scholarly journals Occurrence of a novel fucose-containing pentaglycosylceramide with blood-group-B active determinant in Xenopus blastula cells: its possible involvement in cell-cell adhesion

1995 ◽  
Vol 306 (3) ◽  
pp. 821-827 ◽  
Author(s):  
K Nomura ◽  
N Nakajo ◽  
K I P Hidari ◽  
H Nomura ◽  
M Murata ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Adhesion ◽  
Xenopus Laevis ◽  
Blood Group ◽  
Blood Group Antigen ◽  
Gas Chromatography Mass Spectrometry ◽  
Cell Contact ◽  
Chemical Structures ◽  
Group B ◽  
Cell Cell

For understanding of the biological function of glycoconjugates during embryogenesis and morphogenesis, Xenopus laevis is considered a very useful animal model. We have found that blood-group-active molecules characteristically were distributed in the cell-cell contact region of Xenopus blastula cells. The chemical nature of blood-group-active glycoconjugates, including glycosphingolipids, is little known. T.l.c.-immunostaining using anti-blood-group-antigen antibodies showed that many species of blood group-B-active glycosphingolipids existed in the neutral glycosphingolipid fraction extracted from Xenopus laevis eggs. Among the B-active glycosphingolipids detected, two major components with the fastest mobility on a t.l.c. plate, tentatively termed XN-1 and XN-2, were isolated, and their chemical structures were characterized by gas chromatography-mass spectrometry, immunological anlaysis, fast-atom-bombardment mass spectrometry and 1H-n.m.r. spectroscopy. Both XN-1 and XN-2 had an identical pentaoligosaccharide structure, but differed in their ceramide moiety. The chemical structure is: [table: see text]. This is a novel type of pentaglycosylceramide with blood-group B activity, in that it lacks N-acetylhexosamine in its core carbohydrate structure. In this paper, a possible involvement of the blood-group antigen in the cell-adhesion process of Xenopus embryonic cells is discussed.

Involvement of blood-group-B-active trisaccharides in Ca 2+ -dependent cell-cell adhesion in the Xenopus blastula

1998 ◽  
Vol 208 (1) ◽  
pp. 9-18 ◽  
Author(s):  
K. H. Nomura ◽  
Ryuji Kobayashi ◽  
Megumi Fujisue-Sakai ◽  
Souhei Mizuguchi ◽  
Kazuya Nomura ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Blood Group ◽  
Dependent Cell ◽  
Group B ◽  
Cell Cell

scholarly journals Holospiniferoside: A New Antitumor Cerebroside from The Red Sea Cucumber Holothuria spinifera: In Vitro and In Silico Studies

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1555
Author(s):  
Enas E. Eltamany ◽  
Usama Ramadan Abdelmohsen ◽  
Dina M. Hal ◽  
Amany K. Ibrahim ◽  
Hashim A. Hassanean ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Red Sea ◽  
Active Site ◽  
Sea Cucumber ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometric Analysis ◽  
Chemical Structures ◽  
In Silico Studies ◽  
Red Sea Cucumber

Chemical investigation of the methanolic extract of the Red Sea cucumber Holothuria spinifera led to the isolation of a new cerebroside, holospiniferoside (1), together with thymidine (2), methyl-α-d-glucopyranoside (3), a new triacylglycerol (4), and cholesterol (5). Their chemical structures were established by NMR and mass spectrometric analysis, including gas chromatography–mass spectrometry (GC–MS) and high-resolution mass spectrometry (HRMS). All the isolated compounds are reported in this species for the first time. Moreover, compound 1 exhibited promising in vitro antiproliferative effect on the human breast cancer cell line (MCF-7) with IC50 of 20.6 µM compared to the IC50 of 15.3 µM for the drug cisplatin. To predict the possible mechanism underlying the cytotoxicity of compound 1, a docking study was performed to elucidate its binding interactions with the active site of the protein Mdm2–p53. Compound 1 displayed an apoptotic activity via strong interaction with the active site of the target protein. This study highlights the importance of marine natural products in the design of new anticancer agents.

scholarly journals Changes in E-cadherin rigidity sensing regulate cell adhesion

2017 ◽  
Vol 114 (29) ◽  
pp. E5835-E5844 ◽  
Author(s):  
Caitlin Collins ◽  
Aleksandra K. Denisin ◽  
Beth L. Pruitt ◽  
W. James Nelson
Keyword(s):  
Cell Adhesion ◽  
Signaling Molecules ◽  
Membrane Dynamics ◽  
Cell Contact ◽  
Adhesion Assay ◽  
Cell Periphery ◽  
Actin Organization ◽  
Rigidity Sensing ◽  
E Cadherin ◽  
Cell Cell

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin–dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell–cell adhesion assay and live cell imaging of cell–cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell–cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell–cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell–cell adhesion.

Antisense RNA inactivation of gene expression of a cell-cell adhesion protein (gp64) in the cellular slime mold Polysphondylium pallidum

1996 ◽  
Vol 109 (5) ◽  
pp. 1009-1016
Author(s):  
S. Funamoto ◽  
H. Ochiai
Keyword(s):  
Gene Expression ◽  
Cell Adhesion ◽  
Antisense Rna ◽  
Resistant Cell ◽  
Cell Contact ◽  
Cellular Slime Mold ◽  
Adhesion Protein ◽  
Cell Adhesion Protein ◽  
Polysphondylium Pallidum ◽  
Cell Cell

The gp64 protein of Polysphondylium pallidum has been shown to mediate EDTA-stable cell-cell adhesion. To explore the functional role of gp64, we made an antisense RNA expression construct designed to prevent the gene expression of gp64; the construct was introduced into P. pallidum cells and the transformants were characterised. The antisense RNA-expressing clone L3mc2 which had just been harvested at the growth phase tended to re-form in aggregates smaller in size than did the parental cells in either the presence or absence of 10 mM EDTA. In contrast, 6.5-hour starved L3mc2 cells remained considerably dissociated from each other after 5 minutes gyrating, although aggregation gradually increased by 50% during a further 55 minutes gyrating in the presence of 10 mM EDTA. Correspondingly, L3mc2 lacked specifically the cell-cell adhesion protein, gp64. We therefore conclude that the gp64 protein is involved in forming the EDTA-resistant cell-cell contact. In spite of the absence of gp64, L3mc2 exhibited normal developmental processes, a fact which demonstrates that another cell-cell adhesion system exists in the development of Polysphondylium. This is the first report in which an antisense RNA technique was successfully applied to Polysphondylium.

E-cadherin mediated cell adhesion recruits SAP97 into the cortical cytoskeleton

1998 ◽  
Vol 111 (8) ◽  
pp. 1071-1080 ◽  
Author(s):  
S.M. Reuver ◽  
C.C. Garner
Keyword(s):  
Cell Adhesion ◽  
Model Systems ◽  
Molecular Organization ◽  
Cell Contact ◽  
Adhesion Sites ◽  
Associated Proteins ◽  
Adhesion Complex ◽  
Cortical Cytoskeleton ◽  
E Cadherin ◽  
Cell Cell

Members of the SAP family of synapse-associated proteins have recently emerged as central players in the molecular organization of synapses. In this study, we have examined the mechanism that localizes one member, SAP97, to sites of cell-cell contact. Utilizing epithelial CACO-2 cells and fibroblast L-cells as model systems, we demonstrate that SAP97 is associated with the submembranous cortical cytoskeleton at cell-cell adhesion sites. Furthermore, we show that its localization into this structure is triggered by E-cadherin. Although SAP97 can be found in an E-cadherin/catenin adhesion complex, this interaction seems to be mediated by the attachment of SAP97 to the cortical cytoskeleton. Our results are consistent with a model in which SAP97 is recruited to sites of cell-cell contact via an E-cadherin induced assembly of the cortical cytoskeleton.

Analysis of Cell‐Cell Contact Mediated by Ig Superfamily Cell Adhesion Molecules

2001 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter Sonderegger ◽  
Stefan Kunz ◽  
Christoph Rader ◽  
Daniel M. Suter ◽  
Esther T. Stoeckli
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Cell Contact ◽  
Ig Superfamily ◽  
Cell Cell

scholarly journals Thrombospondin-1, a natural inhibitor of angiogenesis, regulates platelet-endothelial cell adhesion molecule-1 expression and endothelial cell morphogenesis.

1997 ◽  
Vol 8 (7) ◽  
pp. 1329-1341 ◽  
Author(s):  
N Sheibani ◽  
P J Newman ◽  
W A Frazier
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Cell Contact ◽  
Platelet Endothelial Cell Adhesion ◽  
Cell Adhesion Molecule 1 ◽  
Endothelial Cell Adhesion ◽  
Cell Cell

Expression of thrombospondin-1 (TS1) in polyoma middle-sized T (tumor)-transformed mouse brain endothelial cells (bEND.3) restores a normal phenotype and suppresses their ability to form hemangiomas in mice. We show that TS1 expression results in complete suppression of platelet-endothelial cell adhesion molecule-1 (PECAM-1) expression and altered cell-cell interactions in bEND.3 cells. To further investigate the role of PECAM-1 in regulation of endothelial cell-cell interactions and morphogenesis, we expressed human (full length) or murine (delta 15) PECAM-1 isoforms in TS1-transfected bEND.3 (bEND/TS) cells. Expression of either human or murine PECAM-1 resulted in an enhanced ability to organize and form networks of cords on Matrigel, an effect that was specifically blocked by antibodies to PECAM-1. Anti-PECAM-1 antibodies also inhibited tube formation in Matrigel by normal human umbilical vein endothelial cells. However, PECAM-1-transfected bEND/TS cells did not regain the ability to form hemangiomas in mice and the expressed PECAM-1, unlike the endogenous PECAM-1 expressed in bEND.3 cells, failed to localize to sites of cell-cell contact. This may be, in part, attributed to the different isoforms of PECAM-1 expressed in bEND.3 cells. Using reverse transcription-polymerase chain reaction, we determined that bEND.3 cells express mRNA encoding six different PECAM-1 isoforms, the isoform lacking both exons 14 and 15 (delta 14&15) being most abundant. Expression of the murine delta 14&15 PECAM-1 isoform in bEND/TS cells resulted in a similar phenotype to that described for the full-length human or murine delta 15 PECAM-1 isoform. The delta 14&15 isoform, despite the lack of exon 14, failed to localize to sites of cell-cell contact even in clones that expressed it at very high levels. Thus, contrary to recent reports, lack of exon 14 is not sufficient to result in junctional localization of PECAM-1 isoforms in bEND/TS cells.

scholarly journals N-Cadherin Association with Lipid Rafts Regulates Its Dynamic Assembly at Cell-Cell Junctions in C2C12 Myoblasts

2005 ◽  
Vol 16 (5) ◽  
pp. 2168-2180 ◽  
Author(s):  
Marie Causeret ◽  
Nicolas Taulet ◽  
Franck Comunale ◽  
Cyril Favard ◽  
Cécile Gauthier-Rouvière
Keyword(s):  
Plasma Membrane ◽  
Cell Adhesion ◽  
Lipid Rafts ◽  
Membrane Lipid ◽  
Cell Junctions ◽  
Cell Contact ◽  
C2c12 Myoblasts ◽  
Cell Contacts ◽  
Dynamic Assembly ◽  
Cell Cell

Cadherins are homophilic cell-cell adhesion molecules implicated in cell growth, differentiation, and organization into tissues during embryonic development. They accumulate at cell-cell contact sites and act as adhesion-activated signaling receptors. Here, we show that the dynamic assembly of N-cadherin at cell-cell contacts involves lipid rafts. In C2C12 myoblasts, immunofluorescence and biochemical experiments demonstrate that N-cadherin present at cell-cell contacts is colocalized with lipid rafts. Disruption of lipid rafts leads to the inhibition of cell-cell adhesion and disorganization of N-cadherin–dependent cell-cell contacts without modifying the association of N-cadherin with catenins and its availability at the plasma membrane. Fluorescent recovery after photobleaching experiments demonstrate that at the dorsal plasma membrane, lipid rafts are not directly involved in the diffusional mobility of N-cadherin. In contrast, at cell-cell junctions N-cadherin association with lipid rafts allows its stabilization enabling the formation of a functional adhesive complex. We show that lipid rafts, as homophilic interaction and F-actin association, stabilize cadherin-dependent adhesive complexes. Homophilic interactions and F-actin association of N-cadherin are both required for its association to lipid rafts. We thus identify lipid rafts as new regulators of cadherin-mediated cell adhesion.

scholarly journals Photocatalytic Degradation of Trifluralin, Clodinafop-Propargyl, and 1,2-Dichloro-4-Nitrobenzene As Determined by Gas Chromatography Coupled with Mass Spectrometry

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Niyaz A. Mir ◽  
A. Khan ◽  
M. Muneer ◽  
S. Vijayalakhsmi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Photocatalytic Degradation ◽  
Degradation Mechanism ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionization Mass ◽  
Water Medium ◽  
Fragmentation Pattern ◽  
Chemical Structures ◽  
Clodinafop Propargyl

Phototransformation is considered one of the most key factors affecting the fate of pesticides. Therefore, our study focused on photocatalytic degradation of three selected pesticide derivatives: trifluralin (1), clodinafop-propargyl (2), and 1,2-dichloro-4-nitrobenzene (3). The degradation was carried out in acetonitrile/water medium in the presence of titanium dioxide (TiO2) under continuous purging of atmospheric air. The course of degradation was followed by thin-layer chromatography and gas chromatography-mass spectrometry techniques. Electron ionization mass spectrometry was used to identify the degradation species. GC-MS analysis indicates the formation of several intermediate products which have been characterized on the basis of molecular ion, mass fragmentation pattern, and comparison with NIST library. The photocatalytic degradation of pesticides of different chemical structures manifested distinctly different degradation mechanism. The major routes for the degradation of pesticides were found to be (a) dealkylation, dehalogenation, and decarboxylation, (b) hydroxylation, (c) oxidation of side chain, if present, (d) isomerization and cyclization, (e) cleavage of alkoxy bond, and (f) reduction of triple bond to double bond and nitro group to amino.

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