocyte growth and development factor mobilize hematopoietic progenitor cells into the peripheral blood. Third, chronic dosing of HIV-infected thrombocytopenic patients with pegylated recombinant human megakaryocyte growth and development factor normalizes peripheral platelet counts without antibody formation. Fourth, the administration of pegylated recombinant human megakaryocyte growth and development factor to normal human volunteer platelet donors increases platelet yields nearly fourfold, with corresponding increases in peripheral platelet counts when transfused into thrombocytopenic recipients. The clinical application of platelet growth factors is continuing to be defined.
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Affiliation(s)
- L A Harker
- Division of Hematology and Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
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258
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Stone PCW, Nash GB. Conditions under which immobilized platelets activate as well as capture flowing neutrophils. Br J Haematol 1999. [DOI: 10.1111/j.1365-2141.1999.01375.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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259
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Massberg S, Sausbier M, Klatt P, Bauer M, Pfeifer A, Siess W, Fässler R, Ruth P, Krombach F, Hofmann F. Increased adhesion and aggregation of platelets lacking cyclic guanosine 3',5'-monophosphate kinase I. J Exp Med 1999; 189:1255-64. [PMID: 10209042 PMCID: PMC2193024 DOI: 10.1084/jem.189.8.1255] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Atherosclerotic vascular lesions are considered to be a major cause of ischemic diseases, including myocardial infarction and stroke. Platelet adhesion and aggregation during ischemia-reperfusion are thought to be the initial steps leading to remodeling and reocclusion of the postischemic vasculature. Nitric oxide (NO) inhibits platelet aggregation and smooth muscle proliferation. A major downstream target of NO is cyclic guanosine 3', 5'-monophosphate kinase I (cGKI). To test the intravascular significance of the NO/cGKI signaling pathway in vivo, we have studied platelet-endothelial cell and platelet-platelet interactions during ischemia/reperfusion using cGKI-deficient (cGKI-/-) mice. Platelet cGKI but not endothelial or smooth muscle cGKI is essential to prevent intravascular adhesion and aggregation of platelets after ischemia. The defect in platelet cGKI is not compensated by the cAMP/cAMP kinase pathway supporting the essential role of cGKI in prevention of ischemia-induced platelet adhesion and aggregation.
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Affiliation(s)
- S Massberg
- Institut für Chirurgische Forschung der Ludwig-Maximilians-Universität München, 81377 München, Germany
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260
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Menger MD, Vollmar B. Contusion of skeletal muscle increases leukocyte-endothelial cell interactions: an intravital-microscopy study in rats. THE JOURNAL OF TRAUMA 1999; 46:742. [PMID: 10217250 DOI: 10.1097/00005373-199904000-00039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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261
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Kirk AD. Immunosuppression without immunosuppression? How to be a tolerant individual in a dangerous world. Transpl Infect Dis 1999; 1:65-75. [PMID: 11428972 DOI: 10.1034/j.1399-3062.1999.10107.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The field of transplantation has developed based on two principles: allografts are rejected because they express foreign antigens, and the immune system must be suppressed to prevent rejection. Recently, in vitro and in vivo experimental evidence has accumulated that calls both of these beliefs into question. This article reviews an alternative approach to transplantation that focuses on tissue injury as the instigator of graft rejection and employs physiological mechanisms of tolerance to avoid graft loss. Methods that allow for defense against infectious microbes while at the same time allowing for graft survival are proposed. In particular, the rationale behind the use of anti-CD154 antibody treatment is highlighted. A model is introduced that takes into consideration the experimental successes seen with anti-CD154 therapies.
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Affiliation(s)
- A D Kirk
- Naval Medical Research Center, Bethesda, Maryland 20889, USA.
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262
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Corso CO, Okamoto S, Rüttinger D, Messmer K. Hypertonic saline dextran attenuates leukocyte accumulation in the liver after hemorrhagic shock and resuscitation. THE JOURNAL OF TRAUMA 1999; 46:417-23. [PMID: 10088843 DOI: 10.1097/00005373-199903000-00011] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Hemorrhagic shock and resuscitation triggers a global ischemia/reperfusion phenomenon, in which activated leukocytes are considered strong contributors to the ensuing tissue damage. METHODS The aim of the study was to investigate the effects of hypertonic saline dextran (HSD) on the early leukocyte/endothelial interactions (intravital fluorescence microscopy) in a rat model of hemorrhagic shock (1 hour at mean arterial pressure of 40 mm Hg). The resuscitation was performed with lactated Ringer's solution (RL, four times shed blood/20 minutes, n = 6), 6% dextran 60 (DEX, 100% shed blood/5 minutes, n = 8), and 7.2% NaCl/10% dextran 60 (HSD, 10% shed blood/2 minutes, n = 8). RESULTS After 1 hour of resuscitation, shock-induced stasis/adherence of leukocytes was further enhanced with RL (sinusoids 17.6+/-6.9%; venules 33.9+/-8.5%), whereas DEX and HSD attenuated leukocyte stagnation in sinusoids (DEX -7.4+/-6,1%; HSD -14.7+/-2.9%, p<0.01 vs. RL) and leukocyte adherence in postsinusoidal venules (DEX -12.2+/-8.6%, p<0.05 vs. RL; HSD -27+/-7.4%, p<0.01 vs. RL). CONCLUSION HSD reduced significantly the number of leukocytes accumulated in the liver after resuscitation of hemorrhagic shock, probably due to a combination of mechanisms of both components.
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Affiliation(s)
- C O Corso
- Institute for Surgical Research, Munich University, Germany
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