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

The influence of metronidazole on the level of expression of adhesion molecules ICAM-1, VCAM-1 and E-selectin on the surface of vascular endothelial cells activated with B. fragilis endotoxins and enterotoxin was examined. Three enterotoxigenic (ETBF) strains and one nonenterotoxigenic (NTBF) strain were used for lipopolysaccharide extraction. Enterotoxin was prepared from the culture supernatant of the reference B. fragilis ATCC 43858 strain. Expression of adhesion molecules on vascular endothelial cells (HMEC-1 cell line) was determined after their stimulation with bacterial compounds at the concentration of 10 micrograms/ml in the presence of metronidazole at the concentration of 4 micrograms/ml. Endothelial cells were activated for 4 hours (E-selectin expression) and for 24 hours (ICAM-1 and VCAM-1 expression). Adhesion molecules were detected in immunoenzymatic test (ELISA) with mouse, monoclonal antibodies against human ICAM-1, VCAM-1 and E-selectin. The results of experiments suggest, that metronidazole enhances the expression of examined adhesion molecules on endothelial cells. This antimicrobial agent causes some changes in the expression of endothelial ICAM-1, VCAM-1 and E-selectin stimulated by B. fragilis endotoxins and enterotoxin.
 ...
PMID:[The effect of metronidazole on stimulation of adhesion molecule expression on the surface of vascular endothelial cells by Bacteroides fragilis endotoxins and enterotoxin]. 1175 5

Enoxaparin is a low molecular weight heparin, widely accepted as anticoagulant or antithrombotic drug, and is likely to have a role in acute inflammation. To evaluate the anti-inflammatory potential of enoxaparin, we investigated the direct effect of the drug on the activation of endothelial cells. For this purpose we set up an in vitro system in which cultured valvular endothelial cells (VEC) activated by tumor necrosis factor alpha or lipopolysaccharide were exposed to a monocytic cell line; these conditions induced a significant adhesion of monocytes to VEC. Adhesion assays, ELISA, and flow cytometric analysis revealed that pretreatment with enoxaparin, at a relevant plasma concentration (16 microg/ml), acts upon activation of VEC by inhibition of lipopolysaccharide-induced E-selectin expression and tumor necrosis factor stimulated ICAM-1 expression, thus reducing monocyte adhesion to VEC. These results suggest a novel function of enoxaparin, namely to protect VEC from activation and inhibiting the expression of cell adhesion molecules.
 ...
PMID:A novel attribute of enoxaparin: inhibition of monocyte adhesion to endothelial cells by a mechanism involving cell adhesion molecules. 1190 Dec 99

Evidence shows that leukocyte recruitment into inflamed liver sinusoids does not require selectins, with one notable exception: ischemia-reperfusion (I/R). We used intravital microscopy to directly visualize the liver microcirculation during I/R and localized endotoxemia (liver superfused with lipopolysaccharide). General anti-selectin therapy (fucoidan) or anti-adhesion therapy with an antithrombin inhibitor (hirudin) was also used. Many neutrophils rolled and adhered in postsinusoidal vessels and sequestered in the sinusoids during I/R and local endotoxin superfusion. Although fucoidan blocked rolling in both forms of inflammation, leukocyte recruitment into sinusoids was only blocked in I/R. Adhesion was also inhibited in postischemic sinusoids with a second anti-adhesive agent (hirudin). Because liver I/R inevitably induces ischemia upstream in the intestine, anti-selectin therapy may prevent intestinal injury, which could prevent downstream liver inflammation. To test this hypothesis, we completely removed the intestine and rerouted blood flow from the superior mesenteric artery to the superior mesenteric vein. I/R was induced in the liver microcirculation, and many leukocytes rolled and adhered in postsinusoidal venules and adhered in sinusoids. Although fucoidan significantly reduced the rolling in postsinusoidal vessels, adhesion persisted in the sinusoids. Our data suggest that anti-adhesion therapy is effective in liver I/R in the sinusoids and postsinusoidal venules, perhaps in part due to its beneficial effect on the intestine.
 ...
PMID:Molecular mechanisms of leukocyte recruitment in postischemic liver microcirculation. 1206 1

Endothelial lipase (EL), a new member of the lipoprotein lipase gene family, plays a central role in high density lipoprotein metabolism. Previous studies indicated that EL is expressed in endothelial cells, macrophages, and smooth muscle cells in atherosclerotic lesions in human coronary arteries. However, the functional role of EL in the local vessel wall remains obscure. In this study, we evaluated the ability of EL to modulate monocyte adhesion to the endothelial cell surface. EL mRNA and protein levels were markedly increased in tissues of the mouse model of inflammation induced by lipopolysaccharide injection. Adhesion assays in vitro revealed that overexpression of EL in COS7 or Pro5 cells enhanced monocyte bindings to the EL-expression cells. Heparin or heparinase treatment inhibited EL-mediated increases of monocyte adhesion in a dose-dependent manner. Moreover, ex vivo adhesion assays revealed that the number of adherent monocytes on aortic strips was significantly increased in EL transgenic mice and decreased in EL knock-out mice as compared with wild-type mice. These results suggest that EL on the endothelial cell surface can promote monocyte adhesion to the vascular endothelium through the interaction with heparan sulfate proteoglycans. Thus, the up-regulation of EL by inflammatory stimuli may be involved in the progression of inflammation.
 ...
PMID:Endothelial lipase modulates monocyte adhesion to the vessel wall. A potential role in inflammation. 1548 5

Polymyxin B is a lipopolysaccharide binding antibiotic used to inactivate potential lipopolysaccharide contaminations when evaluating the activity of different agents on innate immune cells. We report that polymyxin B is able to induce directly in monocyte-derived human dendritic cells (DCs) several functional and molecular modifications characteristic of DCs undergoing a maturation process. DCs incubated with polymyxin B up-regulate the expression of HLA class I and II, the co-stimulatory CD86 molecule, and show an increase in the fraction of adherent cells at short time, which persist at 48 h of incubation. Adhesion to the plate was required for the polymyxin B-induced DCs maturation. A transient activation of IkappaB-alpha/NF-kappaB and ERK1/2 pathways at short time and a further ERK1/2 activation at long term were also detected. Neither up-regulation of the maturation marker CD83 nor activation of p38 nor induction of cytokines secretion was observed in DCs treated with polymyxin B. We demonstrated that inhibition of IkappaB-alpha/NF-kappaB pathway abolishes polymyxin B effects. ERK1/2 inhibition instead allowed DCs treated with polymyxin B to progress in their maturation process as revealed by the increased up-regulation of the CD83 co-stimulatory molecules, the activation of p38, and the reduced adhesion to culture plates at 48 h of incubation. Our results indicate that polymyxin B induces a partial maturation of human DCs through increased adhesion to a substrate and activation of the IkappaB-alpha/NF-kappaB pathway. The increased ERK1/2 activation observed, even though correlating with the initial phases of the maturation process, actually inhibits the occurrence of full maturation.
 ...
PMID:Direct effects of polymyxin B on human dendritic cells maturation. The role of IkappaB-alpha/NF-kappaB and ERK1/2 pathways and adhesion. 1567 Oct 28

In the immune system, integrins have essential roles in leukocyte trafficking and function. These include immune cell attachment to endothelial and antigen-presenting cells, cytotoxicity, and extravasation into tissues. The integrin leukocyte function-associated antigen-1 (LFA-1), which is exclusively expressed on hematopoietic cells, has been intensely studied since this receptor is important for many functions of the immune system. LFA-1 is involved in a) the interaction between T-cells and antigen presenting cells, b) the adhesion of cells to post-capillary high endothelial venules or to activated endothelium at sites of inflammation (extravasation), c) the control of cell differentiation and proliferation, and d) the regulation of T-cell effector functions. Therefore, a precise understanding of the spatial and temporal control of LFA-1 interaction with its cellular counter-receptors, the intercellular adhesion molecules (ICAM) -1, -2 and -3, in the various contexts, is of high interest. LFA-1 mediated adhesion is induced by several extracellular stimuli in different cell types. In T-cells, LFA-1 becomes activated upon signaling from the T-cell receptor (TCR), and upon cytokine and chemokine sensing. Adhesion of monocytes to ICAM-1 is induced by lipopolysaccharide (LPS), a component of the bacterial cell wall. To investigate the regulation of LFA-1 adhesiveness, research has focused on the identification of interaction partners of the intracellular portions of the integrin alpha and beta subunits. This review will highlight recent developments on transmembrane and intracellular signaling proteins, which have been implicated in beta-2 integrin activation.
 ...
PMID:Membrane-proximal signaling events in beta-2 integrin activation. 1706 75

Adhesion molecules known to be important for neutrophil recruitment in many other organs are not involved in recruitment of neutrophils into the sinusoids of the liver. The prevailing view is that neutrophils become physically trapped in inflamed liver sinusoids. In this study, we used a biopanning approach to identify hyaluronan (HA) as disproportionately expressed in the liver versus other organs under both basal and inflammatory conditions. Spinning disk intravital microscopy revealed that constitutive HA expression was restricted to liver sinusoids. Blocking CD44-HA interactions reduced neutrophil adhesion in the sinusoids of endotoxemic mice, with no effect on rolling or adhesion in postsinusoidal venules. Neutrophil but not endothelial CD44 was required for adhesion in sinusoids, yet neutrophil CD44 avidity for HA did not increase significantly in endotoxemia. Instead, activation of CD44-HA engagement via qualitative modification of HA was demonstrated by a dramatic induction of serum-derived HA-associated protein in sinusoids in response to lipopolysaccharide (LPS). LPS-induced hepatic injury was significantly reduced by blocking CD44-HA interactions. Administration of anti-CD44 antibody 4 hours after LPS rapidly detached adherent neutrophils in sinusoids and improved sinusoidal perfusion in endotoxemic mice, revealing CD44 as a potential therapeutic target in systemic inflammatory responses involving the liver.
 ...
PMID:Interaction of CD44 and hyaluronan is the dominant mechanism for neutrophil sequestration in inflamed liver sinusoids. 1836 72

Adhesion and degranulation promoting adapter protein (ADAP), a positive regulator of T cell receptor (TCR) signaling, is required for thymocyte development and T cell homeostasis. To investigate the role of ADAP in a T cell-driven autoimmune response, we generated ADAP-deficient, BDC2.5 TCR transgenic, diabetes-prone (C57BL/6) mice (BDC/B6). We observed a striking enhancement of diabetes incidence in ADAP-deficient mice, both in animals homozygous for I-Ag7, and in mice carrying one I-Ab allele (BDC/B6g7/b). Increased disease correlates with significantly reduced numbers of pathological CD4(+) T cells in the mice. Consistent with a state of functional lymphopenia in ADAP-deficient BDC/B6g7/b mice, T cells display increased homeostatic proliferation. Transfer of syngeneic lymphocytes or T cells both blocks ADAP-dependent diabetes and relieves exaggerated homeostatic T cell proliferation observed in ADAP-deficient mice. Marked attenuation in cellularity of the CD4+ single-positive thymocyte compartment in ADAP-deficient BDC/B6g7/b animals suggests a mechanism for induction of the lymphopenia. We conclude that inefficient positive selection in ADAP deficiency results in lymphopenia that leads to enhanced autoimmune diabetes in the BDC/B6g7/b model. Our findings support the notion that ineffective thymic T cell output can be a powerful causative factor in lymphopenia-driven autoimmune diabetes.
 ...
PMID:Defective positive selection results in T cell lymphopenia and increased autoimmune diabetes in ADAP-deficient BDC2.5-C57BL/6 mice. 1838 41

Lipoteichoic acid (LTA) is a major immunostimulatory molecule in the cell wall of Gram-positive bacteria. Adhesion of LTA to a polystyrene surface drastically increased its immunostimulatory potency in human whole blood in comparison to soluble LTA, although only 1% of the LTA had bound, as determined using rhodamine-labelled LTA. The release of the proinflammatory cytokines IL-1beta, TNF and IL-6 and the chemokines IL-8 and G-CSF was increased 2- to 10-fold, but IL-10 release was unaltered. This presentation effect was not shared by lipopolysaccharide (LPS) or other toll-like receptor 2 agonists and was less pronounced in polypropylene vessels. LTA did not induce cytokine release in silicone-coated borosilicate vessels, but covalent coupling of LTA to polystyrene beads restored cytokine induction in these vessels, indicating that presentation of LTA on a surface is in fact essential for its immunostimulatory potency. This novel aspect of presentation as a factor in the recognition of LTA may reflect the physiological situation in the bacterial cell wall, where LTA is anchored in the bacterial membrane and projects through the peptidoglycan. In practical terms, contamination of medical devices with components of Gram-positive bacteria may pose an underestimated inflammatory risk.
 ...
PMID:Presentation of lipoteichoic acid potentiates its inflammatory activity. 1851 54

The extracellular matrix (ECM) of the central nervous system (CNS) is rapidly degraded following acute brain injury, leading to inflammation and neuronal death. Under these conditions, the pro-inflammatory cytokine interleukin-1beta (IL-1beta) is primarily produced by microglial cells and is a key mediator of neuroinflammation, but whether the ECM regulates microglial IL-1 synthesis after CNS injury remains unknown. This study aimed to investigate whether cell attachment to ECM molecules modulated IL-1beta production in activated microglia in vitro. We found adhesion to fibronectin, fibrillin-1 and laminin promoted microglial cell adhesion and spreading, potentiated by bacterial lipopolysaccharide (LPS) treatment. Adhesion to fibronectin (but not fibrillin-1 or laminin) regulated IL-1beta expression via a cell density-dependent mechanism, whereby fibronectin-induced cell proliferation resulted in less IL-1beta being produced. These data suggest an important regulatory mechanism of IL-1 production, associated with microglial migration and proliferation, driven by ECM degradation and/or synthesis in an injured brain.
 ...
PMID:Adhesion to fibronectin regulates interleukin-1 beta expression in microglial cells. 1925 Sep 67


<< Previous 1 2 3 4 5 6 7 8 Next >>