scholarly journals Differential regulation of glutathione peroxidase by selenomethionine and hyperoxia in endothelial cells

1995 ◽  
Vol 306 (2) ◽  
pp. 581-587 ◽  
Author(s):  
L Jornot ◽  
A F Junod
Keyword(s):  
Endothelial Cells ◽  
Glutathione Peroxidase ◽  
Gene Transcription ◽  
Umbilical Vein ◽  
Specific Inhibitor ◽  
Mrna Levels ◽  
Normal Medium ◽  
Initiation Step ◽  
Umbilical Vein Endothelial Cells ◽  
In Cells

We have studied the effect of selenomethionine (SeMet) and hyperoxia on the expression of glutathione peroxidase (GP) in human umbilical vein endothelial cells. Incubation of HUVEC with 1 x 10(-6) M SeMet for 24 h and 48 h caused a 65% and 86% increase in GP activity respectively. The same treatment did not result in significant changes in GP gene transcription and mRNA levels. Pactamycin, a specific inhibitor of the initiation step of translation, prevented the rise in GP activity induced by SeMet and caused an increase in GP mRNA in both cells grown in normal and SeMet-supplemented medium. Interestingly, SeMet supplementation stimulated the recruitment of GP mRNA from an untranslatable pool on to polyribosomes, so that the concentration of GP mRNA in polyribosomal translatable pools was 50% higher in cells grown in SeMet-supplemented medium than in cells grown in normal medium. On the other hand, cells exposed to 95% O2 for 3 days in normal medium showed a 60%, 394% and 81% increase in GP gene transcription rate, mRNA levels and activity respectively. Hyperoxia also stabilized GP mRNA. Hyperoxic cells grown in SeMet-supplemented medium did not show any change in GP gene transcription and mRNA levels, but expressed an 81% and 100% increase in GP activity and amount of GP mRNA associated with polyribosomes respectively, when compared with hyperoxic cells maintained in normal medium. Thus, GP appeared to be regulated post-transcriptionally, most probably co-translationally, in response to selenium availability, and transcriptionally and post-transcriptionally in response to oxygen.

Sp1-mediated downregulation of P2X4 receptor gene transcription in endothelial cells exposed to shear stress

2001 ◽  
Vol 280 (5) ◽  
pp. H2214-H2221 ◽  
Author(s):  
Risa Korenaga ◽  
Kimiko Yamamoto ◽  
Norihiko Ohura ◽  
Takaaki Sokabe ◽  
Akira Kamiya ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Gene Transcription ◽  
Fluid Shear Stress ◽  
Adenine Nucleotides ◽  
Umbilical Vein ◽  
Receptor Gene ◽  
Mrna Levels ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Endothelial purinoceptors play an important role in vascular responses to extracellular adenine nucleotides and hemodynamic forces. Here we report that P2X4 purinoceptor expression in human umbilical vein endothelial cells is transcriptionally downregulated by fluid shear stress. When human umbilical vein endothelial cells were subjected to a laminar shear stress of 15 dyn/cm2, P2X4 mRNA levels began to decrease within 1 h and further decreased with time, reaching 60% at 24 h. Functional analysis of the 1.9-kb P2X4 5′-promoter indicated that a 131-bp segment (−112 to +19 bp relative to the transcription start site) containing a consensus binding site for the Sp1 transcription factor was critical for the shear stress responsiveness. Mutations of the Sp1 site decreased the basal level of transcription and abolished the response of the P2X4 promoter to shear stress. Electrophoretic mobility shift assays showed a marked decrease in binding of Sp1 to the Sp1 consensus element in shear-stressed cells, suggesting that Sp1 mediates the shear stress-induced downregulation of P2X4 gene transcription.

Hypoxia-induced pulmonary endothelin-1 expression is unaltered by nitric oxide

2002 ◽  
Vol 92 (3) ◽  
pp. 1152-1158 ◽  
Author(s):  
Scott Earley ◽  
Leif D. Nelin ◽  
Louis G. Chicoine ◽  
Benjimen R. Walker
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Promoter Activity ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Exposure ◽  
Mrna Levels ◽  
Protective Effects ◽  
No Donor ◽  
Umbilical Vein Endothelial Cells

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O2) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso- N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O2) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O2) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O2) exposure. ET-1 promoter activity after S-nitroso- N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.

Lysophosphatidylcholine Decreases the Synthesis of Tissue Factor Pathway Inhibitor in Human Umbilical Vein Endothelial Cells

1998 ◽  
Vol 79 (01) ◽  
pp. 217-221 ◽  
Author(s):  
Koichi Kokame ◽  
Toshiyuki Miyata ◽  
Naoaki Sato ◽  
Hisao Kato
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Umbilical Vein ◽  
Mrna Levels ◽  
Down Regulation ◽  
Human Umbilical Vein ◽  
Tissue Factor Pathway ◽  
Umbilical Vein Endothelial Cells

SummaryThrombotic complications are frequently associated with atherosclerosis. Lysophosphatidylcholine (LPC), a component accumulated in oxidatively modified LDL (ox-LDL), is known to play a crucial role in the initiation and progression of atherosclerotic vascular lesions. Since a vascular anticoagulant, tissue factor pathway inhibitor (TFPI), has the function of regulating the initial reaction of tissue factor (TF)-induced coagulation, we investigated the effect of LPC on TFPI synthesis in cultured human umbilical vein endothelial cells (HUVEC). The treatment of HUVEC with LPC for 24 h decreased TFPI antigen levels in both the culture medium and the cell lysate in a dose-dependent manner. Northern blot analysis revealed that LPC caused a time-dependent decrease in the TFPI mRNA levels. The levels of TFPI antigen and mRNA were decreased to 72% and 38%, respectively, by the incubation with 50 μM LPC for 24 h. The down-regulation by LPC of TFPI mRNA expression was not observed in the presence of cycloheximide, suggesting that protein synthesis was involved in the suppression of TFPI mRNA expression. The TFPI mRNA levels in actinomycin D-treated cells were relatively stable, indicating that the down-regulation of TFPI mRNA by LPC would be partly explained by the enhanced mRNA destabilization. In contrast to the significant down-regulatory effects of LPC on TFPI expression, LPC did not induce TF mRNA expression in HUVEC. These results indicate that LPC accumulated in the atherosclerotic vascular wall would suppress endothelial TFPI synthesis, reducing the antithrombotic property of endothelial cells.

scholarly journals Up-regulation of thrombomodulin by activation of histamine H1-receptors in human umbilical-vein endothelial cells in vitro

1991 ◽  
Vol 276 (3) ◽  
pp. 739-743 ◽  
Author(s):  
K Hirokawa ◽  
N Aoki
Keyword(s):  
Endothelial Cells ◽  
Phorbol Esters ◽  
Umbilical Vein ◽  
Feedback Regulation ◽  
Mrna Levels ◽  
Human Umbilical Vein ◽  
H2 Antagonist ◽  
Histamine H1 Receptors ◽  
Umbilical Vein Endothelial Cells

Previous reports demonstrated that the expression of thrombomodulin (TM) in endothelial cells was modulated by various agents. Although TM was down-regulated by endotoxin or cytokines, up-regulation of TM was accomplished when endothelial cells were stimulated with unphysiologically high concentrations of cyclic AMP derivatives or tumour-promoting phorbol esters. We investigated the expression of TM in human umbilical-vein endothelial cells (HUVECs) by physiological substances that can be released into the bloodstream. Histamine (0.1-10 microM, 1-48 h) increased TM activity, TM antigen in cell lysates and TM mRNA levels, but 5-hydroxytryptamine and bradykinin had no effect. Enhancement of TM activity by histamine was completely blocked by the H1-selective antagonist pyrilamine, whereas the H2-antagonist cimetidine had no effect, showing that histamine up-regulates TM activity via H1-receptors on HUVECs. Enhanced TM activity by histamine and the resultant increase in protein C activation might play a role in a feedback regulation for prevention of vascular thrombosis.

Transforming Growth Factor Betal and Beta2 Induce Down-Modulation of Thrombomodulin in Human Umbilical Vein Endothelial Cells

1995 ◽  
Vol 73 (05) ◽  
pp. 812-818 ◽  
Author(s):  
Taro Ohji ◽  
Hajime Urano ◽  
Akira Shirahata ◽  
Minoru Yamagishi ◽  
Ken Higashi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Time Course ◽  
Transforming Growth Factor ◽  
Umbilical Vein ◽  
Mrna Levels ◽  
Antigen Level ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells ◽  
Tgf Β1

SummaryTo investigate the effects of transforming growth factor-betas (TGF-βs) on endothelial anticoagulant activity, we assayed thrombomodulin (TM) activity and antigen levels of human umbilical vein endothelial cells (HUVECs) incubated with TGF-βs in vitro. TGF-β1 suppressed surface TM activity and surface TM antigen levels maximally 12 h after incubation in dose-dependent manners. TGF-β2 was almost equipotent with TGF-β1 for the suppression of them. Both TGF-βs suppressed total TM antigen level in HUVECs, and the time course of the suppression was similar to that of the cell surface TM antigen level. The maximal reductions of TM mRNA levels by TGF-βs were observed at several hours ahead of those observed in both surface and total TM antigen levels, suggesting that the TGF-β-mediated suppression of TM antigen of HUVECs is primarily regulated at the TM mRNA level. Our present work suggests that the down-modulation of TM level induced by TGF-βs in HUVECs contributes in vivo to promoting the thrombogenesis either at the sites of injury of vessel walls, such as atherosclerotic lesions where TGF-β1 is released from platelets, smooth muscle cells and monocytes, or at neovascular walls in tumors secreting TGF-β2.

Contribution of ecto-5′-nucleotidase to the inhibition of platelet aggregation by human endothelial cells

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2157-2162 ◽  
Author(s):  
Yasuko Kawashima ◽  
Toshiro Nagasawa ◽  
Haruhiko Ninomiya
Keyword(s):  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Adenine Nucleotides ◽  
Umbilical Vein ◽  
Specific Inhibitor ◽  
Adenosine Diphosphate ◽  
Inhibition Of Platelet Aggregation ◽  
A2a Receptor ◽  
Agonistic Activity ◽  
Umbilical Vein Endothelial Cells

We studied the role of adenosine (Ado), which is generated from adenine nucleotides via the activity of ecto-5′-nucleotidase (ecto-5′-NT), in the inhibition of platelet aggregation by endothelial cells (ECs). The enzymatic activity of nucleotidases on human umbilical vein endothelial cells (HUVECs) was examined with regard to (1) the inhibition of adenosine diphosphate (ADP)–induced platelet aggregation and (2) the liberation of inorganic phosphate from adenine nucleotides. Adenosine 5′-monophosphate (AMP) preincubated with HUVECs significantly inhibited ADP-induced platelet aggregation. This was completely blocked by the treatment of HUVECs with a specific inhibitor of ecto-5′-NT, 5′-[αβ-methylene] diphosphate (APCP), or by the addition of an A2a receptor antagonist. Neither nitric oxide nor prostacyclin was involved in this inhibitory activity, suggesting that Ado generated in the incubation medium by the activity of 5′-NT on HUVECs inhibited platelet aggregation. When ADP was incubated on HUVECs, it lost most of its agonistic activity for platelets. Pretreatment of HUVECs with APCP at a concentration that abolished ecto-5′-NT activity partially restored ADP-induced platelet aggregation. Ecto-5′-NT contributes to EC function by inhibiting platelet aggregation in cooperation with ATP diphosphohydrolase, which degrades ADP to AMP.

scholarly journals YB-1 transferred by gastric cancer exosomes promotes angiogenesis via enhancing the expression of angiogenic factors in vascular endothelial cells

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaoxia Xue ◽  
Jin Huang ◽  
Kai Yu ◽  
Xinyue Chen ◽  
Yini He ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Angiogenic Factors ◽  
Mrna Levels ◽  
Protein Levels ◽  
Significant Difference ◽  
Umbilical Vein Endothelial Cells ◽  
Intercellular Communications

Abstract Background Angiogenesis is important for the progression of gastric cancer (GC). Y-box binding protein 1 (YB-1) predicts advanced disease and indicates neovasculature formation in GC tissues, while the related mechanisms remain elusive. Exosomes mediate intercellular communications via transferring various molecules including proteins, lipids, mRNAs, and microRNAs, while the cargos of GC exosomes and the related mechanisms in GC angiogenesis were rarely reported except for several microRNAs. Methods In this study, human umbilical vein endothelial cells (HUVECs) were, respectively, treated by the exosomes isolated from the YB-1 transfected and the control SGC-7901 cells (SGC-7901-OE-Exo and SGC-7901-NC-Exo), and their apoptosis, proliferation, migration, invasion, and angiogenesis were, sequentially, compared. The levels of angiogenic factors including VEGF, Ang-1, MMP-9 and IL-8 in the exosome-treated HUVECs and the GC-derived exosomes were, separately, detected using PCR and Western blotting as well as RNA sequencing assays. Results We observed the consistent level of YB-1 in the exosomes and their originated GC cells, and the internalization of exosomes into HUVECs. Comparing with SGC-7901-NC-Exo, SGC-7901-OE-Exo significantly inhibited the apoptosis but promoted the proliferation, migration, invasion, and angiogenesis of HUVECs, within which the increased mRNA and protein levels of VEGF, Ang-1, MMP-9 and IL-8 were demonstrated. Meanwhile, mRNA levels of VEGF, Ang-1, MMP-9 and IL-8 showed no significant difference between SGC-7901-NC-Exo and SGC-7901-OE-Exo, although statistically higher mRNA of YB-1 was detected in the SGC-7901-OE-Exo. Conclusions Our findings illustrate YB-1 as the key component of exosome to promote GC angiogenesis by upregulating specific angiogenic factors in the exosome-treated endothelial cells but not in the exosomes themselves.

Human endothelial cell response to gram-negative lipopolysaccharide assessed with cDNA microarrays

2001 ◽  
Vol 281 (5) ◽  
pp. C1587-C1595 ◽  
Author(s):  
Baiteng Zhao ◽  
Robert A. Bowden ◽  
Salomon A. Stavchansky ◽  
Phillip D. Bowman
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Cdna Microarrays ◽  
Nuclear Factor Κb ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Chemotactic Protein ◽  
Endothelial Cell Response ◽  
Umbilical Vein Endothelial Cells ◽  
Microarray Studies

To assess the feasibility of using cDNA microarrays to understand the response of endothelial cells to lipopolysaccharide (LPS) and to evaluate potentially beneficial agents in treatment of septic shock, human umbilical vein endothelial cells were exposed to Escherichia coli LPS for 1, 4, 7, 12, or 24 h. Total RNA was isolated and reverse-transcribed into33P-labeled cDNA probes that were hybridized to human GeneFilter microarrays containing ∼4,000 genes. The mRNA levels of several genes known to respond to LPS changed after stimulation. In addition, a number of genes not previously implicated in the response of endothelial cells to LPS also appeared to be altered in expression. Nuclear factor-κB (NF-κB) was shown to play an important role in regulating genes identified from the microarray studies. Pretreatment of endothelial cells with a specific NF-κB translocation inhibitor eliminated most of the alterations in gene expression. Quantitative RT-PCR results independently confirmed the microarray results for monocyte chemotactic protein-1 and interleukin-8, and enzyme-linked immunosorbent assays demonstrated that augmented transcription was followed by translation and secretion.

Contribution of ecto-5′-nucleotidase to the inhibition of platelet aggregation by human endothelial cells

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2157-2162 ◽  
Author(s):  
Yasuko Kawashima ◽  
Toshiro Nagasawa ◽  
Haruhiko Ninomiya
Keyword(s):  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Adenine Nucleotides ◽  
Umbilical Vein ◽  
Specific Inhibitor ◽  
Adenosine Diphosphate ◽  
Inhibition Of Platelet Aggregation ◽  
A2a Receptor ◽  
Agonistic Activity ◽  
Umbilical Vein Endothelial Cells

Abstract We studied the role of adenosine (Ado), which is generated from adenine nucleotides via the activity of ecto-5′-nucleotidase (ecto-5′-NT), in the inhibition of platelet aggregation by endothelial cells (ECs). The enzymatic activity of nucleotidases on human umbilical vein endothelial cells (HUVECs) was examined with regard to (1) the inhibition of adenosine diphosphate (ADP)–induced platelet aggregation and (2) the liberation of inorganic phosphate from adenine nucleotides. Adenosine 5′-monophosphate (AMP) preincubated with HUVECs significantly inhibited ADP-induced platelet aggregation. This was completely blocked by the treatment of HUVECs with a specific inhibitor of ecto-5′-NT, 5′-[αβ-methylene] diphosphate (APCP), or by the addition of an A2a receptor antagonist. Neither nitric oxide nor prostacyclin was involved in this inhibitory activity, suggesting that Ado generated in the incubation medium by the activity of 5′-NT on HUVECs inhibited platelet aggregation. When ADP was incubated on HUVECs, it lost most of its agonistic activity for platelets. Pretreatment of HUVECs with APCP at a concentration that abolished ecto-5′-NT activity partially restored ADP-induced platelet aggregation. Ecto-5′-NT contributes to EC function by inhibiting platelet aggregation in cooperation with ATP diphosphohydrolase, which degrades ADP to AMP.

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