scholarly journals Oxidized low-density lipoprotein induces the expression of P-selectin (GMP140/PADGEM/CD62) on human endothelial cells

1995 ◽  
Vol 306 (1) ◽  
pp. 293-298 ◽  
Author(s):  
V Gebuhrer ◽  
J F Murphy ◽  
J C Bordet ◽  
M P Reck ◽  
J L McGregor
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Mononuclear Cells ◽  
Umbilical Vein ◽  
Oxidized Ldl ◽  
Low Density ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Ldl Particles ◽  
High Concentrations

It is now well established that monocytes adhere to endothelial cells activated by oxidized low-density lipoproteins (LDL). However, the adhesive receptors on endothelial cells involved in binding monocytes, following an insult by oxidized LDL, remains to be elucidated. In this study we have looked at the effect of native or oxidized LDL on the expression of P-selectin. Native LDL (N-LDL) was oxidized by incubation with either endothelial cells (EC-LDL) or copper (Cu-LDL), or in culture medium as a control (C-LDL). Expression of P-selectin was assayed with an anti-P-selectin (CD62) monoclonal antibody (LYP20). Results show that EC-LDL and Cu-LDL, but not N-LDL or C-LDL, induce the expression of P-selectin by human umbilical-vein endothelial cells (HUVECs). Induction of P-selectin by low concentrations (20 micrograms/ml) of LDL is directly related to the state of oxidation of the LDL particles. In addition, high concentrations (100 micrograms/ml) of N-LDL also activate HUVECs by inducing P-selectin expression. This expression was sustained for a period of over 1 h on LDL-activated endothelial cells, in contrast with thrombin- or histamine-activated endothelial cells, whose P-selectin levels fall within 15-20 min after induction. E-selectin, in contrast with P-selectin, could not be induced by endothelial cells treated with low or high concentrations of oxidized LDL. Results in this study show that P-selectin expressed by oxidized-LDL-treated endothelial cells are involved in mediating the adhesion of a monocytic cell line (U937) or monocytes in peripheral-blood mononuclear cells. An anti-P-selectin monoclonal antibody (LYP20) inhibited the binding of U937 cells and monocytes. These results strongly suggest that P-selectin is involved in the early stages of atherogenesis.

scholarly journals Lipopolysaccharide Activates Caspase-1 (Interleukin-1–Converting Enzyme) in Cultured Monocytic and Endothelial Cells

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 577-584 ◽  
Author(s):  
Ralf R. Schumann ◽  
Claus Belka ◽  
Dirk Reuter ◽  
Norbert Lamping ◽  
Carsten J. Kirschning ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Cysteine Proteases ◽  
Precursor Protein ◽  
Converting Enzyme ◽  
Blood Monocytes ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Caspase 1

Abstract Interleukin-1β (IL-1β) is a pleiotropic proinflammatory cytokine. Mechanisms leading to its secretion include not only release of newly synthesized protein, but also cleavage of a preformed immature precursor protein into an active secretory form by the intracellular protease caspase-1 (formerly termed IL-1–converting enzyme [ICE]). Caspase-1 belongs to a rapidly growing family of cysteine proteases with substrate specificity for aspartate involved in cellular apoptosis. We have used an assay determining the caspase-1 activity based on cleavage of a fluorogenic peptide substrate to elucidate its role in lipopolysaccharide (LPS)-induced secretion of IL-1β. We show that LPS induces moderate caspase-1 activity in the monocytic cell line THP-1, in freshly isolated peripheral blood monocytes, and in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent fashion. Caspase-1 activation by LPS was associated with cleavage of the IL-1β precursor protein that was followed by release of the mature IL-1β protein in monocytic cells. In contrast, subsequent release of IL-1β by HUVECs was not significant. LPS-induced caspase-1 activation appeared not to result from modulation of caspase-1 transcript accumulation and inhibition of caspase-1 activity was accomplished by two specific inhibitors, YVAD-CHO and YVAD-CMK, capable of alleviating the release of mature IL-1β. Taken together, these results show that LPS moderately activates caspase-1 and that caspase-1 activation contributes to LPS induction of IL-1β secretion.

scholarly journals Glucosyltransferases of Viridans Group Streptococci Modulate Interleukin-6 and Adhesion Molecule Expression in Endothelial Cells and Augment Monocytic Cell Adherence

2006 ◽  
Vol 74 (2) ◽  
pp. 1273-1283 ◽  
Author(s):  
Chiou-Yueh Yeh ◽  
Jen-Yang Chen ◽  
Jean-San Chia
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecules ◽  
Interleukin 6 ◽  
Umbilical Vein ◽  
Mitogen Activated Protein Kinase ◽  
Free Form ◽  
Dependent Manner ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Viridans Group Streptococci

ABSTRACT Recruitment of monocytes plays important roles during vegetation formation and endocardial inflammation in the pathogenesis of infective endocarditis (IE). Bacterial antigens or modulins can activate endothelial cells through the expression of cytokines or adhesion molecules and modulate the recruitment of leukocytes. We hypothesized that glucosyltransferases (GTFs), modulins of viridans group streptococci, may act directly to up-regulate the expression of adhesion molecules and also interleukin-6 (IL-6) to augment monocyte attachment to endothelial cells. Using primary cultured human umbilical vein endothelial cells (HUVECs) as an in vitro model, we demonstrated that GTFs (in the cell-bound or free form) could specifically modulate the expression of IL-6, and also adhesion molecules, in a dose- and time-dependent manner. Results of inhibition assays suggested that enhanced expression of adhesion molecules was dependent on the activation of nuclear factor κB (NF-κB) and extracellular signal-regulated kinase and that p38 mitogen-activated protein kinase pathways also contributed to the release of IL-6. Streptococcus-infected HUVECs or treatment with purified IL-6 plus soluble IL-6 receptor α enhanced the expression of ICAM-1 and the adherence of the monocytic cell line U937. These results suggest that streptococcal GTFs might play an important role in recruiting monocytic cells during inflammation in IE through induction of adhesion molecules and IL-6, a cytokine involved in transition from neutrophil to monocyte recruitment.

scholarly journals Two sites on P-selectin (the lectin and epidermal growth factor-like domains) are involved in the adhesion of monocytes to thrombin-activated endothelial cells

1994 ◽  
Vol 303 (2) ◽  
pp. 619-624 ◽  
Author(s):  
J F Murphy ◽  
J L McGregor
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mononuclear Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Activated Platelets ◽  
Epidermal Growth

P-selectin, also known as GMP-140, PADGEM or CD62, is expressed on the surface of thrombin-activated platelets and endothelial cells (EC). It is a member of the selectin family of adhesion molecules that regulate leucocyte interactions with the blood vessel wall. In this study we have found that peptides derived from both the lectin (residues 19-34 and 51-61) and epidermal growth factor (EGF)-like (residues 127-139) domains inhibit the adhesion of peripheral blood mononuclear cells (PBMC), elutriated monocytes and a monocytic cell line (U937) to thrombin-activated EC. This inhibition occurred in a concentration-dependent manner and the peptide most active at the lowest concentrations was the one derived from the EGF-like motif (127-139). The scrambled forms of these peptides, identical in amino acid composition to the authentic peptides but with altered sequences, were not inhibitory. Thrombin-activated platelets supported adhesion of U937 cells and this adhesion was dramatically inhibited by the two peptides derived from the lectin-like domain (residues 19-34 and 51-61). All three peptides, when conjugated to BSA and coated on plastic plates, mediated U937 cell adhesion. This study shows, for the first time, that two sites on P-selectin, the lectin and EGF-like domains, are involved in the adhesion of monocytes to thrombin-activated EC.

scholarly journals Lipopolysaccharide Activates Caspase-1 (Interleukin-1–Converting Enzyme) in Cultured Monocytic and Endothelial Cells

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 577-584 ◽  
Author(s):  
Ralf R. Schumann ◽  
Claus Belka ◽  
Dirk Reuter ◽  
Norbert Lamping ◽  
Carsten J. Kirschning ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Cysteine Proteases ◽  
Precursor Protein ◽  
Converting Enzyme ◽  
Blood Monocytes ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Caspase 1

Interleukin-1β (IL-1β) is a pleiotropic proinflammatory cytokine. Mechanisms leading to its secretion include not only release of newly synthesized protein, but also cleavage of a preformed immature precursor protein into an active secretory form by the intracellular protease caspase-1 (formerly termed IL-1–converting enzyme [ICE]). Caspase-1 belongs to a rapidly growing family of cysteine proteases with substrate specificity for aspartate involved in cellular apoptosis. We have used an assay determining the caspase-1 activity based on cleavage of a fluorogenic peptide substrate to elucidate its role in lipopolysaccharide (LPS)-induced secretion of IL-1β. We show that LPS induces moderate caspase-1 activity in the monocytic cell line THP-1, in freshly isolated peripheral blood monocytes, and in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent fashion. Caspase-1 activation by LPS was associated with cleavage of the IL-1β precursor protein that was followed by release of the mature IL-1β protein in monocytic cells. In contrast, subsequent release of IL-1β by HUVECs was not significant. LPS-induced caspase-1 activation appeared not to result from modulation of caspase-1 transcript accumulation and inhibition of caspase-1 activity was accomplished by two specific inhibitors, YVAD-CHO and YVAD-CMK, capable of alleviating the release of mature IL-1β. Taken together, these results show that LPS moderately activates caspase-1 and that caspase-1 activation contributes to LPS induction of IL-1β secretion.

Protective effects of soy-isoflavones in cardiovascular disease

2008 ◽  
Vol 28 (01/02) ◽  
pp. 85-88 ◽  
Author(s):  
D. Fuchs ◽  
H. Daniel ◽  
U. Wenzel
Keyword(s):  
Cardiovascular Disease ◽  
Endothelial Cells ◽  
Molecular Mechanisms ◽  
Dietary Intervention ◽  
Mononuclear Cells ◽  
Oxidized Ldl ◽  
Proteome Analysis ◽  
Soy Isoflavones ◽  
Protective Effects ◽  
Estrogen Production

SummaryEpidemiological studies indicate that the consumption of soy-containing food may prevent or slow-down the development of cardiovascular disease. In endothelial cells application of a soy extract or a combination of the most abundant soy isoflavones genistein and daidzein both inhibited apoptosis, a driving force in atherosclerosis development, when applied in combination with oxidized LDL or homocysteine. Proteome analysis revealed that the stressorinduced alteration of protein expression profile was reversed by the soy extract or the genistein/daidzein mixture. Only few protein entities that could be functionally linked to mitochondrial dysfunction were regulated in common by both application forms of isoflavones. A dietary intervention with isoflavone-enriched soy extract in postmenopausal women, who generally show strongly increased cardiovascular risk due to diminished estrogen production, led to significant alterations in the steady state levels of proteins from mononuclear blood cells. The proteins identified by proteome analysis revealed that soy isoflavones may increase the anti-inflammatory response in blood mononuclear cells thereby contributing to the atherosclerosispreventive activities of a soy-rich diet. Conclusion: By proteome analysis protein targets were identified in vitro in endothelial cells that respond to soy isoflavones and that may decipher molecular mechanisms through which soy products exert their protective effects in the vasculature.

Oxidized low-density lipoprotein and 15-deoxy-Δ12,14-PGJ2 increase mitochondrial complex I activity in endothelial cells

2003 ◽  
Vol 285 (6) ◽  
pp. H2298-H2308 ◽  
Author(s):  
Erin K. Ceaser ◽  
Anup Ramachandran ◽  
Anna-Liisa Levonen ◽  
Victor M. Darley-Usmar
Keyword(s):  
Endothelial Cells ◽  
Complex I ◽  
Citrate Synthase ◽  
Umbilical Vein ◽  
Oxidized Ldl ◽  
Antioxidant Defenses ◽  
Oxidized Lipids ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Complex I Activity

Oxidized lipids are capable of initiating diverse cellular responses through both receptor-mediated mechanisms and direct posttranslational modification of proteins. Typically, exposure of cells to low concentrations of oxidized lipids induces cytoprotective pathways, whereas high concentrations result in apoptosis. Interestingly, mitochondria can contribute to processes that result in either cytoprotection or cell death. The role of antioxidant defenses such as glutathione in adaptation to stress has been established, but the potential interaction with mitochondrial function is unknown and is examined in this article. Human umbilical vein endothelial cells (HUVEC) were exposed to oxidized LDL (oxLDL) or the electrophilic cyclopentenone 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2). We demonstrate that complex I activity, but not citrate synthase or cytochrome- c oxidase, is significantly induced by oxLDL and 15d-PGJ2. The mechanism is not clear at present but is independent of the induction of GSH, peroxisome proliferator-activated receptor (PPAR)-γ, and PPAR-α. This response is dependent on the induction of oxidative stress in the cells because it can be prevented by nitric oxide, probucol, and the SOD mimetic manganese(III) tetrakis(4-benzoic acid) porphyrin chloride. This increased complex I activity appears to contribute to protection against apoptosis induced by 4-hydroxynonenal.

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