Search results for "Endothelium."
showing 10 items of 748 documents
Abacavir and didanosine induce the interaction between human leukocytes and endothelial cells through Mac-1 upregulation
2010
Objective: Abacavir and didanosine are nucleoside reverse transcriptase inhibitors (NRTI) widely used in therapy for HIV-infection but which have been linked to cardiovascular complications. The objective of this study was to analyze the effects of clinically relevant doses of abacavir and didanosine on human leukocyte―endothelium interactions and to compare them with those of other NRTIs. Design and methods: The interactions between human leukocytes ― specifically peripheral blood polymorphonuclear (PMN) or mononuclear (PBMC) cells ― and human umbilical vein endothelial cells were evaluated in a flow chamber system that reproduces conditions in vivo. The expression of adhesion molecules wa…
Differential regulation of endothelial cell adhesion molecule expression by nitric oxide donors and antioxidants.
1998
Although nitric oxide (NO) and antioxidants inhibit adhesion molecule expression, their inhibitory effects on nuclear factor kappaB (NF-kappaB) activation may differ. The NO donors, but not 8-bromo-cGMP, decreased tumor necrosis factor alpha (TNF-alpha)-induced VCAM-1, ICAM-1, and E-selectin expression by 11-70%. In contrast, NAC completely abolished VCAM-1 and E-selectin expression and decreased ICAM-1 expression by 56%. Gel shift assays demonstrate that NF-kappaB activation was inhibited by both NO and antioxidants. The activation of NF-kappaB involves the phosphorylation and degradation of its cytoplasmic inhibitor IkappaB-alpha by 26S proteasomes. The 26S proteasome inhibitor MG132 prev…
Differential effects of anti-TNF-α and anti-IL-12/23 agents on human leukocyte–endothelial cell interactions
2015
AbstractEnhanced leukocyte recruitment is an inflammatory process that occurs during early phases of the vascular dysfunction that characterises atherosclerosis. We evaluated the impact of anti-TNF-α (adalimumab, infliximab and etanercept) and anti-IL-12/23 (ustekinumab) on interactions between human leukocytes and endothelial cells in a flow chamber that reproduced in vivo conditions. Clinical concentrations of anti-TNF-α were evaluated on the leukocyte recruitment induced by a variety of endothelial (TNF-α, interleukin-1β, lymphotoxin-α and angiotensin-II) and leukocyte (PAF, IL-12 and IL-23) stimuli related to inflammation and atherosclerosis. Treatment with anti-TNF-α, even before or af…
Endothelial Dysfunction and Inflammation in Ischemic Stroke Pathogenesis
2020
: Stroke is a heterogeneous disease, and within the broad category of brain ischemia and its subtypes vary dramatically in its etiology. : The endothelium can regulate the vascular homeostasis by modulating processes of vascular dilation and constriction by producing and secreting cytokines and chemical mediators, and inflammation represents one of the most important factors that contribute to alteration in vessel structure and function by dysregulation of this fine balance. : Endothelial dysfunction means a basic determinant of the vascular damage, which can be identified in all different clinical subtypes of stroke, and, recently, it has been recognized as an interesting determinant of c…
E-selectin modulates the malignant properties of T84 colon carcinoma cells.
2002
The extravasation of metastatic cells is regulated by molecular events involving the initial adhesion of tumor cells to the endothelium and subsequently the migration of cells in the host connective tissue. E-selectin on endothelial cells and sialyl Lewis X carbohydrate component on tumor cells are mainly involved in the adhesion of colon carcinoma cells to the endothelium of target organ. Interaction of T84 colon cancer cells to purified E-selectin in vitro caused an increase in the tyrosine phosphorylation of a number of proteins as well as the modulation of cellular properties correlated to the metastatic phenotype. Specifically, E-selectin-stimulated actin reorganization, increased coll…
Lymphatic endothelial progenitors bud from the cardinal vein and intersomitic vessels in mammalian embryos.
2012
Abstract The lymphatic vasculature preserves tissue fluid balance by absorbing fluid and macromolecules and transporting them to the blood vessels for circulation. The stepwise process leading to the formation of the mammalian lymphatic vasculature starts by the expression of the gene Prox1 in a subpopulation of blood endothelial cells (BECs) on the cardinal vein (CV) at approximately E9.5. These Prox1-expressing lymphatic endothelial cells (LECs) will exit the CV to form lymph sacs, primitive structures from which the entire lymphatic network is derived. Until now, no conclusive information was available regarding the cellular processes by which these LEC progenitors exit the CV without co…
Antibodies to proteinase 3 increase adhesion of neutrophils to human endothelial cells
1993
SUMMARY The detection of anti-neutrophil cytoplasmic antibodies (ANCA), especially those with specificity for proteinase 3, is important in the diagnosis and in monitoring disease activity of Wegener's granulomatosis and related vasculitides. An ubiquitous feature of all ANCA-associated acute vascular injury is lytic necrosis. Adhesion of neutrophils to endothelium is a fundamental early step of the inflammatory response. Recently we were able to show that ANCA recognize their target antigen (proteinase 3) translocated into the membrane of human endothelial cells. The aim of this study was to investigate the effect of ANCA on the adhesion of neutrophils to human endothelial cells. Incubatio…
Synthesis and biological activity of novel sialyl-lewisX conjugates
1996
Abstract Novel sialyl Lewis X conjugates have been synthesized and evaluated as inhibitors of E- and P-selectin mediated cell adhesion in cell culture assays. The most potent conjugate in the static inhibition assays exhibited a significant and dose-dependent pharmacological potency as inhibitor of the edotoxin-induced leukocyte adhesion to the endothelium of postcapillary venules in rats.
Anti-inflammatory properties of simvastatin on leukocyte-endothelial cell interactions following hemorrhagic shock
2002
Background Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to lower serum cholesterol levels. Recent studies reported that statins have vasculoprotective effects independent of their cholesterol-lowering properties. We studied simvastatin for its ability to modulate leukocyte-endothelial cell interactions under acute inflammation following hemorrhage and reperfusion. Methods The effects of simvastatin on leukocyte-endothelial cell interactions were observed by intravital microscopy in the rat mesenteric microcirculation and by immunohistochemical analyzes. Simvastatin (50 μg/kg or 100 μg/kg) was administrated intraperitoneally 18 h before study. Inf…
The pleiotropic effects of antiplatelet therapies
2019
Percutaneous coronary intervention is the most often used method for coronary revascularization. Stenting restores blood perfusion to ischemic areas, but it also causes mechanical disruption of the atheromatous plaque and the nearby endothelium, stimulating the activation of platelets. In a similar way, platelets are activated by thrombin exposure in the setting of plaque rupture. The interaction between platelets, oxidative stress and inflammation is an important factor determining the extent and severity of vascular dysfunction observed in these settings. Platelets activated by the vessel trauma release inflammatory and mitogenic mediators into the vascular microenvironment, activating le…