Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extensive monocyte recruitment is an early phenomenon associated with the development of atherosclerotic lesions, suggesting an active role for the involvement of adhesion receptors expressed by endothelial cells. In this study we describe the contribution of hemodynamic shear forces in regulating the expression of a few of the monocyte adhesion receptors, including intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), and E-selectin on endothelial cells. A parallel plate flow chamber and recirculating flow loop device was used to expose human umbilical vein endothelial cells (HUVECs) to different levels of shear (2-25 dyn/cm2). Subsequently the cells were analyzed either for shear induced changes in the mRNA levels of adhesion receptors by Northern blot analyses or for changes in the surface expression of ICAM-1 using flow cytometry. Results from the fluorescence analysis showed a transient increase in the surface expression of ICAM-1, 12 hr after exposure to 25 dyn/cm2 shear, returning to basal levels within 24 hr. This was quite different from the time dependent response of ICAM-1 to lipopolysaccharide (LPS), where ICAM-1 expression was maximally induced 18-24 hr post-stimulus. ICAM-1 mRNA level appeared slightly elevated after exposure to shear for 1 hr, compared to basal values, but dropped below basal levels within 6 hr. This biphasic response was seen irrespective of the magnitude of applied shear stress. VCAM-1 mRNA expression, in contrast, decreased below the baseline expression within an hour after onset of flow, and appeared to be considerably down-regulated within 6 hr. After exposure to shear for 24 hr, no increase in mRNA levels could be detected for either molecule, at any shear magnitude. E-selectin mRNA was less responsive to shear stress, especially at the lower magnitudes of shear. After an hour of exposure to flow E-selectin mRNA level appeared slightly reduced compared with control levels, but it remained at this level even after 6 hr of flow. These results indicate that the expression of adhesion receptors is sensitive to local shear stresses in a manner that is molecule specific in the short term even though prolonged exposure to flow results in similar down-regulation for both ICAM-1 and VCAM-1.
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PMID:Shear stress-mediated changes in the expression of leukocyte adhesion receptors on human umbilical vein endothelial cells in vitro. 754 62

Antisense gene suppression has been carried out for human ICAM-1, ELAM-1, and VCAM-1 in cultured human umbilical vein endothelial cells (HUVEC) stimulated by lipopolysaccharide, tumor necrosis factor alpha, or interleukin-1 beta. A panel of antisense phosphorothioate oligodeoxyribonucleotides (PS-ODN), complementary to mRNA or pre-mRNA of these molecules, were tested for their gene suppression activity monitored by radioimmunoassay of the respective cell surface adhesion molecules. Sequences targeted by effective antisense PS-ODNs were located throughout the mRNA and pre-mRNA. "Hot spots" of gene suppression sites for each region were observed. Shift of the PS-ODN hybridizing site upstream or downstream by a few bases resulted in drastic change of gene suppression efficiency. In addition to translation arrest and RNase H activity, a third mechanism was proposed for antisense gene suppression, involving multiple binding sites for PS-ODN and the activities of RNase H and RNases other than RNase H. Suppression of ICAM-1, ELAM-1, or VCAM-1 in HUVEC by their antisense PS-ODNs resulted in the reduction of adhesion of monocytes and U937 to HUVEC. This may suggest cooperativity among the adhesion molecule pairs in endothelial-leukocyte adhesion, since decrease of a single adhesion molecule on EC surface significantly reduced cell-cell adherence.
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PMID:Antisense gene suppression against human ICAM-1, ELAM-1, and VCAM-1 in cultured human umbilical vein endothelial cells. 755 71

Optimal activation of T cells often requires signals delivered by the ligation of T cell receptor (TcR) and those resulting from costimulatory interaction between certain T cell surface accessory molecules and their respective counter receptors on antigen presenting cells. The molecular events underlying the co-stimulatory activity are still not understood fully. Here we describe a 38-42-kDa (B3) protein, present on the surface of lipopolysaccharide-activated B cells, which can provide co-stimulation to resting T cells leading to a predominant release of interleukin (IL)-4 and IL-5 and negligible amounts of IL-2 and interferon-gamma. Binding assay and electron microscopic autoradiography data suggest that this molecule binds T cells, and the same can be competed by unlabeled B3. Characterization experiments point out that B3 shows up as a single prominent peak on reverse phase-high performance liquid chromatography, runs as a single spot in reducing two-dimensional gel electrophoresis, and is a phosphoglycoprotein. The Western analysis indicate that it does not cross-react with antibodies directed against murine ICAM-1, LFA-1 alpha, VCAM-1, HSA, and B7 suggesting the novelty of the protein. The internal amino acid sequence of this molecule suggests that it does not belong to a known category of murine B cell surface molecules.
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PMID:Characterization of novel costimulatory molecules. A protein of 38-42 kDa from B cell surface is concerned with T cell activation and differentiation. 755 3

The role of protein kinase C (PKC) in interleukin-1 beta- (II-1 beta)-, tumor necrosis factor-alpha- (TNF-alpha)-, and lipopolysaccharide- (LPS)-induced vascular cell adhesion molecule-1 (VCAM-1) expression on human umbilical vein endothelial cells (HUVEC) was studied. PKC inhibition or downregulation diminished VCAM-1 mRNA accumulation and protein expression. Interleukin-1 beta, TNF-alpha, and LPS induce nuclear factor (NF)-kappa B-like binding activity, which precedes VCAM-1 transcription. PKC inhibition did not prevent NF-kappa B-like binding activity, indicating that this is PKC-independent, and NF-kappa B-like binding activity is insufficient for transcription of VCAM-1.
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PMID:The role of protein kinase C in the induction of VCAM-1 expression on human umbilical vein endothelial cells. 769 Jul 17

Oxidative stress and expression of the vascular cell adhesion molecule-1 (VCAM-1) on vascular endothelial cells are early features in the pathogenesis of atherosclerosis and other inflammatory diseases. Regulation of VCAM-1 gene expression may be coupled to oxidative stress through specific reduction-oxidation (redox) sensitive transcriptional or posttranscriptional regulatory factors. In cultured human umbilical vein endothelial (HUVE) cells, the cytokine interleukin 1 beta (IL-1 beta) activated VCAM-1 gene expression through a mechanism that was repressed approximately 90% by the antioxidants pyrrolidine dithiocarbamate (PDTC) and N-acetylcysteine (NAC). Furthermore, PDTC selectively inhibited the induction of VCAM-1, but not intercellular adhesion molecule-1 (ICAM-1), mRNA and protein accumulation by the cytokine tumor necrosis factor-alpha (TNF alpha) as well as the noncytokines bacterial endotoxin lipopolysaccharide (LPS) and double-stranded RNA, poly(I:C) (PIC). PDTC also markedly attenuated TNF alpha induction of VCAM-1-mediated cellular adhesion. In a distinct pattern, PDTC partially inhibited E-selectin gene expression in response to TNF alpha but not to LPS, IL-1 beta, or PIC. TNF alpha and LPS-mediated transcriptional activation of the human VCAM-1 promoter through NF-kappa B-like DNA enhancer elements and associated NF-kappa B-like DNA binding proteins was inhibited by PDTC. These studies suggest a molecular linkage between an antioxidant sensitive transcriptional regulatory mechanism and VCAM-1 gene expression that expands on the notion of oxidative stress as an important regulatory signal in the pathogenesis of atherosclerosis.
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PMID:Vascular cell adhesion molecule-1 (VCAM-1) gene transcription and expression are regulated through an antioxidant-sensitive mechanism in human vascular endothelial cells. 769 89

The role of mucosal fibroblasts in intestinal inflammatory reactions is not known. In this study, we demonstrate that fibroblasts grown from histologically normal human duodenal biopsy tissues expressed mRNA genes for granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) when stimulated with lipopolysaccharide (LPS) or IL-1 alpha. The increased mRNA expression of GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and IL-8 in response to IL-1 alpha and LPS stimulation was time- and dose-dependent. In contrast, IL-10 was weakly expressed when fibroblasts were stimulated with LPS, IL-1 alpha or tumour necrosis factor-alpha (TNF-alpha), but the expression was enhanced in the presence of cycloheximide combined with optimal concentrations of LPS, IL-1 alpha or TNF-alpha, IL-1 alpha was a more potent stimulator than LPS for GM-CSF, IL-6, IL-8 and IL-10 expression, but not for IL-1 alpha and IL-1 beta. Increased GM-CSF, IL-6 and IL-8 gene expression was associated with the production of cytokine proteins in culture supernatant, but IL-1 alpha and IL-1 beta remained undetectable. Dexamethasone suppressed both gene expression and protein production of GM-CSF, IL-6 and IL-8 when fibroblasts were exposed to IL-1 alpha. TNF-alpha stimulated the release of GM-CSF, IL-6 and IL-8 and, combined with IL-1 alpha, cytokine production was enhanced synergistically. Finally, both LPS and IL-1 alpha up-regulated ICAM-1 and VCAM-1 gene expression. These findings implicate duodenal fibroblasts in the initiation and/or regulation of intestinal inflammation.
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PMID:GM-CSF, IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, ICAM-1 and VCAM-1 gene expression and cytokine production in human duodenal fibroblasts stimulated with lipopolysaccharide, IL-1 alpha and TNF-alpha. 800 13

Sialic acids decorating blood and cell surface proteins can play important roles in various biological processes. The inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1, as well as bacterial lipopolysaccharide, can activate vascular endothelium, increasing expression of several surface glycoproteins. Here we show that treatment of cultured human endothelial cells (HEC) with TNF-alpha, interleukin-1, or lipopolysaccharide causes increased expression of the enzyme beta-galactoside alpha-2,6-sialytransferase (alpha 2-6STN). TNF-alpha was most effective, inducing a 3.5-fold enhancement of cell-associated sialytransferase activity by 72 h. In addition, activated HEC secreted a large portion of the induced sialyltransferase activity into the medium. Analysis of labeled HEC showed both a relative and an absolute increase of alpha 2,6-linked sialic acid on N-linked oligosaccharides after TNF-alpha stimulation. This coincided with increased expression of endothelial glycoproteins bearing N-linked glycans with alpha 2,6-linked sialic acid detected by the lectin Sambucus nigra agglutinin. The cytokine-inducible endothelial cell adhesion molecules E-selectin, ICAM-1, and VCAM-1 are among these glycoprotein substrates for alpha 2-6STN. These changes also correlated with a substantial increase in binding sites for CD22 beta, a mammalian lectin known to recognize oligosaccharides carrying multiple copies of alpha 2,6-linked sialic acid. Northern analysis revealed increased levels of mRNA encoding alpha 2-6STN. Thus, activation of endothelial cells during inflammatory and immunological processes may induce alpha 2-6STN, which can participate in sialylation of other activation-dependent molecules.
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PMID:Cytokine-induced beta-galactoside alpha-2,6-sialyltransferase in human endothelial cells mediates alpha 2,6-sialylation of adhesion molecules and CD22 ligands. 814 53

We describe the production and characterization of a novel monoclonal antibody (MAb) that recognizes a human endothelial cell antigen expressed mainly in inflamed and malignant disease states. We have used immunohistochemistry to determine the spectrum of reactivity of this MAb compared with that of a MAb to factor VIII-related antigen (MAb FVIII). MAb 4A11 does not react with several myeloid or lymphoid cell lines or with peripheral blood cells. Unlike MAb FVIII, MAb 4A11 does not react with platelets. MAb 4A11 reacts with most vascular endothelial cells in lymphoid tissue but with few (< 10%) endothelial cells in thymus, spleen, liver, lung, adrenal gland, placenta, testes, and skin. MAb 4A11 detects endothelial cells in diseased tissues such as rheumatoid and osteoarthritic synovium and psoriatic skin. Vascular endothelial cells in both adrenal tumors and cutaneous Kaposi's sarcomas lesions are MAb 4A11 reactive. In vitro the 4A11 antigen is not detectable on cultured human umbilical vein endothelial cells and its expression is not induced on these cells by treatment with lipopolysaccharide, interferon-gamma, interleukin-1 and -6, or tumor necrosis factor-alpha. However, in an in vivo model of allergic contact dermatitis the 4A11 antigen is upregulated differentially from other endothelial markers such as E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In this dermal model of inflammation, poison ivy extract is applied to the skin and biopsies taken at 0, 6, and 24 hours. In addition to focal keratinocyte expression, 4A11 antigen is found on 11% of dermal endothelial cells at time 0 and antigen expression increases with time until 24 hours, when 4A11 antigen is present on 63% of the endothelial cells. Using thin layer chromatography, MAb 4A11 reacts with the H-5-2 [Fuc alpha 2Gal beta 4GlcNAc beta 3Gal beta 4Glc beta 1Cer] and Lewis(y)-6 [Fuc alpha 2Gal beta 4(Fuc alpha 3)GlcNAc beta 3Gal beta 4-Glc beta 1Cer] blood group glycolipids. The presence of the novel 4A11 antigen in inflamed and malignant tissues containing many blood vessels and its differential upregulation in allergic contact dermatitis may signify an important function for this antigen in the inflammatory process.
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PMID:4A11, a monoclonal antibody recognizing a novel antigen expressed on aberrant vascular endothelium. Upregulation in an in vivo model of contact dermatitis. 831 Nov 12

We examined the effect of agents which augment intracellular levels of cyclic adenosine monophosphate on the expression of adhesion molecules on human umbilical vein endothelial cells. Surface protein expression of vascular cell adhesion molecule-1, endothelial leukocyte adhesion molecule-1, or intercellular adhesion molecule-1, which is induced by tumor necrosis factor, interleukin-1, and lipopolysaccharide, was not induced by pentoxyfilline, a phosphodiesterase inhibitor, nor by dibutyryl cyclic adenosine monophosphate. Furthermore, neither of these two cyclic adenosine monophosphate elevating agents nor HA 1004, an inhibitor of the cyclic adenosine monophosphate-dependent protein kinase, had any effect on tumor necrosis factor-alpha-induced surface expression of these adhesion molecules. Likewise, cyclic adenosine monophosphate elevating agents were without effect on leukocyte adherence to endothelium stimulated either with these agents alone or in combination with tumor necrosis factor-alpha. Additionally, activators of the stimulatory or inhibitory guanine nucleotide-dependent binding proteins did not affect TNF-alpha-induced surface expression of endothelial leukocyte adhesion molecule-1 or vascular cell adhesion molecule-1.
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PMID:Cytokine-induced adhesion molecule expression on human umbilical vein endothelial cells is not regulated by cyclic adenosine monophosphate accumulation. 839 31

Endothelial cells (EC) are very responsive to proinflammatory cytokines, e.g. interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha), as well as to bacterial lipopolysaccharide. EC are stimulated by these substances to secrete chemotactic factors and to increase expression of cell adhesion molecules (CAM), leading to dramatically altered interactions with leukocytes, e.g. granulocytes and monocytes. In these interactions E-selectin, ICAM-1 and VCAM-1 are known to play an important role, as they are presented by the EC and interact with corresponding ligands on the white blood cell membranes. These adhesion molecules have been studied worldwide in a variety of in vitro experiments using cultured EC. Different passages and mixtures of passages have been used in these experiments, often without any regard to the comparability of the results. In this study the expression of E-selectin, ICAM-1 and VCAM-1 on cultured human umbilical vein EC (HUVEC) obtained from different passages (passages 1-6) was studied after 4, 8 and 24 h of exposure to IL-1 beta and TNF alpha. In previous studies, we have shown that IL-1 beta and TNF alpha increase the expression of E-selectin and ICAM-1 on the cytoplasmatic membranes of HUVEC and human adult EC from the saphenous vein and femoral artery in a similar fashion. Using a comparative quantitative cell enzyme immunoassay, we found that the expression of the adhesion molecules was significantly reduced with increasing passages. There was also a decreased persistence of CAM comparing different periods of stimulation between 6 and 24 h in the different passages. These data indicate that the number of passages plays an important role in the expression of adhesion molecules on EC. The results are relevant for the meaningful planning of comparative in vitro studies on EC presentation of CAM.
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PMID:Comparative studies on vascular endothelium in vitro. 3. Effects of cytokines on the expression of E-selectin, ICAM-1 and VCAM-1 by cultured human endothelial cells obtained from different passages. 855 4


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