scholarly journals An atherogenic stimulus homocysteine inhibits cofactor activity of thrombomodulin and enhances thrombomodulin expression in human umbilical vein endothelial cells

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2930-2936 ◽  
Author(s):  
T Hayashi ◽  
G Honda ◽  
K Suzuki
Keyword(s):  
Endothelial Cells ◽  
Total Protein ◽  
Protein Level ◽  
Umbilical Vein ◽  
Mrna Level ◽  
Fold Increase ◽  
Immunoblot Analysis ◽  
Whole Cells ◽  
Total Protein Level ◽  
Cofactor Activity

Abstract Thrombomodulin plays a role as a cofactor for thrombin-catalyzed activation of protein C on endothelial cells. We examined the effect of homocysteine, a stimulant of atherosclerosis and thrombotic disease, on the cofactor activity and protein level of thrombomodulin and also on the expression of thrombomodulin in endothelial cells. Homocysteine inhibited the cofactor activity of thrombomodulin both on the surface of endothelial cells and in the whole cells dose- and time-dependently, and maximal inhibition of the cofactor activity occurred after a 3- to 6-hour incubation with 10 mmol/L homocysteine (10% of initial activity). Homocysteine also decreased the amount of intact (unreduced) thrombomodulin in endothelial cells. However, at the same condition the total protein level (reduced and unreduced form) of thrombomodulin, determined by dot immunoblot analysis using the monoclonal antibody that recognized both reduced and unreduced thrombomodulin, decreased slightly, and the mRNA level of thrombomodulin showed a twofold to three-fold increase. After 24 hours of incubation, the cofactor activity and total protein level of thrombomodulin were 60% and 165% of the initial values, respectively. When purified thrombomodulin fixed to a microwell plate was treated with homocysteine, both cofactor activity and thrombin-binding ability to the thrombomodulin were decreased in proportion to the concentration of homocysteine. These findings suggest that homocysteine directly inhibited the cofactor activity of thrombomodulin on endothelial cells by reducing the disulfide-bond rich epidermal growth factor-like structures of thrombomodulin. This would a result in the decrease of the antithrombotic property of endothelium and may also trigger off the synthesis of mRNA and protein of thrombomodulin to maintain the antithrombotic properties of the cells.

scholarly journals An atherogenic stimulus homocysteine inhibits cofactor activity of thrombomodulin and enhances thrombomodulin expression in human umbilical vein endothelial cells

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2930-2936 ◽  
Author(s):  
T Hayashi ◽  
G Honda ◽  
K Suzuki
Keyword(s):  
Endothelial Cells ◽  
Total Protein ◽  
Protein Level ◽  
Umbilical Vein ◽  
Mrna Level ◽  
Fold Increase ◽  
Immunoblot Analysis ◽  
Whole Cells ◽  
Total Protein Level ◽  
Cofactor Activity

Thrombomodulin plays a role as a cofactor for thrombin-catalyzed activation of protein C on endothelial cells. We examined the effect of homocysteine, a stimulant of atherosclerosis and thrombotic disease, on the cofactor activity and protein level of thrombomodulin and also on the expression of thrombomodulin in endothelial cells. Homocysteine inhibited the cofactor activity of thrombomodulin both on the surface of endothelial cells and in the whole cells dose- and time-dependently, and maximal inhibition of the cofactor activity occurred after a 3- to 6-hour incubation with 10 mmol/L homocysteine (10% of initial activity). Homocysteine also decreased the amount of intact (unreduced) thrombomodulin in endothelial cells. However, at the same condition the total protein level (reduced and unreduced form) of thrombomodulin, determined by dot immunoblot analysis using the monoclonal antibody that recognized both reduced and unreduced thrombomodulin, decreased slightly, and the mRNA level of thrombomodulin showed a twofold to three-fold increase. After 24 hours of incubation, the cofactor activity and total protein level of thrombomodulin were 60% and 165% of the initial values, respectively. When purified thrombomodulin fixed to a microwell plate was treated with homocysteine, both cofactor activity and thrombin-binding ability to the thrombomodulin were decreased in proportion to the concentration of homocysteine. These findings suggest that homocysteine directly inhibited the cofactor activity of thrombomodulin on endothelial cells by reducing the disulfide-bond rich epidermal growth factor-like structures of thrombomodulin. This would a result in the decrease of the antithrombotic property of endothelium and may also trigger off the synthesis of mRNA and protein of thrombomodulin to maintain the antithrombotic properties of the cells.

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.

Shear stress increases endothelial platelet-derived growth factor mRNA levels

1991 ◽  
Vol 260 (2) ◽  
pp. H642-H646 ◽  
Author(s):  
H. J. Hsieh ◽  
N. Q. Li ◽  
J. A. Frangos
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Platelet Derived Growth Factor ◽  
Mrna Levels ◽  
Cell Mitogen ◽  
Stress Dependent

We have investigated the effect of shear stress on platelet-derived growth factor (PDGF) A and B chain mRNA levels in cultured human umbilical vein endothelial cells (hUVEC). The levels of both PDGF A and B mRNA in hUVEC were increased by a physiological shear stress (16 dyn/cm2), reaching a maximum approximately 1.5-2 h after the onset of shear stress and returning almost to control values at 4 h. The peak levels showed a more than 10-fold enhancement for PDGF A mRNA and a 2- to 3-fold increase for PDGF B mRNA (P less than 0.05). PDGF A mRNA also showed a shear-dependent increase from 0 to 6 dyn/cm2 (P less than 0.05) and then plateaued from 6 to 51 dyn/cm2. PDGF B mRNA levels were elevated as shear stress increased from 0 to 6 dyn/cm2 then declined gradually to a minimum at 31 dyn/cm2 (P less than 0.05) and increased again when shear stress rose to 51 dyn/cm2 (P less than 0.05). PDGF, a potent smooth muscle cell mitogen and vasoconstrictor, released from the endothelium may regulate the blood flow in vivo. The shear stress-dependent elevation of PDGF A and B mRNA in endothelial cells may be involved in the adaptation of blood vessels to flow mediated by the endothelium.

scholarly journals Thrombin Stimulation of the Vascular Cell Adhesion Molecule-1 Promoter in Endothelial Cells Is Mediated by Tandem Nuclear Factor-κB and GATA Motifs

2001 ◽  
Vol 276 (50) ◽  
pp. 47632-47641 ◽  
Author(s):  
Takashi Minami ◽  
William C. Aird
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Response Element ◽  
Vascular Adhesion ◽  
Stimulation Of

The goal of this study was to delineate the transcriptional mechanisms underlying thrombin-mediated induction of vascular adhesion molecule-1 (VCAM-1). Treatment of human umbilical vein endothelial cells with thrombin resulted in a 3.3-fold increase in VCAM-1 promoter activity. The upstream promoter region of VCAM-1 contains a thrombin response element, two nuclear factor κB (NF-κB) motifs, and a tandem GATA motif. In transient transfection assays, mutation of the thrombin response element had no effect on thrombin induction. In contrast, mutation of either NF-κB site resulted in a complete loss of induction, whereas a mutation of the two GATA motifs resulted in a significant reduction in thrombin stimulation. In electrophoretic mobility shift assays, nuclear extracts from thrombin-treated endothelial cells displayed markedly increased binding to the tandem NF-κB and GATA motifs. The NF-κB complex was supershifted with anti-p65 antibodies, but not with antibodies to RelB, c-Rel, p50, or p52. The GATA complex was supershifted with antibodies to GATA-2, but not GATA-3 or GATA-6. A construct containing tandem copies of the VCAM-1 GATA motifs linked to a minimal thymidine kinase promoter was induced 2.4-fold by thrombin. Taken together, these results suggest that thrombin stimulation of VCAM-1 in endothelial cells is mediated by the coordinate action of NF-κB and GATA transcription factors.

scholarly journals Peroxisome Proliferator-Activated ReceptorγRegulates the Expression of Lipid Phosphate Phosphohydrolase 1 in Human Vascular Endothelial Cells

PPAR Research ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yazi Huang ◽  
Beilei Zhao ◽  
Yahan Liu ◽  
Nanping Wang
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Mrna Level ◽  
Site Directed Mutagenesis ◽  
Luciferase Reporter ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Lipid Phosphate ◽  
Lipid Phosphate Phosphohydrolase

Lipid phosphate phosphohydrolase 1 (LPP1), a membrane ectophosphohydrolase regulating the availability of bioactive lipid phosphates, plays important roles in cellular signaling and physiological processes such as angiogenesis and endothelial migration. However, the regulated expression of LPP1 remains largely unknown. Here, we aimed to examine a role of peroxisome proliferator-activated receptorγ(PPARγ) in the transcriptional control ofLPP1gene expression. In human umbilical vein endothelial cells (HUVECs), quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) demonstrated that activation of PPARγincreased the mRNA level of LPP1. Chromatin immunoprecipitation assay showed that PPARγbinds to the putative PPAR-responsive elements (PPREs) within the 5′-flanking region of the humanLPP1gene. Genomic fragment containing 1.7-kilobase of the promoter region was cloned by using PCR. The luciferase reporter assays demonstrated that overexpression of PPARγand rosiglitazone, a specific ligand for PPARγ, could significantly upregulate the reporter activity. However, site-directed mutagenesis of the PPRE motif abolished the induction. In conclusion, our results demonstrated that PPARγtranscriptionally activated the expression ofLPP1gene in ECs, suggesting a potential role of PPARγin the metabolism of phospholipids.

CCL3 and CCL4, the Major Chemokines Produced by CD38+ Chronic Lymphocytic Leukemia Cells, Facilitate Microenvironmental Interactions of Neoplastic Cells Via the CD49d/VCAM Pair.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1055-1055
Author(s):  
Antonella Zucchetto ◽  
Dania Benedetti ◽  
Riccardo Bomben ◽  
Claudio Tripodo ◽  
Fleur Bossi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Peripheral Blood Cell ◽  
Lymphocytic Leukemia ◽  
Bone Marrow Biopsies ◽  
L Cells

Abstract CD38, a negative prognostic marker for patients with CLL, has been demonstrated to be a key molecule in the interactions occurring in the context of tumor microenvironment, mediating both survival and migratory signals for CLL cells. By taking advantage of gene expression profiling studies (GEP) comparing 11 CD38pos (CD38>30%) and 15 CD38neg (CD38<10%) CLLs, we identified as over-expressed in CD38pos CLL cells: i) genes for the two C-C chemokines CCL3 and CCL4 (median-log difference, MLD-CCL3= 3.5; MLD-CCL4=4.4); real-time quantitative PCR (RTQ-PCR) of selected cases confirmed GEP results; ii) the gene for CD49d (MLD=4.4); a high correlation between CD38 and CD49d protein expression, also characterizing the CLL series of the present study, has been reported previously. In vitro experiments, performed on purified tumor cells from additional 11 CD38pos CLL cases cultured for 14 (t14) and 24 (t24) hours in the presence of either the agonist anti-CD38 monoclonal antibody (mAb) IB4 or the non-agonistic anti-CD38 mAb IB6 as control, demonstrated upregulation of CCL3/CCL4 transcripts at t14 (CCL3: mean fold increase=18, p=0.041; CCL4: mean fold increase=13.8, p=0.005), as assessed by RTQ-PCR, and an increased release of CCL3/CCL4 proteins at t24 (CCL3: mean =0.9 ng/mL, mean fold increase=14, p=0.003; CCL4: mean =1.7 ng/mL, mean fold increase=49, p=0.01), as assessed by ELISA. Consistently, immunohistochemistry (IHC) analysis performed in bone marrow biopsies (BMB) from 20 CLL patients (10 CD38pos and 10 CD38neg cases) showed detectable levels of CCL3 in 8 cases, all but one belonging to the CD38pos group (p=0.02). Expression of the CCL3/CCL4 specific receptors CCR1 and CCR5 was examined by flow cytometry in peripheral blood cell subpopulations from 30 CLL (12 CD38pos and 18 CD38neg). Irrespectively of CD38 expression by CLL cells, monocytes showed the highest expression levels for CCR1 and, although at a lesser extent, CCR5. Consistently, CCL3 was able to attract CLL-derived monocytes by in-vitro chemotaxis experiments, and a higher number of infiltrating CD68pos macrophages were found in BMB of CD38pos compared to CD38neg CLLs (p=0.016). In parallel experiments, conditioned media (CM) from CCL3-stimulated macrophages were collected; these CM were able to induce expression of the CD49d-ligand VCAM in human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (ADMEC). As shown by ELISA, TNFalpha was among the cytokines contained in macrophage-CM. This citokine was likely responsible for VCAM up-regulation by HUVEC and ADMEC, as suggested by TNFalpha neutralization experiments leading to a suppression of VCAM-1 induction in endothelial cell models. Again, IHC analysis of CLL BMB showed a meshwork of VCAM-1-positive cells more prominent in the context of lymphoid infiltrates of CD38pos, as compared to CD38neg cases (p=0.002). To verify whether CD49d engagement through VCAM-1 could enhance the protection against spontaneous apoptosis of CLL cells in vitro, we cultured purified CD38pos/CD49dpos CLL cells from 5 cases onto VCAM-1-transfected L cells or mock-transfected L cells. Results demonstrated a substantial improvement in cell viability after CD49d engagement: as high as 70%±25 cells were viable after 10 days of culture on L-VCAM cells compared to 50%±25 in control conditions (p=0.009). Altogether, these results identify molecules involved in a functional cross-talk between CD38/CD49d-expressing CLL and cells of the tumor microenvironment. This interplay may eventually affect survival and recirculation of tumor cells via the CD49d/VCAM pair.

scholarly journals Tumor necrosis factor-mediated release of platelet-derived growth factor from cultured endothelial cells.

1987 ◽  
Vol 166 (1) ◽  
pp. 235-245 ◽  
Author(s):  
K A Hajjar ◽  
D P Hajjar ◽  
R L Silverstein ◽  
R L Nachman
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Mitogenic Activity ◽  
Platelet Derived Growth Factor ◽  
Adhesive Properties ◽  
Necrosis Factor

Platelet-derived growth factor (PDGF) is a 30,000-Mr glycoprotein that is chemotactic and mitogenic for vascular smooth muscle cells (SMC). It is also a potent vasoconstrictor. In the present study, we found that the macrophage-derived polypeptide, tumor necrosis factor (TNF), releases a factor from human umbilical vein endothelial cells (EC) that is mitogenic for SMC. Postculture medium from TNF-stimulated EC induced a 90% increase in mitogenesis is compared with controls. This effect was half-maximal at a TNF dose of 114 pM, reflected a 2.5-fold increase in PDGF-specific mRNA synthesis, and peaked at 15 h of TNF stimulation. Mitogenic activity was completely abrogated by preincubation of postculture medium with antibody to platelet PDGF. Stimulation of EC with IL-1 (60-240 pM) led to the release of similar mitogenic activity. Thus, in addition to its effects on the hemostatic and adhesive properties of EC, TNF also promotes release of PDGF, which may serve to modulate proliferation of vascular SMC during wound healing, inflammation, and atherogenesis.

scholarly journals ELEKTROFORESIS PROTEIN SERUM PASIEN DENGAN KADAR PROTEIN NORMAL

2018 ◽  
Vol 15 (3) ◽  
pp. 87
Author(s):  
Tiene Rostini ◽  
Coriejati Rita
Keyword(s):  
Serum Protein ◽  
Total Protein ◽  
Protein Level ◽  
Protein Electrophoresis ◽  
Serum Protein Electrophoresis ◽  
Total Protein Level ◽  
Normal Limits ◽  
Nephritic Syndrome ◽  
Serum Protein Level ◽  
Electrophoresis Pattern

Serum protein electrophoresis pattern can assist in diagnosis of liver disease, hematological disorders, renal disorders andgastrointestinal disease. Measurement of total protein level in the serum cannot detect any disorders in patient with normal limit ofserum total protein level. The aim of this study; was to evaluate the serum protein electrophoresis pattern in patient with normal limitsof serum protein level. This research was carried out by descriptive retrospective study using the electrophoresis data from patients’medical record at the Clinical Pathology Department, Dr. Hasan Sadikin General Hospital Bandung. The data of serum electrophoresis (bySebia gel electrophoresis) were grouped based on disease or disorders, and confirmed with the diagnosis derived from patient’s medicalrecord. Inclusion criteria of samples if ; the electrophoresis data were available, serum total protein level within normal limits (6.4–8.3mg/dL), and the data of electrophoresis taken from medical record were taken from August 2006 until August 2008. The result foundso far was, there were 240 data of electrophoresis from patients with serum protein level within normal limits (6.4–8.3 mg/dL). theinterpretation of electrophoresis consist of: 1) inflammation (149 patients; 62.2% ; sensitivity 83.7%, specificity 86,5%) 2) Cirrhosis(46 patients ; 19.2% ; sensitivity 87.5% ; specificity 88.4%) 3) Nephritic syndrome (15 patients ; 6.2%; sensitivity 53%; specificity96.9% 4) Monoclonal gammophaty (15 patients(6.2% ; sensitivity 80% ; specificity 98.7%) 5) Normal pattern in 15 patient (6.2%).This study found abnormal serum protein electrophoresis pattern in the condition of inflammation, Cirrhosis, Nephritic Syndrome, andMonoclonal gammophaty. It can be concluded that many disorders could be detected in patient with serum protein level within normallimits such as: inflammation, cirrhosis, nephritis syndrome and monoclonal gammophaty by abnormal electrophoresis pattern

Thrombin Induces Thromboplastin Synthesis in Cultured Vascular Endothelial Cells

1985 ◽  
Vol 54 (02) ◽  
pp. 373-376 ◽  
Author(s):  
K S Galdal ◽  
T Lyberg ◽  
S A Evensen ◽  
E Nilsen ◽  
H Prydz
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Calf Serum ◽  
Phosphodiesterase Inhibitors ◽  
Fold Increase ◽  
Homocysteine Thiolactone ◽  
Umbilical Vein Endothelial Cells

SummaryCultured human umbilical vein endothelial cells responded to thrombin (10−2 – 10 NIH u/ml) with a 2-5 fold increase in thromboplastin activity. The maximum response was reached after 4 hr in serum-free medium. The effect of thrombin was fully inhibited by the presence of 50% (v/v) fetal calf serum or more in the medium, by preincubation of thrombin with hirudin or by treatment of thrombin with N-bromosuccinimide or phenylmethylsulfonyl fluoride. The thrombin-induced thromboplastin activity was inhibited by incubation of the cells with cycloheximide (2 μg/ml) or actinomycin D (2 μg/ml) showing that the response depended on de novo protein and RNA synthesis. It was also suppressed by exposure of the cells to two different phosphodiesterase inhibitors, 3-butyl-l-methyl-xanthine (5 · 10−4 M) and rac-4 (3-butoxy-4-methoxybenzyl)-2-imidazole (5 · 10−4 M), to the transmethylation inhibitors 3-deazaadenosine (10−5 M) and 1-homocysteine thiolactone (2 · 10−5 M) in combination and to the intracellular calcium antagonist 8-(N,N-diethylamino)-octyl 3,4,5,-tri-methoxybenzoate hydrochloride (8 · 10−5 M). Our results suggest that small amounts of thrombin can induce thromboplastin synthesis in endothelial cells in vitro and that this synthesis probably is regulated by the intracellular level of cAMP, by cytoplasmic Ca2+ and possibly also by transmethylation reactions.

Sign in / Sign up

Export Citation Format

Share Document