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Hellen N, Mashanov GI, Conte IL, le Trionnaire S, Babich V, Knipe L, Mohammed A, Ogmen K, Martin-Almedina S, Török K, Hannah MJ, Molloy JE, Carter T. P-selectin mobility undergoes a sol-gel transition as it diffuses from exocytosis sites into the cell membrane. Nat Commun 2022; 13:3031. [PMID: 35641503 PMCID: PMC9156680 DOI: 10.1038/s41467-022-30669-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
In response to vascular damage, P-selectin molecules are secreted onto the surface of cells that line our blood vessels. They then serve as mechanical anchors to capture leucocytes from the blood stream. Here, we track individual P-selectin molecules released at the surface of live endothelial cells following stimulated secretion. We find P-selectin initially shows fast, unrestricted diffusion but within a few minutes, movement becomes increasingly restricted and ~50% of the molecules become completely immobile; a process similar to a sol-gel transition. We find removal of the extracellular C-type lectin domain (ΔCTLD) and/or intracellular cytoplasmic tail domain (ΔCT) has additive effects on diffusive motion while disruption of the adapter complex, AP2, or removal of cell-surface heparan sulphate restores mobility of full-length P-selectin close to that of ΔCT and ΔCTLD respectively. We have found P-selectin spreads rapidly from sites of exocytosis and evenly decorates the cell surface, but then becomes less mobile and better-suited to its mechanical anchoring function. P-selectin recruits leucocytes to regions of blood vessel damage. Using single molecule imaging, we find newly secreted P-selectin spreads rapidly across the plasma membrane and then becomes immobilized and better-suited to leucocyte capture.
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Affiliation(s)
| | | | - Ianina L Conte
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Sophie le Trionnaire
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Victor Babich
- Mercy College of Health Sciences, Des Moines, IA, USA
| | | | - Alamin Mohammed
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Kazim Ogmen
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Silvia Martin-Almedina
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Katalin Török
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK
| | - Matthew J Hannah
- Microbiology Services Colindale, Public Health England, London, UK
| | | | - Tom Carter
- Molecular and Clinical Sciences Research Institute, St Georges University of London, London, UK.
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2
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Thromboinflammation Model-on-A-Chip by Whole Blood Microfluidics on Fixed Human Endothelium. Diagnostics (Basel) 2021; 11:diagnostics11020203. [PMID: 33573079 PMCID: PMC7911484 DOI: 10.3390/diagnostics11020203] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/23/2020] [Accepted: 01/26/2021] [Indexed: 01/15/2023] Open
Abstract
Microfluidic devices have an established role in the study of platelets and coagulation factors in thrombosis, with potential diagnostic applications. However, few microfluidic devices have assessed the contribution of neutrophils to thrombus formation, despite increasing knowledge of neutrophils’ importance in cardiovascular thrombosis. We describe a thromboinflammation model which uses straight channels, lined with fixed human umbilical vein endothelial cells, after treatment with tumour necrosis factor-alpha. Re-calcified whole blood is perfused over the endothelium at venous and arterial shear rate. Neutrophil adhesion, platelet and fibrin thrombus formation, is measured over time by the addition of fluorescent antibodies to a whole blood sample. Fixed endothelium retains surface expression of adhesion molecules ICAM-1 and E-Selectin. Neutrophils adhere preferentially to platelet thrombi on the endothelium. Inhibitors of neutrophil adhesion and anti-inflammatory agents, such as isoquercetin, decrease neutrophil adhesion. Our model offers the advantage of the use of (1) fixed endothelium, (2) whole blood, instead of isolated neutrophils, and (3) a small amount of blood (1 mL). The characteristics of this thromboinflammation model provide the potential for further development for drug screening and point-of-care applications.
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3
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Aguilar G, Koning T, Ehrenfeld P, Sánchez FA. Role of NO and S-nitrosylation in the Expression of Endothelial Adhesion Proteins That Regulate Leukocyte and Tumor Cell Adhesion. Front Physiol 2020; 11:595526. [PMID: 33281627 PMCID: PMC7691576 DOI: 10.3389/fphys.2020.595526] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 10/20/2020] [Indexed: 12/11/2022] Open
Abstract
Leukocyte recruitment is one of the most important cellular responses to tissue damage. Leukocyte extravasation is exquisitely regulated by mechanisms of selective leukocyte-endothelium recognition through adhesion proteins in the endothelial cell surface that recognize specific integrins in the activated leukocytes. A similar mechanism is used by tumor cells during metastasis to extravasate and form a secondary tumor. Nitric oxide (NO) has been classically described as an anti-inflammatory molecule that inhibits leukocyte adhesion. However, the evidence available shows also a positive role of NO in leukocyte adhesion. These apparent discrepancies might be explained by the different NO concentrations reached during the inflammatory response, which are highly modulated by the expression of different nitric oxide synthases, along the inflammatory response and by changes in their subcellular locations.
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Affiliation(s)
- Gaynor Aguilar
- Instituto de Inmunología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Tania Koning
- Instituto de Inmunología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Ehrenfeld
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.,Centro Interdisciplinario de Estudios del Sistema Nervioso, Universidad Austral de Chile, Valdivia, Chile
| | - Fabiola A Sánchez
- Instituto de Inmunología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.,Centro Interdisciplinario de Estudios del Sistema Nervioso, Universidad Austral de Chile, Valdivia, Chile
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4
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Endothelial signaling by neutrophil-released oncostatin M enhances P-selectin-dependent inflammation and thrombosis. Blood Adv 2020; 3:168-183. [PMID: 30670533 DOI: 10.1182/bloodadvances.2018026294] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/13/2018] [Indexed: 12/25/2022] Open
Abstract
In the earliest phase of inflammation, histamine and other agonists rapidly mobilize P-selectin to the apical membranes of endothelial cells, where it initiates rolling adhesion of flowing neutrophils. Clustering of P-selectin in clathrin-coated pits facilitates rolling. Inflammatory cytokines typically signal by regulating gene transcription over a period of hours. We found that neutrophils rolling on P-selectin secreted the cytokine oncostatin M (OSM). The released OSM triggered signals through glycoprotein 130 (gp130)-containing receptors on endothelial cells that, within minutes, further clustered P-selectin and markedly enhanced its adhesive function. Antibodies to OSM or gp130, deletion of the gene encoding OSM in hematopoietic cells, or conditional deletion of the gene encoding gp130 in endothelial cells inhibited neutrophil rolling on P-selectin in trauma-stimulated venules of the mouse cremaster muscle. In a mouse model of P-selectin-dependent deep vein thrombosis, deletion of OSM in hematopoietic cells or of gp130 in endothelial cells markedly inhibited adhesion of neutrophils and monocytes and the rate and extent of thrombus formation. Our results reveal a paracrine-signaling mechanism by which neutrophil-released OSM rapidly influences endothelial cell function during physiological and pathological inflammation.
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5
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The Interaction of Selectins and PSGL-1 as a Key Component in Thrombus Formation and Cancer Progression. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6138145. [PMID: 28680883 PMCID: PMC5478826 DOI: 10.1155/2017/6138145] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/12/2017] [Accepted: 04/23/2017] [Indexed: 12/11/2022]
Abstract
Cellular interaction is inevitable in the pathomechanism of human disease. Formation of heterotypic cellular aggregates, between distinct cells of hematopoietic and nonhematopoietic origin, may be involved in events leading to inflammation and the complex process of cancer progression. Among adhesion receptors, the family of selectins with their ligands have been considered as one of the major contributors to cell-cell interactions. Consequently, the inhibition of the interplay between selectins and their ligands may have potential therapeutic benefits. In this review, we focus on the current evidence on the selectins as crucial modulators of inflammatory, thrombotic, and malignant disorders. Knowing that there is promiscuity in selectin binding, we outline the importance of a key protein that serves as a ligand for all selectins. This dimeric mucin, the P-selectin glycoprotein ligand 1 (PSGL-1), has emerged as a major player in inflammation, thrombus, and cancer development. We discuss the interaction of PSGL-1 with various selectins in physiological and pathological processes with particular emphasis on mechanisms that lead to severe disease.
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6
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Alshafie W, Chappe FG, Li M, Anini Y, Chappe VM. VIP regulates CFTR membrane expression and function in Calu-3 cells by increasing its interaction with NHERF1 and P-ERM in a VPAC1- and PKCε-dependent manner. Am J Physiol Cell Physiol 2014; 307:C107-19. [DOI: 10.1152/ajpcell.00296.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Vasoactive intestinal peptide (VIP) is a topical airway gland secretagogue regulating fluid secretions, primarily by stimulating cystic fibrosis transmembrane conductance regulator (CFTR)-dependent chloride secretion that contributes to the airways innate defense mechanism. We previously reported that prolonged VIP stimulation of pituitary adenylate cyclase-activating peptide receptors (VPAC1) in airway cells enhances CFTR function by increasing its membrane stability. In the present study, we identified the key effectors in the VIP signaling cascade in the human bronchial serous cell line Calu-3. Using immunocytochemistry and in situ proximity ligation assays, we found that VIP stimulation increased CFTR membrane localization by promoting its colocalization and interaction with the scaffolding protein Na+/H+ exchange factor 1 (NHERF1), a PDZ protein known as a positive regulator for CFTR membrane localization. VIP stimulation also increased phosphorylation, by protein kinase Cε of the actin-binding protein complex ezrin/radixin/moesin (ERM) and its interaction with NHERF1 and CFTR complex. On the other hand, it reduced intracellular CFTR colocalization and interaction with CFTR associated ligand, another PDZ protein known to compete with NHERF1 for CFTR interaction, inducing cytoplasmic retention and lysosomal degradation. Reducing NHERF1 or ERM expression levels by specific siRNAs prevented the VIP effect on CFTR membrane stability. Furthermore, iodide efflux assays confirmed that NHERF1 and P-ERM are necessary for VIP regulation of the stability and sustained activity of membrane CFTR. This study shows the cellular mechanism by which prolonged VIP stimulation of airway epithelial cells regulates CFTR-dependent secretions.
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Affiliation(s)
- Walaa Alshafie
- Departments of Physiology and Biophysics, Dalhousie University, Nova Scotia, Canada and
| | - Frederic G. Chappe
- Departments of Physiology and Biophysics, Dalhousie University, Nova Scotia, Canada and
| | - Mansong Li
- Departments of Physiology and Biophysics, Dalhousie University, Nova Scotia, Canada and
| | - Younes Anini
- Departments of Physiology and Biophysics, Dalhousie University, Nova Scotia, Canada and
- Obstetrics and Gynecology, Dalhousie University, Nova Scotia, Canada
| | - Valerie M. Chappe
- Departments of Physiology and Biophysics, Dalhousie University, Nova Scotia, Canada and
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7
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Zhang Y, Jiang N, Zarnitsyna VI, Klopocki AG, McEver RP, Zhu C. P-selectin glycoprotein ligand-1 forms dimeric interactions with E-selectin but monomeric interactions with L-selectin on cell surfaces. PLoS One 2013; 8:e57202. [PMID: 23451187 PMCID: PMC3581448 DOI: 10.1371/journal.pone.0057202] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 01/18/2013] [Indexed: 11/19/2022] Open
Abstract
Interactions of selectins with cell surface glycoconjugates mediate the first step of the adhesion and signaling cascade that recruits circulating leukocytes to sites of infection or injury. P-selectin dimerizes on the surface of endothelial cells and forms dimeric bonds with P-selectin glycoprotein ligand-1 (PSGL-1), a homodimeric sialomucin on leukocytes. It is not known whether leukocyte L-selectin or endothelial cell E-selectin are monomeric or oligomeric. Here we used the micropipette technique to analyze two-dimensional binding of monomeric or dimeric L- and E-selectin with monomeric or dimeric PSGL-1. Adhesion frequency analysis demonstrated that E-selectin on human aortic endothelial cells supported dimeric interactions with dimeric PSGL-1 and monomeric interactions with monomeric PSGL-1. In contrast, L-selectin on human neutrophils supported monomeric interactions with dimeric or monomeric PSGL-1. Our work provides a new method to analyze oligomeric cross-junctional molecular binding at the interface of two interacting cells.
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Affiliation(s)
- Yan Zhang
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
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8
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Calosso M, Charpentier D, Vaillancourt M, Bencheqroun M, St-Pierre G, Wilkes BC, Guindon Y. A new approach to explore the binding space of polysaccharide-based ligands: selectin antagonists. ACS Med Chem Lett 2012; 3:1045-9. [PMID: 24900426 DOI: 10.1021/ml300263x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/11/2012] [Indexed: 01/11/2023] Open
Abstract
The discovery of molecules that interfere with the binding of a ligand to a receptor remains a topic of great interest in medicinal chemistry. Herein, we report that a monosaccharide unit of a polysaccharide ligand can be replaced advantageously by a conformationally locked acyclic molecular entity. A cyclic component of the selectin ligand Sialyl Lewis(x), GlcNAc, is replaced by an acyclic tether, tartaric esters, which link two saccharide units. The conformational bias of this acyclic tether originates from the minimization of intramolecular dipole-dipole interaction and the gauche effect. The evaluation of the binding of these derivatives to P-selectin was measured by surface plasmon resonance spectroscopy. The results obtained in our pilot study suggest that the discovery of tunable tethers could facilitate the exploration of the carbohydrate recognition domain of various receptors.
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Affiliation(s)
| | | | | | | | | | | | - Yvan Guindon
- Département de Chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
- Department of Chemistry, McGill University, Montréal, Québec H3A 2K6, Canada
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9
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Suzuki Y, Okuro K, Takeuchi T, Aida T. Friction-Mediated Dynamic Disordering of Phospholipid Membrane by Mechanical Motions of Photoresponsive Molecular Glue: Activation of Ion Permeation. J Am Chem Soc 2012; 134:15273-6. [DOI: 10.1021/ja3074424] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yushi Suzuki
- Department of Chemistry and Biotechnology,
School of
Engineering, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kou Okuro
- Department of Chemistry and Biotechnology,
School of
Engineering, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tadashi Takeuchi
- Department of Chemistry and Biotechnology,
School of
Engineering, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Takuzo Aida
- Department of Chemistry and Biotechnology,
School of
Engineering, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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10
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Sundd P, Pospieszalska MK, Cheung LSL, Konstantopoulos K, Ley K. Biomechanics of leukocyte rolling. Biorheology 2011; 48:1-35. [PMID: 21515934 DOI: 10.3233/bir-2011-0579] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Leukocyte rolling on endothelial cells and other P-selectin substrates is mediated by P-selectin binding to P-selectin glycoprotein ligand-1 expressed on the tips of leukocyte microvilli. Leukocyte rolling is a result of rapid, yet balanced formation and dissociation of selectin-ligand bonds in the presence of hydrodynamic shear forces. The hydrodynamic forces acting on the bonds may either increase (catch bonds) or decrease (slip bonds) their lifetimes. The force-dependent 'catch-slip' bond kinetics are explained using the 'two pathway model' for bond dissociation. Both the 'sliding-rebinding' and the 'allosteric' mechanisms attribute 'catch-slip' bond behavior to the force-induced conformational changes in the lectin-EGF domain hinge of selectins. Below a threshold shear stress, selectins cannot mediate rolling. This 'shear-threshold' phenomenon is a consequence of shear-enhanced tethering and catch bond-enhanced rolling. Quantitative dynamic footprinting microscopy has revealed that leukocytes rolling at venular shear stresses (>0.6 Pa) undergo cellular deformation (large footprint) and form long tethers. The hydrodynamic shear force and torque acting on the rolling cell are thought to be synergistically balanced by the forces acting on tethers and stressed microvilli, however, their relative contribution remains to be determined. Thus, improvement beyond the current understanding requires in silico models that can predict both cellular and microvillus deformation and experiments that allow measurement of forces acting on individual microvilli and tethers.
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Affiliation(s)
- Prithu Sundd
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
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11
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Abstract
Rolling adhesion on vascular surfaces is the first step in recruiting circulating leukocytes, hematopoietic progenitors, or platelets to specific organs or to sites of infection or injury. Rolling requires the rapid yet balanced formation and dissociation of adhesive bonds in the challenging environment of blood flow. This review explores how structurally distinct adhesion receptors interact through mechanically regulated kinetics with their ligands to meet these challenges. Remarkably, increasing force applied to adhesive bonds first prolongs their lifetimes (catch bonds) and then shortens their lifetimes (slip bonds). Catch bonds mediate the counterintuitive phenomenon of flow-enhanced rolling adhesion. Force-regulated disruptions of receptor interdomain or intradomain interactions remote from the ligand-binding surface generate catch bonds. Adhesion receptor dimerization, clustering in membrane domains, and interactions with the cytoskeleton modulate the forces applied to bonds. Both inside-out and outside-in cell signals regulate these processes.
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Affiliation(s)
- Rodger P McEver
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA.
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12
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Hussain KM, Leong KLJ, Ng MML, Chu JJH. The essential role of clathrin-mediated endocytosis in the infectious entry of human enterovirus 71. J Biol Chem 2010; 286:309-21. [PMID: 20956521 DOI: 10.1074/jbc.m110.168468] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Little is currently known about the infectious entry process of human enterovirus 71 (HEV71) into host cells, which may represent potential anti-viral targeting sites. In this study a targeted small-interfering RNA (siRNA) screening platform assay was established and validated to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics, and endosomal trafficking essential for HEV71 infection. Screen evaluation was conducted via the expression of well characterized dominant-negative mutants, bioimaging studies (double-labeled immunofluorescence assays, transmission electron microscopy analysis), secondary siRNA-based dosage dependence studies, and drug inhibition assays. The infectious entry of HEV71 into rhabdomyosarcoma cells was shown to be significantly inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis (CME) that include AP2A1, ARRB1, CLTC, CLTCL1, SYNJ1, ARPC5, PAK1, ROCK1, and WASF1. The functional role of CME was verified by the observation of strong co-localization between HEV71 particles and clathrin as well as dose-dependent inhibition of HEV71 infection upon siRNA knockdown of CME-associated genes. HEV71 entry by CME was further confirmed via inhibition by dominant-negative EPS15 mutants and treatment of CME drug inhibitors, with more than 80% inhibition observed at 20 μm chlorpromazine. Furthermore, HEV71 infection was shown to be sensitive to the disruption of human genes in regulating early to late endosomal trafficking as well as endosomal acidic pH. The identification of clathrin-mediated endocytosis as the entry pathway for HEV71 infection of susceptible host cells contributes to a better understanding of HEV71 pathogenesis and enables future development of anti-viral strategies against HEV71 infection.
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Affiliation(s)
- Khairunnisa' Mohamed Hussain
- Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597
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13
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Sharma J, Rastogi P, Creer MH, McHowat J. Polymorphonuclear leukocytes isolated from umbilical cord blood as a useful research tool to study adherence to cell monolayers. J Immunol Methods 2009; 351:30-5. [PMID: 19800347 DOI: 10.1016/j.jim.2009.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 09/22/2009] [Accepted: 09/24/2009] [Indexed: 10/20/2022]
Abstract
One of the initial steps in the inflammatory process involves the adherence and transmigration of circulating polymorphonuclear leukocytes (PMN) across the endothelial cell monolayer. One of the main constituents of the neutrophil phagosome that contributes to bacterial killing is myeloperoxidase (MPO) which can be measured spectrophotometrically, using hydrogen peroxide as a substrate, and hence can be used as an index to quantify neutrophil adherence. To evaluate whether PMN isolated from umbilical cord blood could be used for in vitro experiments to monitor neutrophil adherence, we compared the adherence to confluent endothelial and epithelial cell monolayers using PMN isolated from umbilical cord and adult peripheral blood. The extent of PMN adherence was assessed by measuring MPO activity. In initial experiments, we isolated PMN from umbilical cord and adult peripheral blood and measured MPO activity with respect to cell number and assay incubation times. Our data demonstrate that PMN obtained from either source had similar MPO activity and similar adherence to endothelial or epithelial cells. In conclusion, our data suggest that umbilical cord blood is a suitable source of leukocytes to examine PMN adherence in the setting of inflammation in a variety of disease processes.
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Affiliation(s)
- Janhavi Sharma
- Department of Pathology, Saint Louis University School of Medicine, 1402 S. grand Blvd., St Louis, Missouri 63104, USA
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14
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Alon R. Chapter 6 Membrane–Cytoskeletal Platforms for Rapid Chemokine Signaling to Integrins. CURRENT TOPICS IN MEMBRANES 2009. [DOI: 10.1016/s1063-5823(09)64006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 2008; 112:2035-45. [PMID: 18550846 DOI: 10.1182/blood-2008-04-149468] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In inflamed venules, leukocytes use P-selectin glycoprotein ligand-1 (PSGL-1) to roll on P-selectin and E-selectin and to activate integrin alphaLbeta2 (lymphocyte function-associated antigen-1, LFA-1) to slow rolling on intercellular adhesion molecule-1 (ICAM-1). Studies in cell lines have suggested that PSGL-1 requires its cytoplasmic domain to localize in membrane domains, to support rolling on P-selectin, and to signal through spleen tyrosine kinase (Syk). We generated "DeltaCD" mice that express PSGL-1 without the cytoplasmic domain. Unexpectedly, neutrophils from these mice localized PSGL-1 normally in microvilli, uropods, and lipid rafts. DeltaCD neutrophils expressed less PSGL-1 on their surfaces because of inefficient export from the endoplasmic reticulum. Limited digestion of wild-type neutrophils with O-sialoglycoprotein endopeptidase was used to reduce the PSGL-1 density to that on DeltaCD neutrophils. At matched PSGL-1 densities, both DeltaCD and wild-type neutrophils rolled similarly on P-selectin. However, DeltaCD neutrophils rolling on P-selectin did not trigger Syk-dependent activation of LFA-1 to slow rolling on ICAM-1. These data demonstrate that the PSGL-1 cytoplasmic domain is dispensable for leukocyte rolling on P-selectin but is essential to activate beta2 integrins to slow rolling on ICAM-1.
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16
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Clustering endothelial E-selectin in clathrin-coated pits and lipid rafts enhances leukocyte adhesion under flow. Blood 2007; 111:1989-98. [PMID: 18029551 DOI: 10.1182/blood-2007-09-113423] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
During inflammation, E-selectin expressed on cytokine-activated endothelial cells mediates leukocyte rolling under flow. E-selectin undergoes endocytosis and may associate with lipid rafts. We asked whether distribution of E-selectin in membrane domains affects its functions. E-selectin was internalized in transfected CHO cells or cytokine-activated human umbilical vein endothelial cells (HUVECs). Confocal microscopy demonstrated colocalization of E-selectin with alpha-adaptin, a clathrin-associated protein. Deleting the cytoplasmic domain of E-selectin or disrupting clathrin-coated pits with hypertonic medium blocked internalization of E-selectin, reduced colocalization of E-selectin with alpha-adaptin, and inhibited E-selectin-mediated neutrophil rolling under flow. Unlike CHO cells, HUVECs expressed a small percentage of E-selectin in lipid rafts. Even fewer neutrophils rolled on E-selectin in HUVECs treated with hypertonic medium and with methyl-beta-cyclodextrin, which disrupts lipid rafts. These data demonstrate that E-selectin clusters in both clathrin-coated pits and lipid rafts of endothelial cells but is internalized in clathrin-coated pits. Distribution in both domains markedly enhances E-selectin's ability to mediate leukocyte rolling under flow.
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17
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Abstract
The movement of leukocytes from the blood into peripheral tissues plays a key role in immunity as well as chronic inflammatory and autoimmune diseases. The shear force of blood flow presents special challenges to leukocytes as they establish adhesion on the vascular endothelium and migrate into the underlying tissues. Integrins are a family of cell adhesion and signaling molecules, whose function can be regulated to meet these challenges. The affinity of integrins for their vascular ligands can be stimulated in subseconds by chemoattractant signaling. This aids in inducing leukocyte adhesion under flow conditions. Further, linkage of these integrins to the actin cytoskeleton also helps to establish adhesion to the endothelium under flow conditions. In the case of alpha4beta1 integrins, this linkage of the integrin to the cytoskeleton is mediated in part by the binding of paxillin to the alpha4 integrin subunit and the subsequent binding of paxillin to the cytoskeleton molecule talin. The movement of leukocytes along the vascular endothelium and in between endothelial cells requires the temporal and spatial regulation of small guanosine triphosphatases, such as Rac1. We describe mechanisms through which alpha4beta1 integrin signaling regulates appropriate Rac activation to drive leukocyte migration.
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Affiliation(s)
- David M Rose
- Department of Medicine, University of California, and VA Healthcare System, San Diego, CA, USA
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18
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Alon R, Dustin ML. Force as a Facilitator of Integrin Conformational Changes during Leukocyte Arrest on Blood Vessels and Antigen-Presenting Cells. Immunity 2007; 26:17-27. [PMID: 17241958 DOI: 10.1016/j.immuni.2007.01.002] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Integrins comprise a large family of cell-cell and cell-matrix adhesion receptors that rapidly modulate their adhesiveness. The arrest of leukocyte integrins on target vascular beds involves instantaneous conformational switches generating shear-resistant adhesions. Structural data suggest that these integrins are maintained in low-affinity conformations and must rapidly undergo conformational switches transduced via cytoplasmic changes ("inside-out" signaling) and simultaneous ligand-induced rearrangements ("outside-in"). This bidirectional activation is accelerated by signals from endothelial chemoattractants (chemokines). Recent studies predict that shear forces in the piconewton (pN) range per integrin can facilitate these biochemical switches. After extravasation, antigen recognition involves smaller internal forces from cytoskeletal motors and actin polymers forming the immune synapse. In this review, we address how forces facilitate allosteric integrin activation by biochemical signals. Evidence suggests that preformed cytoskeletal anchorage rather than free integrin mobility is key for force-enhanced integrin activation by chemokines and TCR signals.
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Affiliation(s)
- Ronen Alon
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel.
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19
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20
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Phan UT, Waldron TT, Springer TA. Remodeling of the lectin-EGF-like domain interface in P- and L-selectin increases adhesiveness and shear resistance under hydrodynamic force. Nat Immunol 2006; 7:883-9. [PMID: 16845394 PMCID: PMC1764822 DOI: 10.1038/ni1366] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 06/22/2006] [Indexed: 02/06/2023]
Abstract
Crystal structures of the lectin and epidermal growth factor (EGF)-like domains of P-selectin show 'bent' and 'extended' conformations. An extended conformation would be 'favored' by forces exerted on a selectin bound at one end to a ligand and at the other end to a cell experiencing hydrodynamic drag forces. To determine whether the extended conformation has higher affinity for ligand, we introduced an N-glycosylation site to 'wedge open' the interface between the lectin and EGF-like domains of P-selectin. This alteration increased the affinity of P-selectin for its ligand P-selectin glycoprotein 1 (PSGL-1) and thereby the strength of P-selectin-mediated rolling adhesion. Similarly, an asparagine-to-glycine substitution in the lectin-EGF-like domain interface of L-selectin enhanced rolling adhesion under shear flow. Our results demonstrate that force, by 'favoring' an extended selectin conformation, can strengthen selectin-ligand bonds.
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Affiliation(s)
- Uyen T Phan
- CBR Institute for Biomedical Research, Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
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21
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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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22
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Gentzsch M, Chang XB, Cui L, Wu Y, Ozols VV, Choudhury A, Pagano RE, Riordan JR. Endocytic trafficking routes of wild type and DeltaF508 cystic fibrosis transmembrane conductance regulator. Mol Biol Cell 2004; 15:2684-96. [PMID: 15075371 PMCID: PMC420093 DOI: 10.1091/mbc.e04-03-0176] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Intracellular trafficking of cystic fibrosis transmembrane conductance regulator (CFTR) is a focus of attention because it is defective in most patients with cystic fibrosis. DeltaF508 CFTR, which does not mature conformationally, normally does not exit the endoplasmic reticulum, but if induced to do so at reduced temperature is short-lived at the surface. We used external epitope-tagged constructs to elucidate the itinerary and kinetics of wild type and DeltaF508 CFTR in the endocytic pathway and visualized movement of CFTR from the surface to intracellular compartments. Modulation of different endocytic steps with low temperature (16 degrees C) block, protease inhibitors, and overexpression of wild type and mutant Rab GTPases revealed that surface CFTR enters several different routes, including a Rab5-dependent initial step to early endosomes, then either Rab11-dependent recycling back to the surface or Rab7-regulated movement to late endosomes or alternatively Rab9-mediated transit to the trans-Golgi network. Without any of these modulations DeltaF508 CFTR rapidly disappears from and does not return to the cell surface, confirming that its altered structure is detected in the distal as well as proximal secretory pathway. Importantly, however, the mutant protein can be rescued at the plasma membrane by Rab11 overexpression, proteasome inhibitors, or inhibition of Rab5-dependent endocytosis.
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Affiliation(s)
- Martina Gentzsch
- Mayo Clinic College of Medicine, S.C. Johnson Medical Research Center, Department of Biochemistry and Molecular Biology, Mayo Clinic, Scottsdale, Arizona 85259, USA
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23
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Dwir O, Grabovsky V, Alon R. Selectin avidity modulation by chemokines at subsecond endothelial contacts: a novel regulatory level of leukocyte trafficking. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2004:109-35. [PMID: 14579777 DOI: 10.1007/978-3-662-05397-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- O Dwir
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel.
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24
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Setiadi H, McEver RP. Signal-dependent distribution of cell surface P-selectin in clathrin-coated pits affects leukocyte rolling under flow. ACTA ACUST UNITED AC 2003; 163:1385-95. [PMID: 14676308 PMCID: PMC2173709 DOI: 10.1083/jcb.200307178] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Flowing leukocytes roll on P-selectin that is mobilized from secretory granules to the surfaces of endothelial cells after stimulation with histamine or thrombin. Before it is internalized, P-selectin clusters in clathrin-coated pits, which enhances its ability to support leukocyte rolling. We found that thrombin and histamine induced comparable exocytosis of P-selectin on endothelial cells. However, compared with histamine, thrombin decreased the recruitment of P-selectin into clathrin-coated pits, slowed the internalization of P-selectin, and reduced the number and stability of neutrophils rolling on P-selectin. Significantly more RhoA was activated in thrombin- than in histamine-stimulated endothelial cells. Inhibitors of RhoA or its effector, Rho kinase, reversed thrombin's ability to inhibit the internalization and adhesive function of P-selectin in endothelial cells. Experiments with transfected cells confirmed that the inhibitory actions of thrombin and Rho kinase on P-selectin required its cytoplasmic domain. Thus, a signaling event affects both the function and clearance of a protein that enters the constitutive clathrin-mediated endocytic pathway.
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Affiliation(s)
- Hendra Setiadi
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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25
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Ali M, Hicks AER, Hellewell PG, Thoma G, Norman KE. Polymers carrying sLe
x
‐mimetics are superior inhibitors of E‐selectin‐dependent leukocyte rolling in vivo. FASEB J 2003; 18:152-4. [PMID: 14597557 DOI: 10.1096/fj.03-0346fje] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Selectins mediate leukocyte rolling and may represent good anti-inflammatory drug targets. Detailed knowledge regarding the structure of selectin ligands has permitted development of selectin antagonists with varying specificities and activity. Efficacy of monovalent selectin antagonists may be increased by presenting them on a polymer backbone. We have synthesized a range of multivalent selectin antagonists and characterized their activity by using intravital microscopy of the mouse cremaster muscle. The monovalent inhibitor CGP77175A inhibited E-selectin-dependent leukocyte rolling at a dose of 3 mg/kg. Multivalent presentation of CGP77175A on a modified polylysine backbone (degree of polymerization = 1200; 50% of the polylysines carry the inhibitor) greatly enhanced in vivo activity giving an inhibitor that produced an equivalent effect at 0.1 mg/kg. The polylysine conjugate was also longer acting than the monovalent antagonist. In spite of greatly enhanced activity against E-selectin compared with monovalent inhibitor, the multivalent inhibitor had no measurable effect on P- or L-selectin-dependent leukocyte rolling.
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Affiliation(s)
- Majid Ali
- Cardiovascular Research Group, Clinical Sciences Centre, Northern General Hospital, Sheffield S5 7AU, UK
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26
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Serirom S, Raharjo WH, Chotivanich K, Loareesuwan S, Kubes P, Ho M. Anti-adhesive effect of nitric oxide on Plasmodium falciparum cytoadherence under flow. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:1651-60. [PMID: 12707049 PMCID: PMC1851209 DOI: 10.1016/s0002-9440(10)64299-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/29/2003] [Indexed: 01/30/2023]
Abstract
Nitric oxide (NO) is widely known to inhibit platelet and leukocyte adhesion to endothelium through its regulatory effect on adhesion molecule expression. The objective of the present study was to investigate if NO affects the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBCs) to human microvascular endothelium (HDMECs) under flow conditions in vitro. The effect of endogenous NO was studied using the NO synthase inhibitor L-N(G)-nitro-arginine-methyl-ester (L-NAME). Treatment of HDMECs with 3 mmol/L of L-NAME for 4 hours significantly enhanced IRBC adhesion and the effect could be reversed by an anti-P-selectin but not an anti-VCAM-1 antibody. The effect of exogenous NO on cytoadherence was studied by using the NO donor 3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine (PPN). PPN (300 micro mol/L) treatment reduced the number of adherent IRBCs on resting HDMECs by down-regulating basal ICAM-1 expression, and on tumor necrosis factor-alpha-stimulated HDMECs by inhibition of VCAM-1 induction and down-regulation of ICAM-1 expression. The inhibitory effect of PPN on tumor necrosis factor-alpha-induced VCAM-1 expression at 24 hours was evident when the NO donor was added for as short as 2 hours. These findings suggest that NO may be protective against P. falciparum infection by inhibiting cytoadherence, and underscore the therapeutic potential of NO in the treatment of severe falciparum malaria.
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Affiliation(s)
- Supattra Serirom
- Department of Microbiology and Infectious Diseases and Immunology Research Group, University of Calgary, Calgary, Alberta, Canada
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27
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Burdick MM, McCaffery JM, Kim YS, Bochner BS, Konstantopoulos K. Colon carcinoma cell glycolipids, integrins, and other glycoproteins mediate adhesion to HUVECs under flow. Am J Physiol Cell Physiol 2003; 284:C977-87. [PMID: 12477667 DOI: 10.1152/ajpcell.00423.2002] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This study was undertaken to investigate the molecular constituents mediating LS174T colon adenocarcinoma cell adhesion to 4-h TNF-alpha-stimulated human umbilical vein endothelial cells (HUVECs) under flow. At 1 dyn/cm(2), approximately 57% of cells rolled and then became firmly adherent, whereas others continuously rolled on endothelium. Initial cell binding was primarily mediated by endothelial E-selectin. By using neuraminidase, glycolipid biosynthesis inhibitor d,l-threo-1-phenyl-2-hexadecanoylamino-3-pyrrolidino-1-propanol. HCl, trypsin, and flow cytometry, LS174T cells were shown to express sialyl Lewis(x) (sLe(x))- and di-sLe(x)-decorated, but not sLe(a)-decorated, glycolipid and glycoprotein ligands for E-selectin. The cells preferentially employed sialylated glycoproteins over glycolipids in adhesion as measured by conversion of rolling to firm adhesion, resistance to detachment by increased shear stress, and rolling velocity. However, a nonsialylated E-selectin counterreceptor also exists. Furthermore, LS174T alpha(2), alpha(6), and beta(1) integrins support a minor pathway in adhesion to HUVECs. Finally, tumor cell attachment specifically increases HUVEC endocytosis of E-selectin. Altogether, the data indicate the complexity of carcinoma cell-endothelium adhesion via sialylated glycoconjugates, integrins, and their respective counterreceptors.
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Affiliation(s)
- Monica M Burdick
- Department of Chemical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218-2694, USA
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28
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Yago T, Leppänen A, Qiu H, Marcus WD, Nollert MU, Zhu C, Cummings RD, McEver RP. Distinct molecular and cellular contributions to stabilizing selectin-mediated rolling under flow. J Cell Biol 2002; 158:787-99. [PMID: 12177042 PMCID: PMC2174028 DOI: 10.1083/jcb.200204041] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2002] [Revised: 07/01/2002] [Accepted: 07/01/2002] [Indexed: 11/22/2022] Open
Abstract
Leukocytes roll on selectins at nearly constant velocities over a wide range of wall shear stresses. Ligand-coupled microspheres roll faster on selectins and detach quickly as wall shear stress is increased. To examine whether the superior performance of leukocytes reflects molecular features of native ligands or cellular properties that favor selectin-mediated rolling, we coupled structurally defined selectin ligands to microspheres or K562 cells and compared their rolling on P-selectin. Microspheres bearing soluble P-selectin glycoprotein ligand (sPSGL)-1 or 2-glycosulfopeptide (GSP)-6, a GSP modeled after the NH2-terminal P-selectin-binding region of PSGL-1, rolled equivalently but unstably on P-selectin. K562 cells displaying randomly coupled 2-GSP-6 also rolled unstably. In contrast, K562 cells bearing randomly coupled sPSGL-1 or 2-GSP-6 targeted to a membrane-distal region of the presumed glycocalyx rolled more like leukocytes: rolling steps were more uniform and shear resistant, and rolling velocities tended to plateau as wall shear stress was increased. K562 cells treated with paraformaldehyde or methyl-beta-cyclodextrin before ligand coupling were less deformable and rolled unstably like microspheres. Cells treated with cytochalasin D were more deformable, further resisted detachment, and rolled slowly despite increases in wall shear stress. Thus, stable, shear-resistant rolling requires cellular properties that optimize selectin-ligand interactions.
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Affiliation(s)
- Tadayuki Yago
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 74104, USA
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29
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Abstract
Weibel-Palade bodies (WPBs) are the lysosome-related secretory organelles of endothelial cells. Their content protein von Willebrand factor, plays a key role in haemostasis, whilst P-selectin in the membranes is critical in the initiation of inflammation. Biogenesis of these rod-shaped structures is driven by von Willebrand factor, since its heterologous expression leads to formation of organelles morphologically indistinguishable from bona fide WPBs. The two main membrane proteins of WPBs, CD63 and P-selectin, have complex itineraries controlled largely by cytoplasmic targeting signals. We are only just beginning to understand the way in which these three proteins come together to form mature WPBs.
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Affiliation(s)
- Matthew J Hannah
- MRC Laboratory for Molecular Cell Biology, Cell Biology Unit, University College London, Gower Street, WC1E 6BT, London, UK
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30
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Dwir O, Steeber DA, Schwarz US, Camphausen RT, Kansas GS, Tedder TF, Alon R. L-selectin dimerization enhances tether formation to properly spaced ligand. J Biol Chem 2002; 277:21130-9. [PMID: 11907045 DOI: 10.1074/jbc.m201999200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Selectin counterreceptors are glycoprotein scaffolds bearing multiple carbohydrate ligands with exceptional ability to tether flowing cells under disruptive shear forces. Bond clusters may facilitate formation and stabilization of selectin tethers. L-selectin ligation has been shown to enhance L-selectin rolling on endothelial surfaces. We now report that monoclonal antibodies-induced L-selectin dimerization enhances L-selectin leukocyte tethering to purified physiological L-selectin ligands and glycopeptides. Microkinetic analysis of individual tethers suggests that leukocyte rolling is enhanced through the dimerization-induced increase in tether formation, rather than by tether stabilization. Notably, L-selectin dimerization failed to augment L-selectin-mediated adhesion below a threshold ligand density, suggesting that L-selectin dimerization enhanced adhesiveness only to properly clustered ligand. In contrast, an epidermal growth factor domain substitution of L-selectin enhanced tether formation to L-selectin ligands irrespective of ligand density, suggesting that this domain controls intrinsic ligand binding properties of L-selectin without inducing L-selectin dimerization. Strikingly, at low ligand densities, where L-selectin tethering was not responsive to dimerization, elevated shear stress restored sensitivity of tethering to selectin dimerization. This is the first indication that shear stress augments effective selectin ligand density at local contact sites by promoting L-selectin encounter of immobilized ligand.
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Affiliation(s)
- Oren Dwir
- Department of Immunology, Weizmann Institute of Science, Rehovot, 76100 Israel
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31
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Grabovsky V, Dwir O, Alon R. Endothelial chemokines destabilize L-selectin-mediated lymphocyte rolling without inducing selectin shedding. J Biol Chem 2002; 277:20640-50. [PMID: 12042326 DOI: 10.1074/jbc.m201763200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Chemokines presented on specialized endothelial surfaces rapidly up-regulate leukocyte integrin avidity and firm arrest through G(i)-protein signaling. Here we describe a novel, G-protein-independent, down-regulatory activity of apical endothelial chemokines in destabilizing L-selectin-mediated leukocyte rolling. Unexpectedly, this anti-adhesive chemokine suppression of rolling does not involve L-selectin shedding. Destabilization of rolling is induced only by immobilized chemokines juxtaposed to L-selectin ligands and is an energy-dependent process. Chemokines are found to interfere with a subsecond stabilization of selectin tethers necessary for persistent rolling. This is a first indication that endothelial chemokines can attenuate in situ L-selectin adhesion to endothelial ligands at subsecond contacts. This negative feedback mechanism may underlie the jerky nature of rolling mediated by L-selectin in vivo.
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Affiliation(s)
- Valentin Grabovsky
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
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32
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Radi ZA, Kehrli ME, Ackermann MR. Cell adhesion molecules, leukocyte trafficking, and strategies to reduce leukocyte infiltration. J Vet Intern Med 2002. [PMID: 11817056 DOI: 10.1111/j.1939-1676.2001.tb01586.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Leukocyte-endothelial cell interactions are mediated by various cell adhesion molecules. These interactions are important for leukocyte extravasation and trafficking in all domestic animal species. An initial slowing of leukocytes on the vascular endothelium is mediated by selectins. This event is followed by (1) activation of beta2 integrins after leukocyte exposure to cytokines and pro-inflammatory mediators, (2) adherence of leukocyte beta2 integrins to vascular endothelial ligands (eg, intercellular adhesion molecule-1 [ICAM-1]), (3) extravasation of leukocytes into tissues through tight junctions of endothelial cells mediated by platelet and endothelial cell adhesion molecule-1 (PECAM-1), and (4) perivascular migration through the extracellular matrix via beta1 integrins. Inhibiting excessive leukocyte egress and subsequent free radical-mediated damage caused by leukocyte components may attenuate or eliminate tissue damage. Several methods have been used to modify leukocyte infiltration in various animal models. These methods include nonspecific inhibition of pro-inflammatory mediators and adhesion molecules by nonsteroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids, inhibition of cytokines and cytokine receptors, and inhibition of specific types of cell adhesion molecules, with inhibitors such as peptides and antibodies to beta2 integrins, and inhibitors of selectins, ICAMs, and vascular cell adhesion molecule-1 (VCAM-1). By understanding the cellular and molecular events in leukocyte-endothelial cell interactions, therapeutic strategies are being developed in several animal models and diseases in domestic animal species. Such therapies may have clinical benefit in the future to overcome tissue damage induced by excessive leukocyte infiltration.
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Affiliation(s)
- Z A Radi
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames 50011-1250, USA
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33
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Alon R, Feigelson S. From rolling to arrest on blood vessels: leukocyte tap dancing on endothelial integrin ligands and chemokines at sub-second contacts. Semin Immunol 2002; 14:93-104. [PMID: 11978081 DOI: 10.1006/smim.2001.0346] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In order to extravasate the bloodstream at specific sites of inflammation or antigen presentation, circulating leukocytes must rapidly translate specific adhesive and stimulatory signals into firm adhesion. Leukocyte arrest is nearly exclusively mediated by integrin receptors. Recent in vitro and in vivo evidence suggests that specialized integrins support reversible tethers that slow down selectin-initiated rolling of leukocytes prior to their arrest. In situ activation of integrin avidity by ligand and chemokine signaling can take place within fractions of seconds, resulting either in augmented reversible adhesions or immediate arrest on the vascular endothelium. The ability of leukocyte integrins to rapidly respond to these in situ avidity modulators appears to depend on preformed affinity and clustering states, which are internally regulated by cytoskeletal constraints on integrin conformation and mobility. We discuss potential regulatory mechanisms by which a given set of chemokine receptors and integrins may interact to rapidly generate high avidity, shear-resistant integrin-mediated leukocyte arrest on vascular endothelium.
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Affiliation(s)
- Ronen Alon
- Department of Immunology, Weizmann Institute of Science, Rehovot, 76100 Israel.
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34
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Dwir O, Kansas GS, Alon R. Cytoplasmic anchorage of L-selectin controls leukocyte capture and rolling by increasing the mechanical stability of the selectin tether. J Cell Biol 2001; 155:145-56. [PMID: 11581291 PMCID: PMC2150804 DOI: 10.1083/jcb.200103042] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
L-selectin is a leukocyte lectin that mediates leukocyte capture and rolling in the vasculature. The cytoplasmic domain of L-selectin has been shown to regulate leukocyte rolling. In this study, the regulatory mechanisms by which this domain controls L-selectin adhesiveness were investigated. We report that an L-selectin mutant generated by truncation of the COOH-terminal 11 residues of L-selectin tail, which impairs association with the cytoskeletal protein alpha-actinin, could capture leukocytes to glycoprotein L-selectin ligands under physiological shear flow. However, the conversion of initial tethers into rolling was impaired by this partial tail truncation, and was completely abolished by a further four-residue truncation of the L-selectin tail. Physical anchorage of both cell-free tail-truncated mutants within a substrate fully rescued their adhesive deficiencies. Microkinetic analysis of full-length and truncated L-selectin-mediated rolling at millisecond temporal resolution suggests that the lifetime of unstressed L-selectin tethers is unaffected by cytoplasmic tail truncation. However, cytoskeletal anchorage of L-selectin stabilizes the selectin tether by reducing the sensitivity of its dissociation rate to increasing shear forces. Low force sensitivity (reactive compliance) of tether lifetime is crucial for selectins to mediate leukocyte rolling under physiological shear stresses. This is the first demonstration that reduced reactive compliance of L-selectin tethers is regulated by cytoskeletal anchorage, in addition to intrinsic mechanical properties of the selectin-carbohydrate bond.
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Affiliation(s)
- O Dwir
- Department of Immunology, Weizmann Institute of Science, Rehovot, 76100 Israel
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35
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Ramachandran V, Yago T, Epperson TK, Kobzdej MM, Nollert MU, Cummings RD, Zhu C, McEver RP. Dimerization of a selectin and its ligand stabilizes cell rolling and enhances tether strength in shear flow. Proc Natl Acad Sci U S A 2001; 98:10166-71. [PMID: 11481445 PMCID: PMC56933 DOI: 10.1073/pnas.171248098] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2001] [Indexed: 11/18/2022] Open
Abstract
Selectins mediate rolling of leukocytes by rapid formation and dissociation of selectin-ligand bonds, which are assumed to require high mechanical strength to prevent premature dissociation by the forces applied in shear flow. This assumption is based largely on the observation that increasing wall shear stress increases only modestly the dissociation of transient leukocyte tethers on very low selectin densities. P-selectin binds to the N-terminal region of P-selectin glycoprotein ligand-1 (PSGL-1), a mucin on leukocytes. Both PSGL-1 and P-selectin are extended homodimers. We perfused transfected cells expressing wild-type dimeric PSGL-1 or a chimeric monomeric form of PSGL-1 on immobilized dimeric or monomeric forms of P-selectin. Cells expressing dimeric or monomeric PSGL-1 tethered to P-selectin at equivalent rates. However, cells expressing dimeric PSGL-1 established more stable rolling adhesions, which were more shear resistant and exhibited less fluctuation in rolling velocities. On low densities of dimeric P-selectin, increasing wall shear stress more rapidly increased transient tether dissociation of cells expressing monomeric PSGL-1 than dimeric PSGL-1. Tether dissociation on low densities of monomeric P-selectin was even more shear sensitive. We conclude that dimerization of both PSGL-1 and P-selectin stabilizes tethering and rolling, probably by increasing rebinding within a bond cluster. Because transient tethers may have more than one bond, the mechanical strength of selectin-ligand bonds is likely to be lower than initially estimated. Tether strength may rely more on bond clusters to distribute applied force.
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Affiliation(s)
- V Ramachandran
- Warren Medical Research Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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36
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Florian V, Schlüter T, Bohnensack R. A new member of the sorting nexin family interacts with the C-terminus of P-selectin. Biochem Biophys Res Commun 2001; 281:1045-50. [PMID: 11237770 DOI: 10.1006/bbrc.2001.4467] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
P-selectin is a cell adhesion molecule found in platelets and endothelial cells mediating binding of leukocytes. It is stored in secretory granules and expressed at the plasma membrane after cell activation. After rapid internalisation P-selectin recycles or is degraded. The 35 amino acid cytoplasmic domain of P-selectin contains signals for sorting into secretory granules, for endocytosis and for delivery to lysosomes. To investigate protein-protein interactions, we performed two-hybrid screening using the cytoplasmic domain of P-selectin as bait. KIAA0064 was identified as a putative intracellular P-selectin binding protein. Because the protein contains a phox homology (PX) domain in the N-terminus which is a characteristic feature of the sorting nexin (SNX) family, it was named SNX17. The PX domain is not required for binding of P-selectin in the two-hybrid system. Expression of a fusion protein between SNX17 and green fluorescent protein demonstrated localisation of SNX17 in the cytosol and to membranes.
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Affiliation(s)
- V Florian
- Institute for Biochemistry, Medical Faculty, Otto-von-Guericke-University, Magdeburg, Germany.
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Dimerization of P-selectin in platelets and endothelial cells. Blood 2000. [DOI: 10.1182/blood.v96.9.3070.h8003070_3070_3077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
P-selectin is a leukocyte adhesion receptor stored in platelets and endothelial cells and is translocated to the surface upon cell activation. Purified P-selectin is oligomeric and has increased avidity for its ligand relative to the monomeric form, but whether P-selectin self-associates in the membrane of intact cells is not known. A chemical cross-linking approach was used to show that P-selectin is present as noncovalent dimers in resting platelets, human umbilical vein endothelial cells, and heterologous RIN5F cells expressing P-selectin. The results of 2-dimensional isoelectric focusing are consistent in showing P-selectin dimers as homodimers, but they are composed of a more basic subset of P-selectin than the monomers. This suggests that the dimers are a biochemically distinct subset of P-selectin. P-selectin dimers form in the endoplasmic reticulum and Golgi compartments of human umbilical vein endothelial cells only after synthesis of the mature P-selectin subunit, and are not preferentially stored in Weibel-Palade bodies as compared with the monomeric form. Platelet activation with thrombin receptor–activating peptide leads to the presence of P-selectin monomers and homodimers on the cell surface as well as P-selectin heterodimers, which are composed of P-selectin and an unidentified protein of approximately 81 kd molecular weight. In summary, these studies demonstrate that P-selectin is homodimeric in situ and that platelet activation leads to the formation of an additional activation-specific heterodimeric species. In addition, the homodimer has unique biochemical characteristics compared with the monomeric form, and dimerization occurs in the endoplasmic reticulum and Golgi compartments of endothelial cells.
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Abstract
AbstractP-selectin is a leukocyte adhesion receptor stored in platelets and endothelial cells and is translocated to the surface upon cell activation. Purified P-selectin is oligomeric and has increased avidity for its ligand relative to the monomeric form, but whether P-selectin self-associates in the membrane of intact cells is not known. A chemical cross-linking approach was used to show that P-selectin is present as noncovalent dimers in resting platelets, human umbilical vein endothelial cells, and heterologous RIN5F cells expressing P-selectin. The results of 2-dimensional isoelectric focusing are consistent in showing P-selectin dimers as homodimers, but they are composed of a more basic subset of P-selectin than the monomers. This suggests that the dimers are a biochemically distinct subset of P-selectin. P-selectin dimers form in the endoplasmic reticulum and Golgi compartments of human umbilical vein endothelial cells only after synthesis of the mature P-selectin subunit, and are not preferentially stored in Weibel-Palade bodies as compared with the monomeric form. Platelet activation with thrombin receptor–activating peptide leads to the presence of P-selectin monomers and homodimers on the cell surface as well as P-selectin heterodimers, which are composed of P-selectin and an unidentified protein of approximately 81 kd molecular weight. In summary, these studies demonstrate that P-selectin is homodimeric in situ and that platelet activation leads to the formation of an additional activation-specific heterodimeric species. In addition, the homodimer has unique biochemical characteristics compared with the monomeric form, and dimerization occurs in the endoplasmic reticulum and Golgi compartments of endothelial cells.
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39
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Mehta P, Cummings RD, McEver RP. Affinity and kinetic analysis of P-selectin binding to P-selectin glycoprotein ligand-1. J Biol Chem 1998; 273:32506-13. [PMID: 9829984 DOI: 10.1074/jbc.273.49.32506] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukocytes use the cell-surface mucin P-selectin glycoprotein ligand-1 (PSGL-1) to tether to and roll on P-selectin on activated endothelial cells and platelets. By using surface plasmon resonance, we measured the affinity and kinetics of binding of soluble monomeric human P-selectin to immobilized PSGL-1 from human neutrophils. Binding was specific, as documented by its Ca2+-dependence, its inhibition by specific monoclonal antibodies to P-selectin and PSGL-1, and its abrogation by treating PSGL-1 with sialidase. Similar binding was observed for soluble P-selectin that contained the lectin and epidermal growth factor domains plus all nine consensus repeats, and for a soluble construct that contained only the lectin and epidermal growth factor domains. Soluble P-selectin bound saturably to a single class of sites on PSGL-1 with a dissociation constant (Kd) of 320 +/- 20 nM. The measured koff was 1.4 +/- 0.1 s-1, and the calculated kon was 4.4 x 10(6) M-1 s-1. We conclude that monomeric P-selectin binds to PSGL-1 with fast association and dissociation rates and relatively high affinity. These features may be important for efficient tethering and rolling of leukocytes at physiologic densities of PSGL-1 and P-selectin.
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Affiliation(s)
- P Mehta
- W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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40
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Granger HJ. Cardiovascular physiology in the twentieth century: great strides and missed opportunities. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:H1925-36. [PMID: 9843790 DOI: 10.1152/ajpheart.1998.275.6.h1925] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In a broad sense, physiology is the study of the chemical and physical bases of life processes. Consequently, the evolution of our knowledge of cardiovascular functions is closely linked to the developments in many fields of science, including chemistry, physics, engineering, and biology. A cursory examination reveals that different "foundation" sciences predominated in different stages of the history of cardiovascular physiology. Today, cardiovascular physiology is poised to exploit new developments in all areas of scientific inquiry. However, cardiovascular physiologists have not always embraced the power of the multidisciplinary approach. In this brief overview of the history of cardiovascular physiology in the 20th century, the major focus is on some of the major advances in the field and the contributions of other disciplines to these developments. In addition, the forces that influenced cardiovascular science in this century and their impact on the evolution of the field in the new millennium are discussed.
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Affiliation(s)
- H J Granger
- Cardiovascular Research Institute and Department of Medical Physiology, College of Medicine, Texas 77843-1114, USA
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Hartwell DW, Mayadas TN, Berger G, Frenette PS, Rayburn H, Hynes RO, Wagner DD. Role of P-selectin cytoplasmic domain in granular targeting in vivo and in early inflammatory responses. J Cell Biol 1998; 143:1129-41. [PMID: 9817767 PMCID: PMC2132959 DOI: 10.1083/jcb.143.4.1129] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1998] [Revised: 09/10/1998] [Indexed: 02/02/2023] Open
Abstract
P-selectin is an adhesion receptor for leukocytes expressed on activated platelets and endothelial cells. The cytoplasmic domain of P-selectin was shown in vitro to contain signals required for both the sorting of this protein into storage granules and its internalization from the plasma membrane. To evaluate in vivo the role of the regulated secretion of P-selectin, we have generated a mouse that expresses P-selectin lacking the cytoplasmic domain (DeltaCT mice). The deletion did not affect the sorting of P-selectin into alpha-granules of platelets but severely compromised the storage of P-selectin in endothelial cells. Unstored P-selectin was proteolytically shed from the plasma membrane, resulting in increased levels of soluble P-selectin in the plasma. The DeltaCT-P-selectin appeared capable of mediating cell adhesion as it supported leukocyte rolling in the mutant mice. However, a secretagogue failed to upregulate leukocyte rolling in the DeltaCT mice, indicating an absence of a releasable storage pool of P-selectin in the endothelium. Furthermore, the neutrophil influx into the inflamed peritoneum was only 30% of the wild-type level 2 h after stimulation. Our results suggest that different sorting mechanisms for P-selectin are used in platelets and endothelial cells and that the storage pool of P-selectin in endothelial cells is functionally important during early stages of inflammation.
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Affiliation(s)
- D W Hartwell
- Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA
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Chesla SE, Selvaraj P, Zhu C. Measuring two-dimensional receptor-ligand binding kinetics by micropipette. Biophys J 1998; 75:1553-72. [PMID: 9726957 PMCID: PMC1299830 DOI: 10.1016/s0006-3495(98)74074-3] [Citation(s) in RCA: 304] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report a novel method for measuring forward and reverse kinetic rate constants, kf0 and kr0, for the binding of individual receptors and ligands anchored to apposing surfaces in cell adhesion. Not only does the method examine adhesion between a single pair of cells; it also probes predominantly a single receptor-ligand bond. The idea is to quantify the dependence of adhesion probability on contact duration and densities of the receptors and ligands. The experiment was an extension of existing micropipette protocols. The analysis was based on analytical solutions to the probabilistic formulation of kinetics for small systems. This method was applied to examine the interaction between Fc gamma receptor IIIA (CD16A) expressed on Chinese hamster ovary cell transfectants and immunoglobulin G (IgG) of either human or rabbit origin coated on human erythrocytes, which were found to follow a monovalent biomolecular binding mechanism. The measured rate constants are Ackf0 = (2.6 +/- 0.32) x 10(-7) micron 4 s-1 and kr0 = (0.37 +/- 0.055) s-1 for the CD16A-hIgG interaction and Ackf0 = (5.7 +/- 0.31) X 10(-7) micron 4 s-1 and kr0 = (0.20 +/- 0.042) s-1 for the CD16A-rIgG interaction, respectively, where Ac is the contact area, estimated to be a few percent of 3 micron 2.
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Affiliation(s)
- S E Chesla
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta 30332-0405, USA
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