Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have shown previously that treatment of human aortic endothelial cells (HAECs) with minimally modified low-density lipoprotein (MM-LDL) induces monocyte but not neutrophil binding. This monocyte binding was not mediated by endothelial E-selectin, P-selectin, vascular cell adhesion molecule-I, or intercellular adhesion molecule-I, suggesting an alternative monocyte-specific adhesion molecule. We now show that moncytic alpha4beta1 integrins mediate binding to MM-LDL-treated endothelial cells. We present data suggesting that the expression of the connecting segment-1 (CS-1) domain of fibronectin (FN) is induced on the apical surface of HAEC by MM-LDL and is the endothelial alpha4beta1 ligand in MM-LDL-treated cells. Although the levels of CS-1 mRNA and protein were not increased, we show that MM-LDL treatment causes deposition of FN on the apical surface by activation of beta1integrins, particularly those associated with alpha5 integrins. Activation of beta1 by antibody 8A2 also induced CS-1-mediated monocyte binding. Confocal microscopy demonstrated the activated beta1 and CS-1colocalize in concentrated filamentous patches on the apical surface of HAEC. Both anti-CS-1 and an antibody to activated beta1 showed increased staining on the luminal endothelium of human coronary lesions with active monocyte entry. These results suggest the importance of these integrin ligand interactions in human atherosclerosis.
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PMID:Minimally modified low-density lipoprotein induces monocyte adhesion to endothelial connecting segment-1 by activating beta1 integrin. 1007 78

Atherogenesis is a multifactorial chronic inflammatory disease in which low plasma levels of HDLs are a strong predictor of the condition. Although the mechanism of protection by HDLs is not precisely known, HDLs have been shown to influence many of the events involved in the development of atherosclerosis. Previously we have shown that HDLs inhibited the cytokine-induced expression of adhesion molecules (E-selectin, VCAM-1, and ICAM-1) by endothelial cells (ECs). As the complete transcriptional regulation of all 3 genes requires the NF-kappaB family of transcription factors, we examined the effect of HDLs on activation of NF-kappaB. We also investigated the effect of HDLs on 2 other cytokine-induced genes, granulocyte-macrophage colony-stimulating factor (GM-CSF) and cyclooxygenase (Cox-2; prostaglandin H2 synthase, EC 0.1.14.99.1). E-selectin expression in response to tumor necrosis factor-alpha (TNFalpha) was, as expected, inhibited in ECs that had been preincubated with HDLs. However, the level of secretion of GM-CSF in the same cultures was no different from control. In a similar manner, although HDLs had no effect on steady-state mRNA levels of GM-CSF, the levels of E-selectin were significantly inhibited by HDLs. In transient cotransfection experiments we found that HDLs inhibited the cytokine-induced expression of a reporter gene driven by the E-selectin proximal promoter (-383 to 80) but had no effect on the expression of a reporter gene driven under the control of the proximal promoter of GM-CSF (-627 to 28). As would be predicted from this differential response, HDLs did not influence the nuclear translocation or DNA binding of NF-kappaB, or alter the kinetics of degradation and resynthesis of the inhibitory protein IkappaBalpha. We found that HDLs synergized with cytokine to enhance the expression of Cox-2 and induce the synthesis of its main EC product, prostacyclin (PGI2), a potent inhibitor of platelet and leukocyte functions. In conclusion, HDL induces an antiinflammatory phenotype in cytokine-induced ECs, synergizing with cytokine to induce elevation of Cox-2 in addition to inhibiting adhesion molecule expression. Our studies show that these differential effects are mediated in a manner that is likely to be independent of NF-kappaB per se.
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PMID:High-density lipoproteins differentially modulate cytokine-induced expression of E-selectin and cyclooxygenase-2. 1019 17

Vascular cell adhesion molecule-1 (VCAM-1) is a mononuclear leukocyte-selective adhesion molecule that is expressed in human vascular endothelial cells at sites of local inflammation. It participates in local endothelial-monocyte interactions during the initiation of atherosclerosis. In the present study, endothelin alone did not induce the surface expression and mRNA accumulation of VCAM-1 in human vascular endothelial cells, but inhibition of endogenous nitric oxide (NO) by N(G)-monomethyl-L-arginine enhanced the surface expression and mRNA accumulation of VCAM-1 stimulated by endothelin-1. It is conceivable that in human vascular endothelial cells, stimulation of an endothelin receptor results in the production of nitric oxide (NO), suppressing the expression of VCAM-1. Endothelin-1 enhanced the surface expression and mRNA accumulation of VCAM-1 in cells treated with tumor necrosis factor alpha (TNF-alpha). The enhancement by endothelin-1 may be explained by the inhibitory effect of TNF-alpha on endothelin-induced NO production. Pretreatment with BQ788 (an endothelin ET(B) receptor antagonist) or inhibitors of nuclear factor kappa B (NF-kappaB) activation completely diminished the synergistic enhancement of VCAM-1 expression by endothelin-1 in TNF-alpha-stimulated vascular endothelial cells, both at the protein and mRNA levels. These findings suggest that the synergistic enhancement of VCAM-1 expression by TNF-alpha and endothelin ET(B) receptor stimulation may be augmented by the induction of NF-kappaB binding activity in human vascular endothelial cells.
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PMID:Endothelin-1 enhances vascular cell adhesion molecule-1 expression in tumor necrosis factor alpha-stimulated vascular endothelial cells. 1020 85

The integrin heterodimer CDllb/CD18 (alphaMbeta2, Mac-1, CR3) expressed on monocytes or polymorphonuclear leukocytes (PMN) is a receptor for iC3b, fibrinogen, heparin, and for intercellular adhesion molecule (ICAM)-1 on endothelium, crucially contributing to vascular cell interactions in inflammation and atherosclerosis. In this report, we summarize our findings on the effects of lipid mediators and lipid-lowering drugs. Exposure of endothelial cells to oxidized low density lipoprotein (oxLDL) induces upregulation of ICAM-1 and increases adhesion of monocytic cells expressing Mac-1. Inhibition experiments show that monocytes use distinct ligands, i.e. ICAM-1 and heparan sulfate proteoglycans for adhesion to oxLDL-treated endothelium. An albumin-transferable oxLDL activity is inhibited by the antioxidant pyrrolidine dithiocarbamate (PDTC), while 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) or lysophosphatidylcholine had no effect, implicating yet unidentified radicals. Sequential adhesive and signaling events lead to the firm adhesion of rolling PMN on activated and adherent platelets, which may occupy areas of endothelial denudation. Shear-resistant arrest of PMN on thrombin-stimulated platelets in flow conditions requires distinct regions of Mac-1, involving its interactions with fibrinogen bound to platelet alphallbbeta3, and with other platelet ligands. Both arrest and adhesion strengthening under flow are stimulated by platelet-activating factor and leukotriene B4, but not by the chemokine receptor CXCR2. We tested whether Mac-1-dependent monocyte adhesiveness is affected by inhibitors of hydroxy-methylglutaryl-Coenzyme A reductase (statins) which improve morbidity and survival of patients with coronary heart disease. As compared to controls, adhesion of isolated monocytes to endothelium ex vivo was increased in patients with hypercholesterolemia. Treatment with statins decreased total and low density lipoprotein (LDL) cholesterol plasma levels, surface expression of Mac-1, and resulted in a dramatic reduction of Mac-1-mediated monocyte adhesion to endothelium. The inhibition of monocyte adhesion was reversed by mevalonate but not LDL in vitro, indicating that isoprenoid precursors are crucial for adhesiveness of Mac-1. Such effects may crucially contribute to the clinical benefit of statins, independent of cholesterol-lowering, and may represent a paradigm for novel, anti-inflammatory mechanisms of action by this class of drugs.
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PMID:Effects of oxidized low density lipoprotein, lipid mediators and statins on vascular cell interactions. 1035 67

Angiogenesis is the development of new blood vessels from the existing vascular bed. In normal conditions this tightly regulated process occurs only during embryonic development, the female reproductive cycle and wound repair. In contrast, in pathological conditions such as malignant growth, atherosclerosis and diabetic retinopathy, angiogenesis becomes persistent due to an imbalance in the interplay between the positive and negative regulatory signals controlling the process. Thus, the control of tumor neovascularization may lead to new therapeutic approaches. Indeed, several anti-angiogenic drugs are currently undergoing preclinical characterization and/or clinical investigation. Recent achievement has clarified the mechanisms of action leading to pathological angiogenesis and has highlighted the role of hypoxia, growth factors, growth factor-receptors, enzymes and cell adhesion molecules involved in the process. This knowledge has permitted the design of receptor antagonists, adhesion molecule blockers and new targeted vascular approaches including gene therapy.
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PMID:Mechanisms of tumor angiogenesis and therapeutic implications: angiogenesis inhibitors. 1039 Jan 41

The cellular adhesion molecule E-selectin is expressed on activated endothelial cells, and is involved in the process of adherence of blood cells to vessel endothelium in inflammatory events such as atherosclerosis. In a recent study we found a Ser128Arg mutation in the EGF domain as well as a Leu554Phe mutation in the membrane domain of E-selectin. We also established increased frequencies of both mutations among young patients with severe coronary atherosclerosis. In the present study we investigated the influence of these mutations on cell adhesion and on the release of soluble E-selectin. Mutants were created by site-directed mutagenesis and COS cells were transfected with E-selectin, either wild-type or mutant. Antibody-binding studies and cell-adhesion assays were performed on transfected COS cells and on interleukin-1 beta-stimulated HUVECs. Soluble E-selectin in supernatants of wild type and Leu554Phe mutant-transfected COS cells was measured by ELISA. We discovered significant differences in the strength of HL-60 cell adhesion for the Ser128Arg mutant: in comparison with the wild type, the strength of adhesion to the mutant was reduced on transfected COS cells (P < 0.01) as well as on stimulated HUVECs (P < 0.01). Significantly diminished release of soluble E-selectin was detected for the Leu554Phe membrane domain mutant, in comparison with the wild type. In summary, the mutations studied here influence the E-selectin function in vitro and may be considered as one of the risk factors involved in the complex pathogenesis of atherosclerosis.
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PMID:Functional characterization of atherosclerosis-associated Ser128Arg and Leu554Phe E-selectin mutations. 1043 30

We investigated the role of endothelial cell and leukocyte adhesion in the pathophysiology of acute stroke. The immunocytochemical expression of adhesion molecules in brain tissue from six patients who died following acute ischaemic stroke showed weak endothelial expression of intercellular adhesion molecule-1 (ICAM-1), but intense expression of vascular cell adhesion molecule-1 (VCAM-1) by astrocytes and endothelial cells from the infarcted, but not the non-infarcted areas. We also measured soluble adhesion molecules E-selectin, ICAM-1, VCAM-1 and von Willebrand factor (all by enzyme-linked immunosorbent assay) in 21 patients after an acute ischaemic stroke (ictus < 12 h), and again 3 months later. Blood levels in the stroke patients were compared with 82 healthy controls and 22 subjects with carotid atherosclerosis. Compared with healthy controls, both patient groups had raised levels of von Willebrand factor (P < 0.02) but the level of soluble VCAM-1 was raised only in patients with acute stroke (P < 0.02). Levels of von Willebrand factor and soluble VCAM-1 in the stroke patients were still high at 3 months follow-up. We suggest that there might be changes in adhesion molecule expression and release in the acute and chronic stages of ischaemic stroke, where blood levels are related to immunocytochemical findings on infarcted brain. These changes may perhaps be part of the complex pathophysiological responses to infarction and repair of brain tissue following stroke.
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PMID:Soluble intercelluar adhesion molecule-1, E-selectin, vascular cell adhesion molecule-1 and von Willebrand factor in stroke. 1045 19

An early event in acute and chronic inflammation and associated diseases such as atherosclerosis and rheumatoid arthritis is the induced expression of specific adhesion molecules on the surface of endothelial cells (ECs), which subsequently bind leukocytes. Peroxisome proliferator-activated receptors (PPARs), members of the nuclear receptor superfamily of transcription factors, are activated by fatty acid metabolites, peroxisome proliferators, and thiazolidinediones and are now recognized as important mediators in the inflammatory response. Whether PPAR activators influence the inflammatory responses of ECs is unknown. We show that the PPAR activators 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), Wyeth 14643, ciglitazone, and troglitazone, but not BRL 49653, partially inhibit the induced expression of vascular cell adhesion molecule-1 (VCAM-1), as measured by ELISA, and monocyte binding to human aortic endothelial cells (HAECs) activated by phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide. The "natural" PPAR activator 15d-PGJ(2) had the greatest potency and was the only tested molecule capable of partially inhibiting the induced expression of E-selectin and neutrophil-like HL60 cell binding to PMA-activated HAECs. Intracellular adhesion molecule-1 induction by PMA was unaffected by any of the molecules tested. Both PPAR-alpha and PPAR-gamma mRNAs were detected in HAECs by using reverse transcription-polymerase chain reaction and a ribonuclease protection assay; however, we have yet to determine which, if any, of the PPARs are mediating this process. These results suggest that certain PPAR activators may help limit chronic inflammation mediated by VCAM-1 and monocytes without affecting acute inflammation mediated by E-selectin and neutrophil binding.
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PMID:Peroxisome proliferator-activated receptor activators target human endothelial cells to inhibit leukocyte-endothelial cell interaction. 1047 50

The measurement of leukocyte rheology in vascular disease is a recent development with a wide range of new opportunities. The International Society of Clinical Hemorheology has asked an expert panel to propose guidelines for the investigation of leukocyte rheology in clinical situations. This article first discusses the mechanical, adhesive and related functional properties of leukocytes (especially neutrophils) which influence their circulation, and establishes the rationale for clinically-related measurements of parameters which describe them. It is concluded that quantitation of leukocyte adhesion molecules, and of their endothelial receptors may assist understanding of leukocyte behaviour in vascular disease, along with measurements of flow resistance of leukocytes, free radical production, degranulation and gene expression. For instance, vascular cell adhesion molecule (VCAM-1) is abnormally present on endothelial cells in atherosclerosis, diabetes mellitus and inflammatory conditions. Soluble forms of intercellular adhesion molecule (ICAM-1) or VCAM can be found elevated in the blood of patients with rheumatoid arthritis or infections disease. In the second part of the article, possible technical approaches are presented and possible avenues for leukocyte rheological investigations are discussed.
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PMID:Measurement of leukocyte rheology in vascular disease: clinical rationale and methodology. International Society of Clinical Hemorheology. 1051 84

Macrovascular complications are the most important causes of morbidity, mortality and disability in people with Type 2 diabetes mellitus. Although other known risk factors for macrovascular disease (e.g. dyslipidaemia, hypertension, obesity) often co-exist, diabetes itself is an important risk factor for accelerated development of atherosclerosis. Hyperglycaemia, hyperinsulinaemia and insulin resistance may each play a major role in the onset and development of atherosclerotic disease, which causes arterial wall dysfunction, haematological disturbances and lipid abnormalities through two mechanisms: oxidative stress and non-enzymatic glycation. Hyperglycaemia induces damage to the endothelium through activation of mitogen-activated protein kinase, protein kinase C and transcription factor nuclear factor (NF)-kappaB and through increased levels of pro-adhesion proteins such as intracellular adhesion molecule (ICAM)-1. The arterial wall tone is shifted towards vasoconstriction by hyperglycaemia, which is also associated with vascular smooth muscle cell proliferation and increased intimal wall thickness. Alteration of the coagulation system towards thrombophilia is observed in Type 2 diabetes and a series of lipid abnormalities that facilitate the development of atherosclerosis is evident. In Type 2 diabetes, undiagnosed disease and unrecognized postprandial hyperglycaemia are becoming the most relevant issues in reducing the risk of vascular complications and cardiovascular mortality; improved glycaemic control may reduce the incidence of macrovascular complications.
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PMID:Cardiovascular risk factors in type 2 diabetes: the role of hyperglycaemia. 1052 35


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