Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To test the hypothesis that nitric oxide (NO) limits endothelial activation, we treated cytokine-stimulated human saphenous vein endothelial cells with several NO donors and assessed their effects on the inducible expression of vascular cell adhesion molecule-1 (VCAM-1). In a concentration-dependent manner, NO inhibited interleukin (IL)-1 alpha-stimulated VCAM-1 expression by 35-55% as determined by cell surface enzyme immunoassays and flow cytometry. This inhibition was paralleled by reduced monocyte adhesion to endothelial monolayers in nonstatic assays, was unaffected by cGMP analogues, and was quantitatively similar after stimulation by either IL-1 alpha, IL-1 beta, IL-4, tumor necrosis factor (TNF alpha), or bacterial lipopolysaccharide. NO also decreased the endothelial expression of other leukocyte adhesion molecules (E-selectin and to a lesser extent, intercellular adhesion molecule-1) and secretable cytokines (IL-6 and IL-8). Inhibition of endogenous NO production by L-N-monomethyl-arginine also induced the expression of VCAM-1, but did not augment cytokine-induced VCAM-1 expression. Nuclear run-on assays, transfection studies using various VCAM-1 promoter reporter gene constructs, and electrophoretic mobility shift assays indicated that NO represses VCAM-1 gene transcription, in part, by inhibiting NF-kappa B. We propose that NO's ability to limit endothelial activation and inhibit monocyte adhesion may contribute to some of its antiatherogenic and antiinflammatory properties within the vessel wall.
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PMID:Nitric oxide decreases cytokine-induced endothelial activation. Nitric oxide selectively reduces endothelial expression of adhesion molecules and proinflammatory cytokines. 754 86

We investigated the effect of interleukin-1 (IL-1) activation of human umbilical vein endothelium (HUVE) on human monocyte transendothelial migration induced by chemotactic factors. Monocyte migration across unactivated endothelium in response to macrophage inflammatory protein-1 alpha (MIP-1 alpha), RANTES, platelet-activating factor (PAF), or monocyte chemoattractant protein-1 (MCP-1) was completely inhibited (90%) by monoclonal antibodies (mAbs; 60.3) to CD18 of the CD11/CD18 complex on the monocyte and partially inhibited (by 75%) in response to C5a. When the HUVE was stimulated with IL-1 alpha (5 h, 0.1 ng/ml), monocyte migration in response to C5a, MIP-1 alpha, RANTES, or PAF was no longer inhibited by mAb to CD18. However, migration was blocked by the combination of mAb to the alpha 4-integrin (CD49d) chain of very late antigen-4 (CD49d/CD29) with the mAb to CD18. In contrast to the above stimuli, activation of the HUVE with IL-1 alpha inhibited the transendothelial migration of monocytes in response to MCP-1. mAbs to the adhesion molecules up-regulated on HUVE by IL-1, i.e., E-selectin (CD62E), intercellular adhesion molecule-1 (CD54) or vascular cell adhesion molecule-1 (CD106), did not reverse the inhibitory effect. Transendothelial migration in response to MCP-1 but not to C5a was inhibited by the treatment of monocytes with culture supernatant from IL-1 alpha-stimulated (but not from unstimulated) HUVE. Such supernatant contained chemotactic activity for monocytes, and a mAb to MCP-1 blocked the migration inhibitory effect of IL-1 activation of the HUVE monolayer, as well as the chemotactic activity in the supernatant from IL-1-stimulated HUVE. The inhibitory effect on migration of IL-1-stimulated HUVE was specific for monocytes because polymorphonuclear leukocyte transendothelial migration in response to IL-8 (a related chemokine) was not inhibited by IL-1 activation of HUVE.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:IL-1 activation of endothelium supports VLA-4 (CD49d/CD29)-mediated monocyte transendothelial migration to C5a, MIP-1 alpha, RANTES, and PAF but inhibits migration to MCP-1: a regulatory role for endothelium-derived MCP-1. 754 7

Treatment of human endothelial cells with cytokines such as interleukin-1, tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma induces the expression of specific leukocyte adhesion molecules on the endothelial cell surface. Interfering with either leukocyte adhesion or adhesion protein upregulation is an important therapeutic target as evidenced by the potent anti-inflammatory actions of neutralizing antibodies to these ligands in various animal models and in patients. In the present study we report that cotreatment of human endothelial cells with certain hydroxyflavones and flavanols blocks cytokine-induced ICAM-1, VCAM-1, and E-selectin expression on human endothelial cells. One of the most potent flavones, apigenin, exhibited a dose- and time-dependent, reversible effect on adhesion protein expression as well as inhibiting adhesion protein upregulation at the transcriptional level. Apigenin also inhibited IL-1 alpha-induced prostaglandin synthesis and TNF-alpha-induced IL-6 and IL-8 production, suggesting that the hydroxyflavones may act as general inhibitors of cytokine-induced gene expression. Although apigenin did not inhibit TNF-alpha-induced nuclear translocation of NF-kappa B(p50(NFKB1)/p65(RelA)) we found this flavonoid did inhibit TNF-alpha induced beta-galactosidase activity in SW480 cells stably transfected with a beta-galactosidase reporter construct driven by four NF-kappa B elements, suggesting an action on NF-kappa B transcriptional activation. Adhesion of leukocytes to cytokine-treated endothelial cells was blocked in endothelial cells cotreated with apigenin. Finally, apigenin demonstrated potent anti-inflammatory activity in carrageenan induced rat paw edema and delayed type hypersensitivity in the mouse. We conclude that flavonoids offer important therapeutic potential for the treatment of a variety of inflammatory diseases involving an increase in leukocyte adhesion and trafficking.
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PMID:Flavonoids inhibit cytokine-induced endothelial cell adhesion protein gene expression. 763 22

Endothelial cell activation is achieved by the rapid, protein synthesis-independent induction of a characteristic set of genes. Because of the abundance of binding sites for the transcription factor NF-kappa B in the regulatory region of the aforementioned genes, we hypothesized that this factor might play a key role. Reactive oxygen intermediates act as second messengers in the activation of NF-kappa B. We have used the antioxidant pyrrolidine dithiocarbamate to analyze the effect of NF-kappa B inhibition on TNF alpha-induced EC activation in vitro. We show that pyrrolidine dithiocarbamate strongly reduces the TNF alpha-mediated induction of E-selectin, VCAM-1, ICAM-1, PAI-1, tissue factor, IL-8 and I kappa B-alpha. We present evidence identifying NF-kappa B as a central of EC activation. Therefore, this factor may represent a prime target for therapeutic intervention in pathologic conditions associated with EC activation such as allo- and xenograft rejection, atherosclerosis, ischemic reperfusion injury and vasculitis.
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PMID:Inhibition of NF-kappa B by pyrrolidine dithiocarbamate blocks endothelial cell activation. 754 93

During bacterial infections at mucosal sites, neutrophils migrate to the mucosa and cross the epithelial barrier. We have examined neutrophil migration across Escherichia coli-stimulated uroepithelial cell layers in an attempt to more fully understand this process. Stimulation of uroepithelial cells with E. coli or interleukin-1 alpha (IL-1 alpha) induced transepithelial neutrophil migration in a time- and stimulant dose-dependent manner. Uroepithelial cell lines and nontransformed uroepithelial cells expressed intercellular adhesion molecule-1 (ICAM-1) but not ICAM-2, E-selectin, or P-selectin. Epithelial ICAM-1 expression was enhanced after stimulation with E. coli or IL-1 alpha. Anti-ICAM-1 antibody reduced transepithelial neutrophil migration by 61 to 85%, indicating that neutrophils bound ICAM-1 on the epithelial surface. Antibodies to CD18 and CD11b reduced migration by 70 to 79%, suggesting that CD11b/CD18 (Mac-1) was acting as the neutrophil receptor for ICAM-1 in this process. Anti-CD11a antibodies had no effect on neutrophil migration. In conclusion, E. coli induced ICAM-1- and Mac-1-dependent transepithelial neutrophil migration. Previous studies have shown that urinary tract epithelial cells secrete IL-8 when exposed to E. coli or IL-1 alpha. These observations suggest that epithelial cells play an active role in neutrophil migration during urinary tract infections.
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PMID:Escherichia coli induces transuroepithelial neutrophil migration by an intercellular adhesion molecule-1-dependent mechanism. 755 19

Monocytes and polymorphonuclear leukocytes (PMNLs) migrate across cytokine (interleukin-1, tumor necrosis factor) activated endothelium or unstimulated endothelium in response to chemotactic factors in vitro and in vivo utilizing the CD11/CD18 (i.e., beta 2 integrin) adhesion molecule complex. However, in vivo studies have suggested that under some conditions and/or in certain tissues, leukocyte migration can also proceed via CD11/CD18-independent mechanisms. Here we compared adhesion mechanisms involved in the migration of 51Cr-labeled blood monocytes and PMNLs across human umbilical vein endothelium (HUVE) monolayers. We observed that monocyte transendothelial migration was not inhibited by monoclonal antibody (mAb) to CD18, when the HUVE was activated with IL-1 and the chemotactic factor C5a induced the migration. This CD18-independent monocyte migration was blocked by treatment of the monocyte with mAb to beta 1 or alpha 4 integrin, suggesting that very late activation antigen 4 (VLA-4) on the monocyte served as the alternative migration mechanism. In contrast to monocytes, mAb to CD18 inhibited PMNL migration to C5a across IL-1-activated HUVE, but only by 66%, significantly less than with C5a alone (84%) or IL-1-activated HUVE alone (95%). The migration of anti-CD18 mAb-treated PMNLs was not inhibited by function-blocking mAbs to sialyl Lewisx, L-selectin, beta 1 or alpha 4 integrin, the beta 3-related leukocyte response integrin, IL-8, or platelet-activating factor (PAF) antagonists, alone or in combination. Antibody-blocking studies of the ligands on HUVE indicated that E-selectin may be partially involved in this CD18-independent PMNL migration but that ICAM-1, VCAM-1, PECAM-1, and P-selectin are not involved. Of several chemotactic factors tested, C5a and C5adesArg in activated plasma were the most active in inducing CD18-independent migration of PMNLs across IL-1-activated HUVE. These results demonstrate that (1) monocytes can utilize VLA-4 for optimal transendothelial migration and (2) PMNLs may have a novel CD18-independent migration mechanism that is activated by C5a in conjunction with one or more ligands on cytokine-activated endothelium. This may involve, in part, E-selectin interacting with a yet to be identified counterreceptor on PMNLs.
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PMID:CD11/CD18-independent transendothelial migration of human polymorphonuclear leukocytes and monocytes: involvement of distinct and unique mechanisms. 772 14

The present study was designed to investigate whether cells cultured from Kaposi's sarcoma (KS), a vascular tumor with a prominent leukocyte infiltration, express molecules important for the recruitment and activation of leukocytes. KS cells expressed intercellular adhesion molecule-1, which was augmented by exposure to IL-1 beta or TNF-alpha. Unlike endothelial cells, resting or cytokine-activated KS cells did not express appreciable levels of intercellular adhesion molecule-2, vascular cell adhesion molecule-1, and E-selectin on their surface. Weak expression of vascular cell adhesion molecule-1 mRNA was detectable by Northern blot analysis and, most clearly, by PCR analysis. Upon exposure to inflammatory cytokines, KS cells produced the attractant/activating lipid platelet-activating factor. KS cells expressed appreciable levels of the chemotactic cytokines, monocyte chemotactic protein-1 (MCP-1) and IL-8, as determined by Northern blot analysis, immunoassay, or bioassay. Chemokine production was augmented by IL-1 beta or TNF-alpha. MCP-1 expression was also detected in KS lesions by in situ hybridization. The set of molecules identified in the present study is probably important in determining the prominent leukocyte infiltration observed in KS. Tumor-associated leukocytes may amplify autocrine/paracrine circuits that sustain KS proliferation and contribute to recruitment of host vascular cells.
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PMID:Expression of adhesion molecules, platelet-activating factor, and chemokines by Kaposi's sarcoma cells. 796 47

Endotoxin [lipopolysaccharide (LPS)] is a potent inflammatory stimulus and can activate human umbilical vein endothelium (HUVE) for leucocyte adhesiveness and transendothelial migration. Here we investigated the role of HUVE-secreted cytokines in this process. When HUVE monolayers were grown on filters and preincubated for 3 hr with LPS, 51Cr-labelled polymorphonuclear leucocytes (PMNL) migrated across the HUVE in a dose- and time-dependent manner. Maximal PMNL transmigration with LPS (1 ng/ml) was 26 +/- 3% of added PMNL in 75 min. Neutralizing antibodies to interleukin-1 alpha (IL-1 alpha) and IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-8 or recombinant IL-1 receptor antagonist had no effect on the activation by LPS of the HUVE for supporting migration of PMNL. The HUVE 'activated state' declined with prolonged (22 hr) exposure to LPS, as reflected by a decrease in PMNL transendothelial migration to 5.5 +/- 1% and in the expression of the endothelial cell adhesion molecule, E-selectin, as compared to stimulation with LPS for 3 hr. However, simultaneous exposure to interferon-gamma (IFN-gamma) (200 IU/ml) and LPS maintained maximal PMNL transendothelial migration (28 +/- 4%) for at least 24 hr, prolonged E-selectin expression by HUVE and superinduced intracellular adhesion molecule-1 (ICAM-1) expression. The PMNL transendothelial migration was blocked by > 90% by monoclonal antibody (mAb) to CD18 with either 3 hr of LPS or 22 hr LPS + IFN-gamma stimulation. Migration was partially inhibited by mAb to E-selectin (30-40%) or to ICAM-1 (35-45%) and by a combination of both reagents (50-60%) under both stimulation conditions. Thus, LPS activation of HUVE for PMNL transendothelial migration: (a) does not require secretion of IL-1, TNF-alpha or IL-8 by the endothelium, (b) IFN-gamma enhances and prolongs endothelial activation by LPS and may increase leucocyte infiltration in LPS or bacterial inflammatory reactions, and (c) CD18-dependent mechanisms are equally important for PMNL transendothelial migration under both acute (3 hr) and prolonged (22 hr LPS + IFN-gamma) activation of endothelium.
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PMID:Endotoxin activation of endothelium for polymorphonuclear leucocyte transendothelial migration and modulation by interferon-gamma. 810 89

IL-8 belongs to the family of chemotactic cytokines and may play an important role in the inflammatory response. In the current studies, a murine mAb (DM/C7) to human rIL-8 was found to have protective effects in inflammatory lung injury in rats. DM/C7 was nonreactive with the rat cytokine-induced neutrophil chemoattractant peptide. In vivo, DM/C7 blocked the glycogen-induced accumulation of neutrophils in rats and was highly protective against lung and dermal vascular injury after deposition of IgG immune complexes. The latter model of injury has recently been shown to be E-selectin dependent. The protective effects of DM/C7 correlated with reduced tissue accumulation of neutrophils, as measured by myeloperoxidase content. DM/C7 reacted with an epitope expressed by TNF-alpha-stimulated rat pulmonary artery endothelial cells and with the pulmonary vascular endothelium after intrapulmonary deposition of IgG immune complexes. In the model of IgG immune complex-induced lung injury, the protective effects of DM/C7 were abolished by prior absorption of the antibody with human rIL-8. Polyclonal antibody to cytokine-induced neutrophil chemoattractant peptide failed to protect against IgG immune complex-induced vascular injury even though this antibody blocked the in vitro chemotactic activity of cytokine-induced neutrophil chemoattractant. In the model of rapidly developing lung injury due to systemic activation of C after infusion of cobra venom factor, DM/C7 was not protective. As well, in the neutrophil-independent model of IgA immune complex-induced lung injury, treatment with DM/C7 was not protective. These data indicate that in inflammatory lung injury that is linked to E-selectin-dependent recruitment of neutrophils in rats, antibody to human IL-8 also blocks recruitment of neutrophils and thereby affords protection against lung injury. The data suggest the presence of an IL-8-like product in this model of lung injury.
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PMID:Inhibition of lung inflammatory reactions in rats by an anti-human IL-8 antibody. 839 May 38

Endothelial cell (EC) activation is a consistent feature of discordant xenograft rejection. Treatment of xenograft recipients with complement inhibitors and xenoreactive natural antibody depletion leads to delayed xenograft rejection associated with a cellular infiltrate comprising up to 20% natural killer (NK) cells. To determine the importance of NK cells in xenograft rejection, we studied EC activation and cytotoxicity in co-cultures containing human NK cells and porcine EC. The addition of freshly isolated NK cells to porcine EC resulted in EC cell activation, characterized by the induction of mRNA and protein for the adhesion molecule E-selectin and the chemotactic cytokine interleukin (IL)-8. The induction of E-selectin and IL-8 occurred with three separate sources of NK cells: purified CD56+ve cells, the NK cell clone B22, and the Fc receptor-deficient NK cell line NK92. Transwell cultures demonstrated that direct NK-EC contact was required for the EC induction of E-selectin and IL-8. These effects could not be inhibited with human recombinant tumor necrosis factor-alpha receptor, and the transfer of supernatants or cell lysates from activated EC to secondary cultures did not result in EC activation. The addition of human IgG enhanced the level of E-selectin expression and cellular cytotoxicity, and resulted in tumor necrosis factor-alpha and interferon-gamma secretion. Thus, human NK cells can lyse or activate EC by direct cell contact and the addition of IgG enhances EC activation and NK cell cytokine secretion. These findings implicate NK cells in EC activation and cell-mediated xenograft rejection.
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PMID:Direct activation of porcine endothelial cells by human natural killer cells. 860 81


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