Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regulation by dexamethasone of intercellular adhesion molecule-1 (ICAM-1) in cultured monolayers of the human umbilical vein endothelial cell line EAhy926 was investigated. Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in combination or lipopolysaccharide (LPS) alone gave time- and dose-dependent increases in ICAM-1. Sustained expression of ICAM-1 was observed after short exposure (30 min) to TNF-alpha + IFN-gamma, but not to LPS. LPS-induced ICAM-1 expression was not inhibited by interleukin-1 (IL-1) receptor antagonist (0.01-100 micrograms/ml). Dexamethasone (1,000 nM) did not inhibit TNF-alpha + IFN-gamma-induced ICAM-1 expression or mRNA induction. In contrast, dexamethasone dose dependently (0.1-1,000 nM) inhibited LPS-induced ICAM-1 expression; however, its effect on mRNA was not established, because ICAM-1 mRNA induced by LPS was not detected at the time points investigated in this study (3 and 20 h). Adhesion of unstimulated human neutrophils to EAhy926 monolayers activated with TNF-alpha + IFN-gamma or LPS was increased in the presence of dexamethasone at low doses, whereas neutrophil adhesion to LPS- but not cytokine-stimulated endothelial cells was significantly reduced (P < 0.05) in the presence of a high dose of dexamethasone (1,000 nM). In conclusion, dexamethasone was demonstrated to regulate the expression and function of ICAM-1 in a stimulus-dependent manner.
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PMID:Regulation of ICAM-1 by dexamethasone in a human vascular endothelial cell line EAhy926. 877 19

Previous work from our group has contributed to demonstrate the role of conditioning related release of proinflammatory cytokines in induction of acute graft-versus-host disease (GVHD) following allogeneic bone marrow transplantation (BMT). In the present report we show that ionizing radiation (IR) in a clinical relevant dose upregulates intercellular adhesion molecule 1 (ICAM-1) on cultured human microvascular endothelial cells (HMEC). Bacterial endotoxin (lipopolysaccharide, LPS) in a concentration corresponding to serum levels seen during clinical endotoxemia, is capable of further enhancing ICAM-1 expression on irradiated cells. Adhesion assays with freshly isolated peripheral blood mononuclear cells (PBMC) revealed that increased ICAM-1 on IR-treated endothelial cells led to an increased adhesion of PBMC. Again, this effect could be superinduced by LPS. Recombinant human interleukin 10 (IL-10), an antagonistic cytokine known to function as an LPS antagonist, was able to counteract the LPS-mediated enhancement of IR-triggered ICAM-1 induction and PBMC adhesion. In contrast, IL-10 could not inhibit irradiation caused effects. IL-10 seemed to interfere with the translocation of preformed intracellular ICAM-1 to the cell membrane. To investigate whether this superinductive function of IR and LPS on endothelial cells is of clinical relevance, mice were treated with total body irradiation (TBI) and inoculated with a single dose of LPS. Immunohistochemical analyses of murine tissues demonstrated that LPS superinduces IR-triggered ICAM-1 also in vivo. These findings may be of clinical importance as they suggest that the endothelium is activated after radiotherapy or TBI used for conditioning in bone marrow transplantation. The activated endothelium in turn may facilitate the accumulation of effector cells at sites of inflammation.
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PMID:Influence of bacterial endotoxin on radiation-induced activation of human endothelial cells in vitro and in vivo: protective role of IL-10. 882 83

Adhesion of macrophages is a crucial event that determines the number and function of macrophages at inflammatory sites. The aim of this study was to elucidate the role of mesangial cells in the regulation of macrophage adhesiveness. J774.2 macrophages were suspended in serial dilutions of mesangial cell conditioned medium (MC medium) and seeded on plastic tissue culture plates. MC medium did not affect the initial adhesion of macrophages but induced subsequent detachment in a concentration-dependent manner. A similar effect was observed when macrophages were plated on plastic coated with laminin, collagen type IV or Matrigel. The reduced adhesiveness was reversible, and cell viability was unaffected by MC medium, indicating that the effect is not due to cytotoxicity. Conditioned media from fibroblastic, epithelial and endothelial cell lines did not induce macrophage detachment. To identify the active component in MC medium, we examined the involvement of transforming growth factor-beta 1 (TGF-beta 1) in the process. Mesangial cells constitutively expressed TGF-beta 1 mRNA, and MC medium contained the active form of TGF-beta 1. Exogenously added TGF-beta 1 induced macrophage detachment in a dose-dependent manner, and an anti-TGF-beta 1 neutralizing antibody partially abolished the activity of MC medium, indicating the involvement of TGF-beta 1 as an active component. Compared to adherent cells, detached macrophages showed reduced mitogenic activity and blunted induction of IL-1 beta and IL-6 in response to lipopolysaccharide. These data demonstrate that TGF-beta 1 is a mesangial cell-derived factor that impairs adhesiveness of macrophages and confers blunted responses to a specific stimulus. These findings suggest one potential mechanism for macrophage clearance from inflamed glomeruli.
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PMID:Mesangial cell-derived transforming growth factor-beta 1 reduces macrophage adhesiveness with consequent deactivation. 884 Feb 72

Adhesion of circulating tumor cells to microvascular endothelium plays an important role in tumor metastasis to distant organs. The purpose of this study was to determine whether nitric oxide (NO) would attenuate tumor cell adhesion (TCA) to naive or lipopolysaccharide (LPS)-treated postcapillary venules. A melanoma cell line, RPMI 1846, was shown to be much more adhesive to postcapillary venules isolated from rat mesentery than to corresponding precapillary arterioles. Although venules exposed to LPS for 4 h demonstrated an increased adhesivity for the melanoma cells, TCA to LPS-treated arterioles was not altered. Isolated venules exposed to DETA/NO (1 mM), an NO donor, for 30 min prior to tumor cell perfusion prevented the increment in adhesion induced by LPS and attenuated TCA to naive postcapillary venules. While L-arginine (100 microM), an NO precursor, failed to decrease TCA to naive postcapillary venules, this treatment abolished LPS-stimulated TCA to postcapillary venules. The effect of L-arginine was reversed by administration of N(omega)-nitro-L-arginine methyl ester (L-NAME, 100 microM), an NO synthase (NOS) inhibitor. These observations indicate that both exogenous and endogenous NO modulate TCA to postcapillary venules. To assess the role of NO-induced activation of cGMP in the reduction in TCA produced by DETA/NO, two additional series of experiments were conducted. In the first series, LY-83583 (10 microM), a guanylyl cyclase inhibitor, was shown to completely reverse the effect of DETA/NO on TCA to both naive and LPS-activated postcapillary venules. On the other hand, administration of 8-bromoguanosine 3',5'-cyclic monophosphate (8-B-cGMP) (1 mM), a cell permeant cGMP analog, mimicked the effect of DETA/NO and reduced TCA to LPS-stimulated postcapillary venules. These data suggest that (a) tumor cells are more likely to adhere to postcapillary venules than to corresponding precapillary arterioles, (b) LPS enhances TCA to postcapillary venules, (c) both exogenously applied (DETA/NO) and endogenously generated (L-arginine) NO attenuate the enhanced adhesion induced by LPS, but only DETA/NO reduced TCA to naive postcapillary venules, and (d) the NO-induced reduction in TCA to LPS-activated postcapillary venules occurs by a cGMP-dependent mechanism.
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PMID:Nitric oxide reduces tumor cell adhesion to isolated rat postcapillary venules. 887 7

1. An antisense approach to block nitric oxide (NO) synthesis was developed, complementing the widely used chemical inhibitors and overcoming problems associated with their use in studying the roles of NO. 2. Murine macrophage cell lines (J774.2) were generated expressing a 500 bp sequence from inducible NO synthase (iNOS) in either the antisense or sense orientation, driven by the SV40 promoter/enhancer region. 3. Messenger RNA derived from the transfected sequences was detected by a specific cDNA probe. Cells expressing sense and antisense iNOS RNA were characterized further. 4. The antisense lines produced 22-97% less NO than the sense lines on stimulation with lipopolysaccharide (LPS) in the range 1 ng ml-1 - 10 micrograms ml-1, as determined by nitrite production. One antisense line in particular, A10, expressed substantially less iNOS protein on LPS stimulation as determined by western blot analysis. 5. Adhesion of the antisense line, A10, to cytokine-stimulated murine endothelial cells (sEnd.1 line) was significantly higher than adhesion of the sense lines. There was a negative correlation between the amount of NO produced, as determined by nitrite accumulation, and the level of adhesion of the transfected lines. This indicates and anti-adhesive role of NO, produced by macrophages during the 15 min of the assay, in adhesion to endothelial cells. 6. This novel approach allowed the roles of NO in adhesion to be investigated with the substantial advantage that the contribution of NO produced rapidly by activated macrophages could be studied separately from that produced in a continuous manner by endothelial cells. 7. These lines, and the extension of this approach, will be of great use in dissecting the contributions of NO produced by different cell types to its many potential functions.
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PMID:Inhibition of nitric oxide synthase by antisense techniques: investigations of the roles of NO produced by murine macrophages. 911 90

It is well known that adherence of monocytes (MO) to extracellular matrix substrates or tissue culture plastic activates these cells and induces the expression of a multitude of genes. Especially, it was described, that MO are primed by cell adhesion to produce higher amounts of some cytokines, e.g. interleukin (IL)-8 and tumor necrosis factor alpha (TNF-alpha). In order to investigate adherence-induced effects upon cytokine production, we seeded MO into tissue cultures and stimulated cells by lipopolysaccharide (LPS) simultaneously or at later time points. An increasing time-lag between cell adhesion and LPS-stimulation led to differential effects upon cytokine production: whereas TNF was upregulated (in accordance with reports by others), granulocyte colony-stimulating factor (G-CSF) was considerably down-regulated. In contrast, G-CSF production did not change, when cells were kept under non-adherent conditions in whole blood. In adherent cultures down-regulation of G-CSF could already be observed after two hours with a maximum after 24 h and was paralleled by a much lower abundance of G-CSF mRNA. Adhesion induced a significant suppression of G-CSF comparable to MO, if mature macrophages derived from MO in vitro were examined. Furthermore, two other cytokines, granulocyte-macrophage (GM)-CSF and IL-6, were also down-regulated following adhesion. In conclusion, activation of mononuclear phagocytes by adhesion can lead to "priming" for the production of some cytokines and at the same time to "silencing" for the production of others.
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PMID:Differential effects of cell adherence on LPS-stimulated cytokine production by human monocytes and macrophages. 914 30

Agonist signals delivered through cell surface Fas induce apoptosis. However, the apoptotic program can be modulated by signals from the environment, and in particular, by signals delivered through adhesion molecules. Because neutrophil functional activity in inflammation is contingent on cell survival, and because circulating neutrophils normally die rapidly through a constitutively expressed apoptotic program, we evaluated Fas-mediated apoptosis in resting and inflammatory human neutrophils. We show that normal neutrophils respond to Fas engagement with accelerated rates of apoptosis, but cross-linking of beta2 integrins or priming with bacterial lipopolysaccharide (LPS) prevents this increase. Adhesion molecule cross-linking results in increased intracellular glutathione (GSH). Augmentation of intracellular GSH with exogenous GSH or N-acetylcysteine is sufficient to reduce the Fas-triggered increase in apoptotic rates. Prevention of the activation induced GSH increase by buthionine sulfoximine, a cell permeable inhibitor of GSH biosynthesis, restored Fas responsiveness in activated neutrophils, an effect that could be blocked with exogenous GSH. Taken together, these data show that Fas-induced signaling for neutrophil apoptosis is blocked in a redox sensitive manner by costimulatory signals delivered through beta2 integrins or activation by LPS, and provide a biologic explanation for sustained neutrophil survival in the inflammatory environment.
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PMID:Augmented intracellular glutathione inhibits Fas-triggered apoptosis of activated human neutrophils. 916 61

We analyzed the influence of heavy-metal ions on human umbilical vein endothelial cells (HUVEC) in comparison to proinflammatory cytokines (TNF-alpha, IL-1beta) and lipopolysaccharide (LPS). Adhesion molecule and cytokine expressions are upregulated by heavy-metal exposure. Expression of E-selectin on the cell surface was strongly induced by 1-mM concentrations of NiCl2 and CoCl2, whereas ZnCl2 and CrCl3 had no influence. Furthermore, it is shown that NiCl2 induces mRNA expression of E-selectin, intercellular adhesion molecule-1, IL-6 and IL-8 in a 1-mM concentration. The transcription factor NF-kappaB is known to be involved in the regulation of adhesion molecule expression in endothelial cells after activation by proinflammatory cytokines. We demonstrated that treatment of HUVEC with Ni2+ and Co2+ ions induces the translocation of NF-kappaB p65 and also p50 into the nucleus. NF-kappaB binding activity is enhanced under the influence of heavy metals as determined by mobility shift analysis. P65 and p50 are components of the NF-kappaB complexes as confirmed by supershift analysis. We could show that activation at the protein level is accompanied by induction of NF-kappaB p65 mRNA expression. HUVEC also express the NF-kappaB inhibitor I kappaB-alpha (MAD-3). In the early phase of activation by Ni2+ and Co2+ ions, disappearance of I kappaB-alpha in the cytoplasm accompanied p65 translocation, followed by its gradual reappearence. Because I kappaB mRNA could be upregulated by NiCl2 as well as by a mixture of cytokines, we suggest that the replenishment of the inhibitor in the cytoplasm is caused by de novo I kappaB gene expression. In addition to the enhanced DNA-binding activity of NF-kappaB, another transcription factor, AP-1, was also augmented in HUVEC stimulated by NiCl2, CoCl2 or by proinflammatory mediators and the phorbol ester PMA. Fos protein is shown to be a component of the activated AP-1 complex, as determined by supershift analysis, suggesting that it consists of Jun/Fos heterodimers.
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PMID:Heavy metal ion induction of adhesion molecules and cytokines in human endothelial cells: the role of NF-kappaB, I kappaB-alpha and AP-1. 945 94

Ligation of integrins to an extracellular matrix activates signal transduction systems which produce multiple responses in different cell types. Adhesion often provides a survival signal to cells; disruption of adhesion frequently results in apoptosis. Our laboratory has utilized apoptosis-sensitive and -resistant cell lines to investigate the role of integrin expression and function in regulation of apoptosis in macrophages. Chronic exposure of murine macrophage-like RAW264.7 cells to apoptosis-inducing agents (bacterial lipopolysaccharide and interferon-gamma) resulted in the generation of a derivative cell line (RES) resistant to apoptosis. Observation of RAW and RES cultures indicated a difference in adhesion between the two cell types. The two cell lines also exhibit significant differences in expression of integrins previously characterized to be important in apoptosis.
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PMID:Propensity for macrophage apoptosis is related to the pattern of expression and function of integrin extracellular matrix receptors. 961 Mar 92

Because oleic acid is implicated in the antiatherogenic effects attributed to the Mediterranean diet, we investigated whether this fatty acid can modulate endothelial activation, ie, the concerted expression of gene products involved in leukocyte recruitment and early atherogenesis. We incubated sodium oleate with human umbilical vein endothelial cells for 0 to 72 hours, followed by coincubation of oleate with human recombinant tumor necrosis factor, interleukin (IL)-1alpha, IL-1beta, IL-4, Escherichia coli lipopolysaccharide (LPS), or phorbol 12-myristate 13-acetate for a further 6 to 24 hours. The endothelial expression of vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and intercellular adhesion molecule-1 was monitored by cell surface enzyme immunoassays or flow cytometry, and steady-state levels of VCAM-1 mRNA were assessed by Northern blot analysis. At 10 to 100 micromol/L for >24 hours, oleate inhibited the expression of all adhesion molecules tested. After a 72-hour incubation with oleate and a further 16-hour incubation with oleate plus 1 microg/mL LPS, VCAM-1 expression was reduced by >40% compared with control. Adhesion of monocytoid U937 cells to LPS-treated endothelial cells was reduced concomitantly. Oleate also produced a quantitatively similar reduction of VCAM-1 mRNA levels on Northern blot analysis and inhibited nuclear factor-kappaB activation on electrophoretic mobility shift assays. Incubation of endothelial cells with oleate for 72 hours decreased the relative proportions of saturated (palmitic and stearic) acids in total cell lipids and increased the proportions of oleate in total cell lipids without significantly changing the relative proportions of polyunsaturated fatty acids. Although less potent than polyunsaturated fatty acids in inhibiting endothelial activation, oleic acid may contribute to the prevention of atherogenesis through selective displacement of saturated fatty acids in cell membrane phospholipids and a consequent modulation of gene expression for molecules involved in monocyte recruitment.
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PMID:Oleic acid inhibits endothelial activation : A direct vascular antiatherogenic mechanism of a nutritional component in the mediterranean diet. 997 1


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