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Beat A Imhof - One of the best experts on this subject based on the ideXlab platform.
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Junctional Adhesion Molecule c mediates the recruitment of embryonic endothelial progenitor cells to the perivascular niche during tumor angiogenesis
International Journal of Molecular Sciences, 2020Co-Authors: Maria Vinci, Beat A Imhof, Marcus Czabanka, Lucia Lisa Petrilli, Susanne Elvershornung, Karen Bieback, Peter VajkoczyAbstract:: The homing of Endothelial Progenitor Cells (EPCs) to tumor angiogenic sites has been described as a multistep process, involving Adhesion, migration, incorporation and sprouting, for which the underlying molecular and cellular mechanisms are yet to be fully defined. Here, we studied the expression of Junctional Adhesion Molecule-C (JAM-C) by EPCs and its role in EPC homing to tumor angiogenic vessels. For this, we used mouse embryonic-Endothelial Progenitor Cells (e-EPCs), intravital multi-fluorescence microscopy techniques and the dorsal skin-fold chamber model. JAM-C was found to be expressed by e-EPCs and endothelial cells. Blocking JAM-C did not affect Adhesion of e-EPCs to endothelial monolayers in vitro but, interestingly, it did reduce their Adhesion to tumor endothelium in vivo. The most striking effect of JAM-C blocking was on tube formation on matrigel in vitro and the incorporation and sprouting of e-EPCs to tumor endothelium in vivo. Our results demonstrate that JAM-C mediates e-EPC recruitment to tumor angiogenic sites, i.e., coordinated homing of EPCs to the perivascular niche, where they cluster and interact with tumor blood vessels. This suggests that JAM-C plays a critical role in the process of vascular assembly and may represent a potential therapeutic target to control tumor angiogenesis.
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Junctional Adhesion Molecule C (JAM-C) dimerization aids cancer cell migration and metastasis
Biochimica et Biophysica Acta - Molecular Cell Research, 2018Co-Authors: Sarah Garrido-urbani, Florence Bardin, Patricia Ropraz, Alain Vonlaufen, Jimmy Stalin, Maria De Grandis, Stephane Jemelin, Holger Scheib, Michel Aurrand-lions, Beat A ImhofAbstract:Most cancer deaths result from metastasis, which is the dissemination of cells from a primary tumor to distant organs. Metastasis involves changes to Molecules that are essential for tumor cell Adhesion to the extracellular matrix and to endothelial cells. Junctional Adhesion Molecule C (JAM-C) localizes at intercellular junctions as homodimers or more affine heterodimers with JAM-B. We previously showed that the homodimerization site (E66) in JAM-C is also involved in JAM-B binding. Here we show that neoexpression of JAM-C in a JAM-C negative carcinoma cell line induced loss of adhesive property and pro-metastatic capacities. We also identify two critical structural sites (E66 and K68) for JAM-C/JAM-B interaction by directed mutagenesis of JAM-C and studied their implication on tumor cell behavior. JAM-C mutants did not bind to JAM-B or localize correctly to junctions. Moreover, mutated JAM-C proteins increased Adhesion and reduced proliferation and migration of lung carcinoma cell lines. Carcinoma cells expressing mutant JAM-C grew slower than with JAM-C WT and were not able to establish metastatic lung nodules in mice. Overall these data demonstrate that the dimerization sites E66-K68 of JAM-C affected cell Adhesion, polarization and migration and are essential for tumor cell metastasis.
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Junctional Adhesion Molecule C Mediates Leukocyte Adhesion to Rheumatoid Arthritis Synovium
2016Co-Authors: Kenneth G Haines, Beat A Imhof, Alisa E KochAbstract:Objective. Leukocyte infiltration into the rheuma-toid arthritis (RA) synovium is a multistep process in which leukocytes leave the bloodstream and invade the synovial tissue (ST). Leukocyte transendothelial migra-tion and Adhesion to RA ST requires Adhesion mole-cules on the surface of endothelial cells and RA ST fibroblasts. This study was undertaken to investigate the role of Junctional Adhesion Molecule C (JAM-C) in mediating leukocyte recruitment and retention in the RA joint. Methods. Immunohistologic analysis was per-formed on RA, osteoarthritis (OA), and normal ST samples to quantify JAM-C expression. Fibroblast JAM-C expression was also analyzed using Western blotting, cell surface enzyme-linked immunosorbent as-say, and immunofluorescence. To determine the role of JAM-C in leukocyte retention in the RA synovium, in vitro and in situ Adhesion assays and RA ST fibroblast transmigration assays were performed. Results. JAM-C was highly expressed by RA ST lining cells, and its expression was increased in OA ST and RA ST endothelial cells compared with normal ST endothelial cells. JAM-C was also expressed on the surface of OA ST and RA ST fibroblasts. Furthermore, we demonstrated that myeloid U937 cell Adhesion t
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Blockade but Not Overexpression of the Junctional Adhesion Molecule C Influences Virus-Induced Type 1 Diabetes in Mice
2016Co-Authors: Selina Christen, Beat A Imhof, Michel Aurr, Kerstin Rose, Martin Holdener, Monika Bayer, Josef M. Pfeilschifter, Edith Hintermann, Matthias G. Von Herrath, Urs ChristenAbstract:Type 1 diabetes (T1D) results from the autoimmune destruction of insulin-producing beta-cells in the pancreas. Recruitment of inflammatory cells is prerequisite to beta-cell-injury. The Junctional Adhesion Molecule (JAM) family proteins JAM-B and JAM–C are involved in polarized leukocyte transendothelial migration and are expressed by vascular endothelial cells of peripheral tissue and high endothelial venules in lympoid organs. Blocking of JAM-C efficiently attenuated cerulean-induced pancreatitis, rheumatoid arthritis or inflammation induced by ischemia and reperfusion in mice. In order to investigate the influence of JAM-C on trafficking and transmigration of antigen-specific, autoaggressive T-cells, we used transgenic mice that express a protein of the lymphocytic choriomeningitis virus (LCMV) as a target autoantigen in the b-cells of the islets of Langerhans under the rat insulin promoter (RIP). Such RIP-LCMV mice turn diabetic after infection with LCMV. We found that upon LCMV-infection JAM-C protein was upregulated around the islets in RIP-LCMV mice. JAM-C expression correlated with islet infiltration and functional beta-cell impairment. Blockade with a neutralizing anti-JAM-C antibody reduced the T1D incidence. However, JAM-C overexpression on endothelial cells did not accelerate diabetes in the RIP-LCMV model. In summary, our data suggest that JAM-C might be involved in the final steps of trafficking and transmigration of antigen
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Junctional Adhesion Molecule (JAM)-C Deficient C57BL/6 Mice Develop a Severe Hydrocephalus
2016Co-Authors: Lena Wyss, Ralf H Adams, Beat A Imhof, Stefan Liebner, Michel Mittelbronn, Urban Deutsch, Gaby Enzmann, Michel Aurr, Karl H. Plate, Britta EngelhardtAbstract:The Junctional Adhesion Molecule (JAM)-C is a widely expressed Adhesion Molecule regulating cell Adhesion, cell polarity and inflammation. JAM-C expression and function in the central nervous system (CNS) has been poorly characterized to date. Here we show that JAM-C2/2 mice backcrossed onto the C57BL/6 genetic background developed a severe hydrocephalus. An in depth immunohistochemical study revealed specific immunostaining for JAM-C in vascular endothelial cells in the CNS parenchyma, the meninges and in the choroid plexus of healthy C57BL/6 mice. Additional JAM-C immunostaining was detected on ependymal cells lining the ventricles and on choroid plexus epithelial cells. Despite the presence of hemorrhages in the brains of JAM-C2/2 mice, our study demonstrates that development of the hydrocephalus was not due to a vascular function of JAM-C as endothelial re-expression of JAM-C failed to rescue the hydrocephalus phenotype of JAM-C2/2 C57BL/6 mice. Evaluation of cerebrospinal fluid (CSF) circulation within the ventricular system of JAM-C2/2 mice excluded occlusion of the cerebral aqueduct as the cause of hydrocephalus development but showed the acquisition of a block or reduction of CSF drainage from the lateral to the 3rd ventricle in JAM-C2/2 C57BL/6 mice. Taken together, our study suggests that JAM-C2/2 C57BL/6 mice model the important role for JAM-C in brain development an
Thilo Stehle - One of the best experts on this subject based on the ideXlab platform.
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structure of serotype 1 reovirus attachment protein σ1 in complex with Junctional Adhesion Molecule a reveals a conserved serotype independent binding epitope
Journal of Virology, 2015Co-Authors: Eva Stettner, Terence S. Dermody, Thilo Stehle, Melanie H Dietrich, Kerstin ReissAbstract:Mammalian orthoreoviruses use glycans and Junctional Adhesion Molecule A (JAM-A) as attachment receptors. We determined the structure of serotype 1 reovirus attachment protein σ1 alone and in complex with JAM-A. Comparison with the structure of serotype 3 reovirus σ1 bound to JAM-A reveals that both σ1 proteins engage JAM-A with similar affinities and via conserved binding epitopes. Thus, σ1–JAM-A interactions are unlikely to explain the differences in pathogenesis displayed by these reovirus serotypes.
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structure of reovirus σ1 in complex with its receptor Junctional Adhesion Molecule a
PLOS Pathogens, 2008Co-Authors: Eva Kirchner, Terence S. Dermody, Kristen M Guglielmi, Thilo Stehle, Holger M StraussAbstract:Viral attachment to specific host receptors is the first step in viral infection and serves an essential function in the selection of target cells. Mammalian reoviruses are highly useful experimental models for studies of viral pathogenesis and show promise as vectors for oncolytics and vaccines. Reoviruses engage cells by binding to carbohydrates and the immunoglobulin superfamily member, Junctional Adhesion Molecule-A (JAM-A). JAM-A exists at the cell surface as a homodimer formed by extensive contacts between its N-terminal immunoglobulin-like domains. We report the crystal structure of reovirus attachment protein σ1 in complex with a soluble form of JAM-A. The σ1 protein disrupts the JAM-A dimer, engaging a single JAM-A Molecule via virtually the same interface that is used for JAM-A homodimerization. Thus, reovirus takes advantage of the adhesive nature of an immunoglobulin-superfamily receptor by usurping the ligand-binding site of this Molecule to attach to the cell surface. The dissociation constant (KD) of the interaction between σ1 and JAM-A is 1,000-fold lower than that of the homophilic interaction between JAM-A Molecules, indicating that JAM-A strongly prefers σ1 as a ligand. Analysis of reovirus mutants engineered by plasmid-based reverse genetics revealed residues in σ1 required for binding to JAM-A and infectivity of cultured cells. These studies define biophysical mechanisms of reovirus cell attachment and provide a platform for manipulating reovirus tropism to enhance vector targeting.
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reovirus binding determinants in Junctional Adhesion Molecule a
Journal of Biological Chemistry, 2007Co-Authors: Kristen M Guglielmi, Eva Kirchner, Geoffrey H Holm, Thilo Stehle, Terence S. DermodyAbstract:Junctional Adhesion Molecule-A (JAM-A) serves as a serotype-independent receptor for mammalian orthoreoviruses (reoviruses). The membrane-distal immunoglobulin-like D1 domain of JAM-A is required for homodimerization and binding to reovirus attachment protein σ1. We employed a structure-guided mutational analysis of the JAM-A dimer interface to identify determinants of reovirus binding. We purified mutant JAM-A ectodomains for solution-phase and surface plasmon resonance binding studies and expressed mutant forms of full-length JAM-A in Chinese hamster ovary cells to assess reovirus binding and infectivity. Mutation of residues in the JAM-A dimer interface that participate in salt-bridge or hydrogen-bond interactions with apposing JAM-A monomers abolishes the capacity of JAM-A to form dimers. JAM-A mutants incapable of dimer formation form complexes with the σ1 head that are indistinguishable from wild-type JAM-A-σ1 head complexes, indicating that σ1 binds to JAM-A monomers. Residues Glu61 and Lys63 of β-strand C and Leu72 of β-strand C′ in the dimer interface are required for efficient JAM-A engagement of strain type 3 Dearing σ1. Mutation of neighboring residues alters the kinetics of the σ1-JAM-A binding interaction. Prototype reovirus strains type 1 Lang and type 2 Jones share similar, although not identical, binding requirements with type 3 Dearing. These results indicate that reovirus engages JAM-A monomers via residues found mainly on β-strands C and C′ of the dimer interface and raise the possibility that the distinct disease phenotypes produced in mice following infection with different strains of reovirus are in part attributable to differences in contacts with JAM-A.
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a chimeric adenovirus vector encoding reovirus attachment protein σ1 targets cells expressing Junctional Adhesion Molecule 1
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: George T Mercier, Terence S. Dermody, Jacquelyn A. Campbell, Thilo Stehle, James D Chappell, Michael A BarryAbstract:The utility of adenovirus (Ad) vectors for gene transduction can be limited by receptor specificity. We developed a gene-delivery vehicle in which the potent Ad5 vector was genetically reengineered to display the mucosal-targeting σ1 protein of reovirus type 3 Dearing (T3D). A σ1 construct containing all but a small virion-anchoring domain was fused to the N-terminal 44 aa of Ad5 fiber. This chimeric attachment protein Fibtail-T3Dσ1 forms trimers and assembles onto Ad virions. Fibtail-T3Dσ1 was recombined into the Ad5 genome, replacing sequences encoding wild-type fiber. The resulting vector, Ad5-T3Dσ1, expresses Fibtail-T3Dσ1 and infects Chinese hamster ovary cells transfected with human or mouse homologs of the reovirus receptor, Junctional Adhesion Molecule 1 (JAM1), but not the coxsackievirus and Ad receptor. Treatment of Caco-2 intestinal epithelial cells with either JAM1-specific antibody or neuraminidase reduced transduction by Ad5-T3Dσ1, and their combined effect decreased transduction by 95%. Ad5-T3Dσ1 transduces primary cultures of human dendritic cells substantially more efficiently than does Ad5, and this transduction depends on expression of JAM1. These data provide strong evidence that Ad5-T3Dσ1 can be redirected to cells expressing JAM1 and sialic acid for application as a vaccine vector.
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structure function analysis of reovirus binding to Junctional Adhesion Molecule 1 implications for the mechanism of reovirus attachment
Journal of Biological Chemistry, 2003Co-Authors: Craig J Forrest, Thilo Stehle, Jacquelyn A. Campbell, Pierre Schelling, Terence S. DermodyAbstract:Abstract Mammalian reoviruses are nonenveloped viruses with a long, filamentous attachment protein that dictates disease phenotypes following infection of newborn mice and is a structural homologue of the adenovirus attachment protein. Reoviruses use Junctional Adhesion Molecule 1 (JAM1) as a serotype-independent cellular receptor. JAM1 is a broadly expressed immunoglobulin superfamily protein that forms stable homodimers and regulates tight-junction permeability and lymphocyte trafficking. We employed a series of structure-guided binding and infection experiments to define residues in human JAM1 (hJAM1) important for reovirus-receptor interactions and to gain insight into mechanisms of reovirus attachment. Binding and infection experiments using chimeric and domain deletion mutant receptor Molecules indicate that the amino-terminal D1 domain of hJAM1 is required for reovirus attachment, infection, and replication. Reovirus binding to hJAM1 occurs more rapidly than homotypic hJAM1 association and is competed by excess hJAM1 in vitro and on cells. Cross-linking hJAM1 diminishes the capacity of reovirus to bind hJAM1 in vitro and on cells and negates the competitive effects of soluble hJAM1 on reovirus attachment. Finally, mutagenesis studies demonstrate that residues intimately associated with the hJAM1 dimer interface are critical for reovirus interactions with hJAM1. These results suggest that reovirus attachment disrupts hJAM1 dimers and highlight similarities between the attachment strategies of reovirus and adenovirus.
Elisabetta Dejana - One of the best experts on this subject based on the ideXlab platform.
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Rapid Communication Importance of Junctional Adhesion Molecule-A for Neointimal Lesion Formation and Infiltration in Atherosclerosis-Prone Mice
2016Co-Authors: Alma Zernecke, Monica Corada, Elisabetta Dejana, Rory R Koenen, Line Fraemohs, Elisa A Liehn, Christian WeberAbstract:Objective—Although Junctional Adhesion Molecule-A (JAM-A) has recently been implicated in leukocyte recruitment on early atherosclerotic endothelium and after reperfusion injury, its role in neointima formation after arterial injury remains to be elucidated. Methods and Results—Here we show that the genetic deletion of JAM-A in apolipoprotein E–deficient (apoE/) mice significantly reduced neointimal hyperplasia after wire injury of carotid arteries without altering medial area. This was associated with a significant decrease in neointimal macrophage content, whereas the relative content of smooth muscle cells and endothelial recovery was unaltered in JAM-A/apoE/ compared with JAM-A/apoE/ lesions. In carotid arteries perfused ex vivo, deficiency in JAM-A significantly impaired the recruitment of monocytes 1 week, but not 1 day, after injury. These effects were paralleled by an attenuation of monocyte arrest and transmigration on activated JAM-A/apoE/ versus JAM-A/apoE/ endothelial cells under flow conditions in vitro. A mechanism underlying reduced recruitment was implied by findings that the luminal expression of the arrest chemokine RANTES in injured arteries and its endothelial deposition by activated platelets in vitro were diminished by JAM-A deficiency. Conclusions—Our data provide the first evidence to our knowledge for a crucial role of JAM-A in accelerated lesion formation and monocyte infiltration in atherosclerosis-prone mice. (Arterioscler Thromb Vasc Biol. 2006;26:e10-e13.) Key Words: Adhesion Molecule atherosclerosis chemokine monocytes Junctional Adhesion Molecule-A (JAM-A), a member of theIgG superfamily, has been identified to participate in th
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importance of Junctional Adhesion Molecule a for neointimal lesion formation and infiltration in atherosclerosis prone mice
Arteriosclerosis Thrombosis and Vascular Biology, 2005Co-Authors: Alma Zernecke, Monica Corada, Elisabetta Dejana, Rory R Koenen, Line Fraemohs, Elisa A Liehn, Philipp Von Hundelshausen, Christian WeberAbstract:Objective— Although Junctional Adhesion Molecule-A (JAM-A) has recently been implicated in leukocyte recruitment on early atherosclerotic endothelium and after reperfusion injury, its role in neointima formation after arterial injury remains to be elucidated. Methods and Results— Here we show that the genetic deletion of JAM-A in apolipoprotein E–deficient (apoE −/− ) mice significantly reduced neointimal hyperplasia after wire injury of carotid arteries without altering medial area. This was associated with a significant decrease in neointimal macrophage content, whereas the relative content of smooth muscle cells and endothelial recovery was unaltered in JAM-A −/− apoE −/− compared with JAM-A +/+ apoE −/− lesions. In carotid arteries perfused ex vivo, deficiency in JAM-A significantly impaired the recruitment of monocytes 1 week, but not 1 day, after injury. These effects were paralleled by an attenuation of monocyte arrest and transmigration on activated JAM-A −/− apoE −/− versus JAM-A +/+ apoE −/− endothelial cells under flow conditions in vitro. A mechanism underlying reduced recruitment was implied by findings that the luminal expression of the arrest chemokine RANTES in injured arteries and its endothelial deposition by activated platelets in vitro were diminished by JAM-A deficiency. Conclusions— Our data provide the first evidence to our knowledge for a crucial role of JAM-A in accelerated lesion formation and monocyte infiltration in atherosclerosis-prone mice.
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Junctional Adhesion Molecule a deficiency increases hepatic ischemia reperfusion injury despite reduction of neutrophil transendothelial migration
Blood, 2005Co-Authors: Andrej Khandoga, Monica Corada, Elisabetta Dejana, Toshiyuki Motoike, Julia S Kessler, Herbert Meissner, Marc Hanschen, Georg Enders, Fritz KrombachAbstract:The endothelial receptors that control leukocyte transmigration in the postischemic liver are not identified. We investigated the role of Junctional Adhesion Molecule-A (JAM-A), a receptor expressed in endothelial tight junctions, leukocytes, and platelets, for leukocyte transmigration during hepatic ischemia-reperfusion (I/R) in vivo. We show that JAM-A is up-regulated in hepatic venular endothelium during reperfusion. I/R-induced neutrophil transmigration was attenuated in both JAM-A-/- and endothelial JAM-A-/- mice as well as in mice treated with an anti-JAM-A antibody, whereas transmigration of T cells was JAM-A independent. Postischemic leukocyte rolling remained unaffected in JAM-A-/- and endothelial JAM-A-/- mice, whereas intravascular leukocyte adherence was increased. The extent of interactions of JAM-A-/- platelets with the postischemic endothelium was comparable with that of JAM-A+/+ platelets. The I/R-induced increase in the activity of alanine aminotransferase (ALT)/aspartate aminotransferase (AST) and sinusoidal perfusion failure was not reduced in JAM-A-/- mice, while the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive hepatocytes was significantly higher. Thus, we show for the first time that JAM-A is up-regulated in hepatic venules and serves as an endothelial receptor of neutrophil transmigration, but it does not mediate leukocyte rolling, Adhesion, or platelet-endothelial cell interactions. JAM-A deficiency does not reduce I/R-induced microvascular and hepatocellular necrotic injury, but increases hepatocyte apoptosis, despite attenuation of neutrophil infiltration. (Blood. 2005;106:725-733)
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expression of Junctional Adhesion Molecule a prevents spontaneous and random motility
Journal of Cell Science, 2005Co-Authors: Gianfranco Bazzoni, Maria Rosaria Cera, Elisabetta Dejana, Paolo Tonetti, Luca Manzi, G BalconiAbstract:Junctional Adhesion Molecule-A (JAM-A) is a cell-surface glycoprotein that localizes to intercellular junctions and associates with intracellular proteins via PSD95-Dlg-ZO1-binding residues. To define the functional consequences of JAM-A expression, we have produced endothelial cells from JAM-A-deficient mice. We report here that the absence of JAM-A enhanced spontaneous and random motility. In turn, the enhanced motility of JAM-A-negative cells was abrogated either on transfection of exogenous JAM-A or on treatment with inhibitors of glycogen synthase kinase-3β (GSK-3β). In addition, in JAM-A-positive cells, motility was enhanced on inactivation of protein kinase Cζ (PKCζ), which is an inhibitor of GSK-3β. Although these findings suggested that JAM-A might inhibit GSK-3β, we found that expression per se of JAM-A did not change the levels of inactive GSK-3β. Thus, JAM-A expression may regulate effectors of motility that are also downstream of the PKCζ/GSK-3β axis. In support of this view, we found that JAM-A absence increased the number of actin-containing protrusions, reduced the stability of microtubules and impaired the formation of focal Adhesions. Notably, all the functional consequences of JAM-A absence were reversed either on treatment with GSK-3β inhibitors or on transfection of full-length JAM-A, but not on transfection of a JAM-A deletion mutant devoid of the PSD95-Dlg-ZO1-binding residues. Thus, by regulating cytoskeletal and adhesive structures, JAM-A expression prevents cell motility, probably in a PSD95-Dlg-ZO1-dependent manner.
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association of Junctional Adhesion Molecule with calcium calmodulin dependent serine protein kinase cask lin 2 in human epithelial caco 2 cells
Journal of Biological Chemistry, 2001Co-Authors: Ofelia Maria Martinezestrada, Antonello Villa, Elisabetta Dejana, Fabrizio Orsenigo, Ferruccio Breviario, Gianfranco BazzoniAbstract:We report here that Junctional Adhesion Molecule (JAM) interacts with calcium/calmodulin-dependent serine protein kinase (CASK), a protein related to membrane-associated guanylate kinases. In Caco-2 cells, JAM and CASK were coprecipitated and found to colocalize at intercellular contacts along the lateral surface of the plasma membrane. Association of JAM with CASK requires the PSD95/dlg/ZO-1 (PDZ) domain of CASK and the putative PDZ-binding motif Phe-Leu-Val(COOH) in the cytoplasmic tail of JAM. Temporal dissociation in the Junctional localization of the two proteins suggests that the association with CASK is not required for recruiting JAM to intercellular junctions. Compared with mature intercellular contacts, junction assembly was characterized by both enhanced solubility of CASK in Triton X-100 and reduced amounts of Triton-insoluble JAM-CASK complexes. We propose that JAM association with CASK is modulated during junction assembly, when CASK is partially released from its cytoskeletal associations.
Michel Aurrandlions - One of the best experts on this subject based on the ideXlab platform.
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Junctional Adhesion Molecule b interferes with angiogenic vegf vegfr2 signaling
The FASEB Journal, 2015Co-Authors: Mehdi Meguenani, Ralf H Adams, Michel Aurrandlions, Beat A Imhof, Marijana Miljkoviclicina, Ernesta Fagiani, Patricia Ropraz, Philippe Hammel, Gerhard Christofori, Sarah GarridourbaniAbstract:De novo formation of blood vessels is a pivotal mechanism during cancer development. During the past few years, antiangiogenic drugs have been developed to target tumor vasculature. However, because of limitations and adverse effects observed with current therapies, there is a strong need for alternative antiangiogenic strategies. Using specific anti-Junctional Adhesion Molecule (JAM)-B antibodies and Jam-b-deficient mice, we studied the role in antiangiogenesis of JAM-B. We found that antibodies against murine JAM-B, an endothelium-specific Adhesion Molecule, inhibited microvessel outgrowth from ex vivo aortic rings and in vitro endothelial network formation. In addition, anti-JAM-B antibodies blocked VEGF signaling, an essential pathway for angiogenesis. Moreover, increased aortic ring branching was observed in aortas isolated from Jam-b-deficient animals, suggesting that JAM-B negatively regulates proangiogenic pathways. In mice, JAM-B expression was detected in de novo-formed blood vessels of tumors, but anti-JAM-B antibodies unexpectedly did not reduce tumor growth. Accordingly, JAM-B deficiency in vivo had no impact on blood vessel formation, suggesting that targeting JAM-B in vivo may be offset by other proangiogenic mechanisms. In conclusion, despite the promising effects observed in vitro, targeting JAM-B during tumor progression seems to be inefficient as a stand-alone antiangiogenesis therapy.
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Junctional Adhesion Molecule jam c deficient c57bl 6 mice develop a severe hydrocephalus
PLOS ONE, 2012Co-Authors: Lena Wyss, Ralf H Adams, Michel Aurrandlions, Stefan Liebner, Michel Mittelbronn, Urban Deutsch, Gaby Enzmann, Julia Schafer, Karl H. PlateAbstract:The Junctional Adhesion Molecule (JAM)-C is a widely expressed Adhesion Molecule regulating cell Adhesion, cell polarity and inflammation. JAM-C expression and function in the central nervous system (CNS) has been poorly characterized to date. Here we show that JAM-C(-/-) mice backcrossed onto the C57BL/6 genetic background developed a severe hydrocephalus. An in depth immunohistochemical study revealed specific immunostaining for JAM-C in vascular endothelial cells in the CNS parenchyma, the meninges and in the choroid plexus of healthy C57BL/6 mice. Additional JAM-C immunostaining was detected on ependymal cells lining the ventricles and on choroid plexus epithelial cells. Despite the presence of hemorrhages in the brains of JAM-C(-/-) mice, our study demonstrates that development of the hydrocephalus was not due to a vascular function of JAM-C as endothelial re-expression of JAM-C failed to rescue the hydrocephalus phenotype of JAM-C(-/-) C57BL/6 mice. Evaluation of cerebrospinal fluid (CSF) circulation within the ventricular system of JAM-C(-/-) mice excluded occlusion of the cerebral aqueduct as the cause of hydrocephalus development but showed the acquisition of a block or reduction of CSF drainage from the lateral to the 3(rd) ventricle in JAM-C(-/-) C57BL/6 mice. Taken together, our study suggests that JAM-C(-/-) C57BL/6 mice model the important role for JAM-C in brain development and CSF homeostasis as recently observed in humans with a loss-of-function mutation in JAM-C.
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Junctional Adhesion Molecule c mediates leukocyte infiltration in response to ischemia reperfusion injury
Arteriosclerosis Thrombosis and Vascular Biology, 2009Co-Authors: Christoph Scheiermann, Abigail Woodfin, Mathieubenoit Voisin, Bartomeu Colom, Paolo Meda, Nimesh S A Patel, Alessandra Marrelli, Costantino Pitzalis, Christoph Thiemermann, Michel AurrandlionsAbstract:Objective— Junctional Adhesion Molecule-C (JAM-C) is an Adhesion Molecule that has multiple roles in inflammation and vascular biology, but many aspects of its functions under pathological conditions are unknown. Here we investigated the role of JAM-C in leukocyte migration in response to ischemia reperfusion (I/R) injury. Methods and Results— Pretreatment of mice with soluble JAM-C (sJAM-C), used as a pharmacological blocker of JAM-C-mediated reactions, significantly suppressed leukocyte migration in models of kidney and cremaster muscle I/R injury (39 and 51% inhibition, respectively). Furthermore, in the cremaster muscle model (studied by intravital microscopy), both leukocyte Adhesion and transmigration were suppressed in JAM-C-deficient mice (JAM-C −/− ) and enhanced in mice overexpressing JAM-C in their endothelial cells (ECs). Analysis of JAM-C subcellular expression by immunoelectron microscopy indicated that in I/R-injured tissues, EC JAM-C was redistributed from cytoplasmic vesicles and EC Junctional sites to nonJunctional plasma membranes, a response that may account for the role of JAM-C in both leukocyte Adhesion and transmigration under conditions of I/R injury. Conclusions— The findings demonstrate a role for EC JAM-C in mediating leukocyte Adhesion and transmigration in response to I/R injury and indicate the existence of a novel regulatory mechanism for redistribution and hence function of EC JAM-C in vivo.
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expression and function of Junctional Adhesion Molecule c in human and experimental arthritis
Arthritis Research & Therapy, 2007Co-Authors: Gaby Palmer, Michel Aurrandlions, Beat A Imhof, Philippe Hammel, Nathalie Busso, Dominique Talabotayer, Veronique Chobazpeclat, Claudia Zimmerli, Cem GabayAbstract:Junctional Adhesion Molecule-C (JAM-C) is an Adhesion Molecule involved in transendothelial migration of leukocytes. In this study, we examined JAM-C expression in the synovium and investigated the role of this Molecule in two experimental mouse models of arthritis. JAM-C expression was investigated by reverse transcriptase-polymerase chain reaction and immunohistochemistry. The effects of a monoclonal anti-JAM-C antibody were assessed in antigen-induced arthritis (AIA) and K/BxN serum transfer-induced arthritis. JAM-C was expressed by synovial fibroblasts in the lining layer and associated with vessels in the sublining layer in human and mouse arthritic synovial tissue. In human tissue, JAM-C expression was increased in rheumatoid arthritis (RA) as compared to osteoarthritis synovial samples (12.7 ± 1.3 arbitrary units in RA versus 3.3 ± 1.1 in OA; p < 0.05). Treatment of mice with a monoclonal anti-JAM-C antibody decreased the severity of AIA. Neutrophil infiltration into inflamed joints was selectively reduced as compared to T-lymphocyte and macrophage infiltration (0.8 ± 0.3 arbitrary units in anti-JAM-C-treated versus 2.3 ± 0.6 in isotype-matched control antibody-treated mice; p < 0.05). Circulating levels of the acute-phase protein serum amyloid A as well as antigen-specific and concanavalin A-induced spleen T-cell responses were significantly decreased in anti-JAM-C antibody-treated mice. In the serum transfer-induced arthritis model, treatment with the anti-JAM-C antibody delayed the onset of arthritis. JAM-C is highly expressed by synovial fibroblasts in RA. Treatment of mice with an anti-JAM-C antibody significantly reduced the severity of AIA and delayed the onset of serum transfer-induced arthritis, suggesting a role for JAM-C in the pathogenesis of arthritis.
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antibody against Junctional Adhesion Molecule c inhibits angiogenesis and tumor growth
Cancer Research, 2005Co-Authors: Chrystelle Lamagna, Beat A Imhof, Kairbaan Hodivaladilke, Michel AurrandlionsAbstract:The Junctional Adhesion Molecule-C (JAM-C) was recently described as an Adhesion Molecule localized at interendothelial contacts and involved in leukocyte transendothelial migration. The protein JAM-C interacts with polarity complex Molecules and regulates the activity of the small GTPase Cdc42. The angiogenesis process involves rearrangement of endothelial junctions and implicates modulation of cell polarity. We tested whether JAM-C plays a role in angiogenesis using tumor grafts and hypoxia-induced retinal neovascularization. Treatment with a monoclonal antibody directed against JAM-C reduces tumor growth and infiltration of macrophages into tumors. The antibody decreases angiogenesis in the model of hypoxia-induced retinal neovascularization in vivo and vessel outgrowth from aortic rings in vitro. Importantly, the antibody does not induce pathologic side effects in vivo. These findings show for the first time a role for JAM-C in angiogenesis and define JAM-C as a valuable target for antitumor therapies.
Terence S. Dermody - One of the best experts on this subject based on the ideXlab platform.
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structure of serotype 1 reovirus attachment protein σ1 in complex with Junctional Adhesion Molecule a reveals a conserved serotype independent binding epitope
Journal of Virology, 2015Co-Authors: Eva Stettner, Terence S. Dermody, Thilo Stehle, Melanie H Dietrich, Kerstin ReissAbstract:Mammalian orthoreoviruses use glycans and Junctional Adhesion Molecule A (JAM-A) as attachment receptors. We determined the structure of serotype 1 reovirus attachment protein σ1 alone and in complex with JAM-A. Comparison with the structure of serotype 3 reovirus σ1 bound to JAM-A reveals that both σ1 proteins engage JAM-A with similar affinities and via conserved binding epitopes. Thus, σ1–JAM-A interactions are unlikely to explain the differences in pathogenesis displayed by these reovirus serotypes.
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Junctional Adhesion Molecule-A Is Required for Hematogenous Dissemination of Reovirus
Cell host & microbe, 2009Co-Authors: Annukka A.r. Antar, Jennifer L. Konopka, Jacquelyn A. Campbell, Rachel A. Henry, Ana L. Perdigoto, Bruce D. Carter, Ambra Pozzi, Ty W. Abel, Terence S. DermodyAbstract:Summary Diverse families of viruses bind immunoglobulin superfamily (IgSF) proteins located in tight junctions (TJs) and adherens junctions of epithelium and endothelium. However, little is known about the roles of these receptors in the pathogenesis of viral disease. Junctional Adhesion Molecule-A (JAM-A) is an IgSF protein that localizes to TJs and serves as a receptor for mammalian reovirus. We inoculated wild-type (WT) and isogenic JAM-A −/− mice perorally with reovirus and found that JAM-A is dispensable for viral replication in the intestine but required for systemic dissemination. Reovirus replication in the brain and tropism for discrete neural regions are equivalent in WT and JAM-A −/− mice following intracranial inoculation, suggesting a function for JAM-A in reovirus spread to extraintestinal sites. JAM-A promotes reovirus infection of endothelial cells, providing a conduit for the virus into the bloodstream. These findings indicate that a broadly expressed IgSF viral receptor specifically mediates hematogenous dissemination in the host.
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structure of reovirus σ1 in complex with its receptor Junctional Adhesion Molecule a
PLOS Pathogens, 2008Co-Authors: Eva Kirchner, Terence S. Dermody, Kristen M Guglielmi, Thilo Stehle, Holger M StraussAbstract:Viral attachment to specific host receptors is the first step in viral infection and serves an essential function in the selection of target cells. Mammalian reoviruses are highly useful experimental models for studies of viral pathogenesis and show promise as vectors for oncolytics and vaccines. Reoviruses engage cells by binding to carbohydrates and the immunoglobulin superfamily member, Junctional Adhesion Molecule-A (JAM-A). JAM-A exists at the cell surface as a homodimer formed by extensive contacts between its N-terminal immunoglobulin-like domains. We report the crystal structure of reovirus attachment protein σ1 in complex with a soluble form of JAM-A. The σ1 protein disrupts the JAM-A dimer, engaging a single JAM-A Molecule via virtually the same interface that is used for JAM-A homodimerization. Thus, reovirus takes advantage of the adhesive nature of an immunoglobulin-superfamily receptor by usurping the ligand-binding site of this Molecule to attach to the cell surface. The dissociation constant (KD) of the interaction between σ1 and JAM-A is 1,000-fold lower than that of the homophilic interaction between JAM-A Molecules, indicating that JAM-A strongly prefers σ1 as a ligand. Analysis of reovirus mutants engineered by plasmid-based reverse genetics revealed residues in σ1 required for binding to JAM-A and infectivity of cultured cells. These studies define biophysical mechanisms of reovirus cell attachment and provide a platform for manipulating reovirus tropism to enhance vector targeting.
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reovirus binding determinants in Junctional Adhesion Molecule a
Journal of Biological Chemistry, 2007Co-Authors: Kristen M Guglielmi, Eva Kirchner, Geoffrey H Holm, Thilo Stehle, Terence S. DermodyAbstract:Junctional Adhesion Molecule-A (JAM-A) serves as a serotype-independent receptor for mammalian orthoreoviruses (reoviruses). The membrane-distal immunoglobulin-like D1 domain of JAM-A is required for homodimerization and binding to reovirus attachment protein σ1. We employed a structure-guided mutational analysis of the JAM-A dimer interface to identify determinants of reovirus binding. We purified mutant JAM-A ectodomains for solution-phase and surface plasmon resonance binding studies and expressed mutant forms of full-length JAM-A in Chinese hamster ovary cells to assess reovirus binding and infectivity. Mutation of residues in the JAM-A dimer interface that participate in salt-bridge or hydrogen-bond interactions with apposing JAM-A monomers abolishes the capacity of JAM-A to form dimers. JAM-A mutants incapable of dimer formation form complexes with the σ1 head that are indistinguishable from wild-type JAM-A-σ1 head complexes, indicating that σ1 binds to JAM-A monomers. Residues Glu61 and Lys63 of β-strand C and Leu72 of β-strand C′ in the dimer interface are required for efficient JAM-A engagement of strain type 3 Dearing σ1. Mutation of neighboring residues alters the kinetics of the σ1-JAM-A binding interaction. Prototype reovirus strains type 1 Lang and type 2 Jones share similar, although not identical, binding requirements with type 3 Dearing. These results indicate that reovirus engages JAM-A monomers via residues found mainly on β-strands C and C′ of the dimer interface and raise the possibility that the distinct disease phenotypes produced in mice following infection with different strains of reovirus are in part attributable to differences in contacts with JAM-A.
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a chimeric adenovirus vector encoding reovirus attachment protein σ1 targets cells expressing Junctional Adhesion Molecule 1
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: George T Mercier, Terence S. Dermody, Jacquelyn A. Campbell, Thilo Stehle, James D Chappell, Michael A BarryAbstract:The utility of adenovirus (Ad) vectors for gene transduction can be limited by receptor specificity. We developed a gene-delivery vehicle in which the potent Ad5 vector was genetically reengineered to display the mucosal-targeting σ1 protein of reovirus type 3 Dearing (T3D). A σ1 construct containing all but a small virion-anchoring domain was fused to the N-terminal 44 aa of Ad5 fiber. This chimeric attachment protein Fibtail-T3Dσ1 forms trimers and assembles onto Ad virions. Fibtail-T3Dσ1 was recombined into the Ad5 genome, replacing sequences encoding wild-type fiber. The resulting vector, Ad5-T3Dσ1, expresses Fibtail-T3Dσ1 and infects Chinese hamster ovary cells transfected with human or mouse homologs of the reovirus receptor, Junctional Adhesion Molecule 1 (JAM1), but not the coxsackievirus and Ad receptor. Treatment of Caco-2 intestinal epithelial cells with either JAM1-specific antibody or neuraminidase reduced transduction by Ad5-T3Dσ1, and their combined effect decreased transduction by 95%. Ad5-T3Dσ1 transduces primary cultures of human dendritic cells substantially more efficiently than does Ad5, and this transduction depends on expression of JAM1. These data provide strong evidence that Ad5-T3Dσ1 can be redirected to cells expressing JAM1 and sialic acid for application as a vaccine vector.
