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Increased Adhesion (increased + adhesion)
Selected AbstractsTransfection of the c- erbB2/neu gene upregulates the expression of sialyl Lewis X, ,1,3-fucosyltransferase VII, and metastatic potential in a human hepatocarcinoma cell lineFEBS JOURNAL, Issue 12 2001Fei Liu The pCMV4 plasmid containing the cancer-promoting gene, c- erbB2/neu, was cotransfected into the human hepatocarcinoma cell line 7721 with the pcDNA3 vector, which contains the ,neo' selectable marker. Several clones showing stable expression of c- erbB2/neu were established and characterized by determination of c- erbB2/neu mRNA and its encoded protein p185. Expression of Lewis antigens and ,1,3-fucosyltransferases and the biological behavior of 7721 cells after c- erbB2/neu transfection were studied using mock cells transfected with the vectors pCMV4 and pcDNA3 as controls. SLex expression on the surface of mock cells was high, whereas expression of SDLex, Lex and SLea was absent or negligible. This is compatible with the abundant expression of ,1,3-fucosyltransferase VII, very low expression of ,fucosyltransferase III/VI, and almost absent expression of ,1,3-fucosyltransferase IV in the mock cells. After transfection of c- erbB2/neu, expression of SLex and ,1,3-fucosyltransferase VII were simultaneously elevated, but that of ,fucosyltransferase III/VI was not altered. The expression of both SLex and ,1,3-fucosyltransferase VII correlated positively with the expression of c- erbB2/neu in different clones, being highest in clone 13, medium in clone 6, and lowest in clone 7. In addition, the adhesion of 7721 cells to human umbilical vein endothelial cells (HUVECs) or P-selectin, as well as cell migration and invasion, were increased in c- erbB2/neu -transfected cells. These increases also correlated positively with the expression intensities of c- erbB2/neu, SLex and ,1,3-fucosyltransferase VII in the different clones, whereas cell adhesion to fibronectin correlated negatively with these variables. mAbs to SLex (KM93) and SDLex (FH6) significantly and slightly, respectively, abolished cell adhesion to HUVECs or P-selectin and cell migration and invasion. mAbs to SDLex and SLea did not suppress cell adhesion to HUVECs nor inhibit cell migration and invasion. Transfection of ,1,3-fucosyltransferase VII cDNA into 7721 cells showed similar results to transfection of c- erbB2/neu, and the increased adhesion to HUVECs, cell migration, and invasion were also inhibited significantly by KM93 and slightly by FH6. These results indicate that expression of ,1,3-fucosyltransferase VII and its specific product, SLex, and their capacity for cell adhesion, migration and invasion are closely related. Therefore, the c- erbB2/neu gene is proposed to be a metastasis-promoting gene, and its effects are at least partially mediated by the increased expression of ,1,3-fucosyltransferase VII and SLex. [source] Putative dual role of ephrin-Eph receptor interactions in inflammationIUBMB LIFE, Issue 7 2006Andrei I. Ivanov Abstract Inflammation is associated with a decreased adhesion between endothelial cells in blood vessels and an increased adhesion of circulating leukocytes to vascular endothelium and to epithelia of internal organs. These changes lead to leukocyte extravasation and tissue transmigration. We propose that ephrins and Eph receptors play important, but underappreciated, signaling roles in these processes. At early stages of inflammation, EphA2 receptor and ephrin-B2 are overexpressed in endothelial and epithelial cells, thus leading to those events (expression of adhesion molecules on the cell surface and reorganization of the intracellular cytoskeleton) that cause cell repulsion and disruption of endothelial and epithelial barriers. At later stages of inflammation, expression of EphA1, EphA3, EphB3, and EphB4 on leukocytes and endothelial cells decreases, thus promoting adhesion of leukocytes to endothelial cells. Taking into consideration the abundance of ephrins and Eph receptors in tissues and the robustness of their signaling effects, the proposed involvement is likely to be substantial and may constitute a novel therapeutic target. iubmb Life, 58: 389-394, 2006 [source] Endothelial cell growth on silicon modified hydrogenated amorphous carbon thin filmsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008A. A. Ogwu Abstract The biological response of human microvascular endothelial cells (HMEC-1) seeded on Si-DLC films and on control surfaces was evaluated in terms of initial cell enhancement, growth, and cytotoxicity. The microstructure of the films was characterised by Raman spectroscopy and X-ray photoelectron spectroscopy. The effect of changes in microstructure, surface energy, surface electronic state, and electronic conduction, on the biological response of the films to endothelial cells was investigated. Endothelial cell adhesion and growth was found to be affected by changes in the microstructure of the films induced by silicon doping and thermal annealing. We observed a significant statistical difference in endothelial cell count between the as-deposited DLC and Si-DLC films using the one sample t -test at a p -value of 0.05. We also found a statistically significant difference between the adhesion of HMEC films on DLC and Si-DLC films at various annealing temperatures using the one-way ANOVA F statistic test at p < 0.05 and the post-hoc Tukey test. One sample t -test at p < 0.05 of MTT-assay results showed the endothelial cells to be viable when seeded on DLC/Si-DLC films. We suspect that the increased adhesion of endothelial cells induced by increasing the amount of silicon in the Si-DLC films is associated with the development of a suitable surface energy due to silicon addition, which neither favored cell denaturing nor preferential water spreading before cellular attachment on the film surface. The presence of an external positively charged dipole on the Si-DLC films confirmed by our Kelvin probe measurements is also expected to enhance the adhesion of endothelial cells that are well known to carry a negative charge. The Si-DLC films investigated hold potential promise as coatings for haemocompatible artificial implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Role of p38 mitogen-activated protein kinase in antiphospholipid antibody-mediated thrombosis and endothelial cell activationJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2007M. E. VEGA-OSTERTAG Summary.,Background:,The purpose of this study was to examine whether SB 203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor, is effective in reversing the pathogenic effects of antiphospholipid antibodies. Methods:,The adhesion of THP-1 monocytes to cultured endothelial cells (EC) treated with immunoglobulin G (IgG) from a patient with antiphospholipid syndrome (IgG-APS) or control IgG (IgG-NHS) in the presence and absence of SB 203580 was examined. The size of an induced thrombus in the femoral vein, the adhesion of leukocytes to EC of cremaster muscle, tissue factor (TF) activity in carotid artery and in peritoneal macrophages, the ex vivo expression of vascular cell adhesion molecule-1 (VCAM-1) in aorta preparations and platelet aggregation were studied in mice injected with IgG-APS or control IgG-NHS and with or without SB 203580. Results:,SB 203580 significantly reduced the increased adhesion of THP-1 to EC in vitro, the number of leukocytes adhering to EC, the thrombus size, the TF activity in carotid arteries and in peritoneal mononuclear cells, and the expression of VCAM-1 in aorta of mice, and completely abrogated platelet aggregation induced by IgG-APS. Conclusion:,These data suggest that targeting the p38 MAPK pathway may be valuable in designing new therapy modalities for treating thrombosis in patients with APS. [source] A Val193Met mutation in GPIIIa results in a GPIIb/IIIa receptor with a constitutively high affinity for a small ligandBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2001John Fullard We have identified a patient designated as (GTa) with Glanzmann's Thrombasthenia (GT) diagnosed on the basis of a prolonged bleeding time and failure of the patient's platelets to aggregate. The number of glycoprotein (GP)IIb/IIIa receptors on the platelet surface was 37% of normal and those receptors displayed a defect in soluble fibrinogen binding. Nevertheless, GTa platelets showed increased adhesion to solid-phase fibrinogen and binding affinity for the RGD-mimetic 3H-SC52012, a non-peptide GPIIb/IIIa antagonist. Dithiothreitol (DTT) and ADP enhanced the affinity for [3H]-SC52012 in normal platelets, but had little effect in GTa platelets. These findings suggested that GTa platelets were locked in an altered affinity state. Genetic analysis showed that GTa was a compound heterozygote for the GPIIIa gene. One allele showed a deletion at the 3, end of exon 3 resulting in a premature stop codon. The second GPIIIa allele had a G to A transition at nucleotide 577, resulting in a Val193Met substitution. HEK 293T cells transfected with mutant GPIIb/IIIaV193M bound [3H]-SC52012 with a higher affinity than wild-type GPIIb/IIIa, and this was not increased by DTT. The mutant receptor distinguishes between platelet adhesion and aggregation, and demonstrates the phenotype that may be expected when platelet aggregation alone is inhibited. [source] Adhesion of Epstein,Barr virus-positive natural killer cell lines to cultured endothelial cells stimulated with inflammatory cytokinesCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2008H. Kanno Summary Chronic active Epstein,Barr virus (EBV) infection (CAEBV) is characterized by chronic recurrent infectious mononucleosis-like symptoms. Approximately one-fourth of CAEBV patients develop vascular lesions with infiltration of EBV-positive lymphoid cells. Furthermore, EBV-positive natural killer (NK)/T cell lymphomas often exhibit angiocentric or angiodestructive lesions. These suggest an affinity of EBV-positive NK/T cells to vascular components. In this study, we evaluated the expression of adhesion molecules and cytokines in EBV-positive NK lymphoma cell lines, SNK1 and SNK6, and examined the role of cytokines in the interaction between NK cell lines and endothelial cells. SNKs expressed intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) at much higher levels than those in EBV-negative T cell lines. SNKs produced the larger amount of tumour necrosis factor (TNF)-,, which caused increased expression of ICAM-1 and VCAM-1 in cultured human endothelial cells, than that from EBV-negative T cell lines. Furthermore, SNKs exhibited increased adhesion to cultured endothelial cells stimulated with TNF-, or interleukin (IL)-1,, and the pretreatment of cytokine-stimulated endothelial cells with anti-VCAM-1-antibodies reduced cell adhesion. These indicate that the up-regulated expression of VCAM-1 on cytokine-stimulated endothelial cells would be important for the adhesion of EBV-positive NK cells and might initiate the vascular lesions. [source] | ||||||||||