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 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.

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 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.

Expression of human endothelin-converting enzyme isoforms: role of angiotensin IIThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.

2008 ◽  
Vol 86 (6) ◽  
pp. 299-309 ◽  
Author(s):  
W. Goettsch ◽  
A. Schubert ◽  
H. Morawietz
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Umbilical Vein ◽  
Artery Bypass ◽  
Control Group ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Mammary Arteries ◽  
Endothelin Converting Enzyme ◽  
Internal Mammary

A key step in endothelin-1 (ET-1) synthesis is the proteolytic cleavage of big ET-1 by the endothelin-converting enzyme-1 (ECE-1). Four alternatively spliced isoforms, ECE-1a to ECE-1d, have been discovered; however, regulation of the expression of specific ECE-1 isoforms is not well understood. Therefore, we stimulated primary human umbilical vein endothelial cells (HUVECs) with angiotensin II (Ang II). Furthermore, expression of ECE-1 isoforms was determined in internal mammary arteries of patients undergoing coronary artery bypass grafting surgery. Patients had received one of 4 therapies: angiotensin-converting enzyme inhibitors (ACE-I), Ang II type 1 receptor blockers (ARB), HMG-CoA reductase inhibitors (statins), and a control group that had received neither ACE-I, ARB (that is, treatment not interfering in the renin–angiotensin system), nor statins. Under control conditions, ECE-1a is the dominant isoform in HUVECs (4.5 ± 2.8 amol/μg RNA), followed by ECE-1c (2.7 ± 1.0 amol/μg), ECE-1d (0.49 ± 0.17 amol/μg), and ECE-1b (0.17 ± 0.04 amol/μg). Stimulation with Ang II did not change the ECE-1 expression pattern or the ET-1 release. We found that ECE-1 mRNA expression was higher in patients treated with statins than in patients treated with ARB therapy (5.8 ± 0.76 RU versus 3.0 ± 0.4 RU), mainly attributed to ECE-1a. In addition, ECE-1a mRNA expression was higher in patients receiving ACE-I therapy than in patients receiving ARB therapy (1.68 ± 0.27 RU versus 0.83 ± 0.07 RU). We conclude that ECE-1a is the major ECE-1 isoform in primary human endothelial cells. Its expression in internal mammary arteries can be regulated by statin therapy and differs between patients with ACE-I and ARB therapy.

Syndecan-4-dependent signaling in the inhibition of endotoxin-induced endothelial adherence of neutrophils by antithrombin

2003 ◽  
Vol 90 (12) ◽  
pp. 1150-1157 ◽  
Author(s):  
Nicole Kaneider ◽  
Ellen Förster ◽  
Birgit Mosheimer ◽  
Daniel Sturn ◽  
Christian Wiedermann
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Human Neutrophils ◽  
Heparin Binding ◽  
Clotting Factors ◽  
Edema Formation ◽  
Granulocyte Elastase ◽  
Umbilical Vein Endothelial Cells ◽  
Static Conditions

SummaryCirculating endotoxin is elevated in sepsis and plays a role in endothelial dysfunction whereas antithrombin is decreased by virtue of its consumption during complex formation with clotting factors and by proteolytic degradation by granulocyte elastase. Dysfunction of endothelium results in enhanced leukocyte rolling and diapedesis into tissues leading to edema formation and injury. Antithrombin exerts beneficial effects on endothelial function in sepsis. A direct anti-inflammatory action of anti-thrombin in inflammatory cells is exerted via heparan sulfate proteoglycans. In this study, we investigated whether antithrom-bin affects endotoxin-induced adhesion of neutrophils to human endothelial cells in vitro and whether glycosaminoglycans are involved in its signaling. Adhesion of human neutrophils to monolayers of umbilical vein endothelial cells was tested under static conditions. Endothelial cells were pretreated with endotoxin, interleukin-1, heparinase-I, chondroitinase-ABC or anti-syndecan-4-antibody. Endotoxin and interleukin-1 increased neutrophil adherence to human umbilical vein endothelial cells which was inhibited by antithrombin. Concomitant incubation with pentasaccharide abolished this effect of antithrombin. Treatment of endothelial cells with heparinase or chondroitinase led to higher adhesion and prevented effects of antithrom-bin. With antibodies to syndecan-4, enhanced adhesion of neutrophils was observed. As studied by Western blotting, endo-toxin-induced signaling was diminished by antithrombin and the effect was reversible by chondroitinase or heparinase. From our results, we can conclude that endotoxin-induced adhesion of leukocytes to endothelium can be reversed by ligation of syndecan-4 with antithrombin´s heparin-binding site and interferences with stress response signaling events in endothelium.

Induction of ICAM-1 by TNF-alpha, IL-1 beta, and LPS in human endothelial cells after downregulation of PKC

1992 ◽  
Vol 263 (4) ◽  
pp. C767-C772 ◽  
Author(s):  
C. L. Myers ◽  
S. J. Wertheimer ◽  
J. Schembri-King ◽  
T. Parks ◽  
R. W. Wallace
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Protein Kinase Inhibitors ◽  
Intercellular Adhesion Molecule ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Western Blots ◽  
Mrna Induction

The intercellular adhesion molecule 1 (ICAM-1) is induced on endothelial cells by tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and lipopolysaccharide (LPS). We have reported the sensitivity of cytokine-induced ICAM-1 expression to protein kinase inhibitors, including inhibitors of protein kinase C (PKC) [C. L. Myers, S. N. Desai, J. Schembri-King, G. L. Letts, and R. W. Wallace. Am. J. Physiol. 262 (Cell Physiol. 31): C365-C373, 1992]. To directly investigate the role of PKC in ICAM-1 induction, we downregulated PKC by pretreatment of human umbilical vein endothelial cells with phorbol 12-myristate 13-acetate (PMA) and assessed ICAM-1 protein and mRNA induction elicited by subsequent exposure to inflammatory stimuli. PMA treatment results in ICAM-1 protein induction that declines to basal levels by 3 days. Western blots of endothelial cell lysates reveal a nearly complete loss of immunologically reactive PKC. Subsequent activation with cytokine or LPS leads to reinduction of ICAM-1 protein and mRNA; however, the cells no longer produced substantial amounts of ICAM-1 protein or mRNA in response to PMA stimulation. Cross desensitization is observed with phorbol dibutyrate, while 4 alpha-phorbol has no desensitizing effect. The data indicate that PKC activation, while capable of inducing ICAM-1 expression, is not essential for ICAM-1 induction by the inflammatory mediators TNF-alpha, IL-1 beta, or LPS.

Analysis of tight junctions during neutrophil transendothelial migration

2000 ◽  
Vol 113 (1) ◽  
pp. 45-57 ◽  
Author(s):  
A.R. Burns ◽  
R.A. Bowden ◽  
S.D. MacDonell ◽  
D.C. Walker ◽  
T.O. Odebunmi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junctions ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Intercellular Junctions ◽  
Barrier Properties ◽  
Transendothelial Migration ◽  
Immunoblot Analysis ◽  
Intimate Contact ◽  
And Migration

Intercellular junctions have long been considered the main sites through which adherent neutrophils (PMNs) penetrate the endothelium. Tight junctions (TJs; zonula occludens) are the most apical component of the intercellular cleft and they form circumferential belt-like regions of intimate contact between adjacent endothelial cells. Whether PMN transmigration involves disruption of the TJ complex is unknown. We report here that endothelial TJs appear to remain intact during PMN adhesion and transmigration. Human umbilical vein endothelial cell (HUVEC) monolayers, a commonly used model for studying leukocyte trafficking, were cultured in astrocyte-conditioned medium to enhance TJ expression. Immunofluorescence microscopy and immunoblot analysis showed that activated PMN adhesion to resting monolayers or PMN migration across interleukin-1-treated monolayers does not result in widespread proteolytic loss of TJ proteins (ZO-1, ZO-2, and occludin) from endothelial borders. Ultrastructurally, TJs appear intact during and immediately following PMN transendothelial migration. Similarly, transendothelial electrical resistance is unaffected by PMN adhesion and migration. Previously, we showed that TJs are inherently discontinuous at tricellular corners where the borders of three endothelial cells meet and PMNs migrate preferentially at tricellular corners. Collectively, these results suggest that PMN migration at tricellular corners preserves the barrier properties of the endothelium and does not involve widespread disruption of endothelial TJs.

scholarly journals Interleukin-1, tumor necrosis factor, and the production of colony- stimulating factors by cultured mesenchymal cells

Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1316-1323 ◽  
Author(s):  
CA Sieff ◽  
CM Niemeyer ◽  
SJ Mentzer ◽  
DV Faller
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Messenger Rna ◽  
Tumor Necrosis ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Mesenchymal Cells ◽  
Colony Stimulating Factors ◽  
Gm Csf ◽  
Necrosis Factor

Abstract Although the genes for four hematopoietic colony-stimulating factors (CSFs) have been cloned, neither the mechanism of the regulation of their production nor their cellular origins have been established with certainty. Monocytes are known to produce colony-stimulating and burst- promoting activities, as well as several monokines such as interleukin- 1 (IL-1) and tumor necrosis factor (TNF). These monokines indirectly stimulate other mesenchymal cells to produce certain colony-stimulating factors such as granulocyte-macrophage CSF (GM-CSF). To determine whether monocytes produce other CSFs and if so, to compare the mechanism of regulation of production with that of endothelial cells and fibroblasts, we investigated the synthesis of CSFs by monocytes, human umbilical vein endothelial cells, and fibroblasts. We used total cellular RNA blot analysis to determine interleukin-3 (IL-3), GM-CSF, granulocyte CSF (G-CSF), and monocyte CSF (M-CSF) messenger RNA (mRNA) content and immunoprecipitation or bioassay to confirm the presence of the specific secreted proteins. The results indicate that M-CSF mRNA and protein are produced constitutively by all three cell types and their level of expression does not increase after induction. In contrast, GM-CSF and G-CSF mRNAs are barely detectable in uninduced monocytes and show an increase in expression after lipopolysaccharide treatment. Retrovirus-immortalized endothelial cells, unlike primary endothelial cells or both primary and immortalized fibroblasts, produce IL-1 constitutively; this correlates with their constitutive production of GM-CSF and G-CSF. IL-3 mRNA was not detectable in any of these cells either before or after induction. The results indicate that these mesenchymal cells can produce three CSFs: GM-CSF, G-CSF, and M-CSF; furthermore, the data suggest that the mechanism of regulation of M-CSF production is different from that of GM-CSF and G-CSF, and that the latter two inducible CSFs are regulated by different factors in monocytes compared with the other mesenchymal cells.

INHIBITION OF ENDOTHELIAL CELL PROLIFERATION BY NORMAL HUMAN MONOCYTES

1987 ◽  
Author(s):  
F Liote ◽  
M P Wautier ◽  
E Savariau ◽  
H Setiadi ◽  
J L Wautier
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
Thymidine Uptake ◽  
Blood Monocytes ◽  
Fibronectin Receptor

Human peripheral blood monocytes and macrophages possess factors which are capable of inhibiting or stimulating endothelial cell proliferation. We have further explored if such activity is due to cytotoxic effects of monocytes. Normal mononuclear cells were isolated first by density gradient. Monocytes were then purified by three different techniques: 1) counter centrifugation elutriation (CCE) (Beckman) 2) selective adhesion to gelatin-plasma (GPI) 3) selective adhesion to fibronectin (Fn). Cytotoxicity was estimated by counting the release of 51cr used to label the human umbilical vein endothelial cells (HUVE) prior to the addition of monocytes. Whilst [3H] thymidine incorporation by HUVE permitted us to measure the effect of monocytes on the growth of the endothelial cells. Monocytes were incubated with HUVE (12×103) for 24 to 36h at various concentrations '(1.5-12×103). No cytotoxic effect could be demonstrated but an inhibition of [3h] thymidine uptake was observed and was dependent upon monocytes concentration. Monocytes isolated on GP1 exhibited a significantly higher inhibitory effect (p<0.05) compared to those purified on Fn or by CCE.(GP1: 85±6%, Fn:58±6%, CCE:67±5%). These results indicated t*hat normal monocytes can inhibit endothelial cell proliferation. This activity appeared to be higher when monocytes were isolated on GP1 which suggest that the adhesion on this surface could stimulate monocytes not only by its fibronectin receptor. This inhibitory activity of monocyte on endothelial cells proliferation could be different in patients with vascular disorders.

Sign in / Sign up

Export Citation Format

Share Document