Biochemical characterisation of polycation-induced cytotoxicity to human vascular endothelial cells

1989 ◽  
Vol 94 (3) ◽  
pp. 553-559 ◽  
Author(s):  
D.M. Morgan ◽  
V.L. Larvin ◽  
J.D. Pearson
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Endothelial ◽  
Cationic Proteins ◽  
Dose Time ◽  
Biochemical Characterisation ◽  
Human Granulocytes ◽  
Dependent Inhibition ◽  
Umbilical Vein Endothelial Cells

Pro-inflammatory effects of cationic proteins secreted by human granulocytes include induction of increased vascular permeability and oedema, which are likely to be mediated by damage to vascular endothelium. We have shown previously that a series of synthetic polycationic amino acids produce a dose-, time- and Mr-dependent inhibition of [3H]leucine or [3H]thymidine incorporation into macromolecules by human umbilical vein endothelial cells, and that the extent of inhibition was correlated with changes in cell morphology, with release of cytoplasmic constituents and was irreversible. The experiments reported here characterise further the requirements for the induction of cytotoxicity by polycations. We have found that the extent of inhibition is related to both the identity of the monomer, for polymers of Mr 40,000 the order is ornithine greater than lysine greater than arginine, and to its configuration; poly-D-lysines are more potent inhibitors than poly-L-lysines of similar Mr. Only brief exposure to the agonist is required, 90% inhibition occurred after 10 min of exposure to poly-L-lysine (Mr 90,000). Treatment of endothelial cells with neuraminidase, heparinase, hyaluronidase, chondroitinase or trypsin did not reduce their susceptibility to polylysine. Inhibition of microtubule or microfilament formation also had no effect on polylysine cytotoxicity, indicating that internalisation of the polymer was not a prerequisite for the effect. Inhibition of protein synthesis or pretreatment with simple sugars likewise failed to block the effects of polylysine treatment. Natural cationic proteins exerted similar effects on endothelial cells, the extent of the effect apparently being related to the pI of the protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of Arachidonic Acid Metabolism in Human Endothelial Cells by Glucocorticoids

1986 ◽  
Vol 55 (03) ◽  
pp. 369-374 ◽  
Author(s):  
Raffaele De Caterina ◽  
Babette B Weksler
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Arachidonic Acid Metabolism ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Prolonged Incubation ◽  
Dependent Inhibition ◽  
Human Thrombin ◽  
Umbilical Vein Endothelial Cells

SummaryTo learn whether glucocorticoids inhibit prostaglandin (PG) production in vascular endothelial cells, we investigated the effects of glucocorticoids on PG synthesis by cultured human umbilical vein endothelial cells (EC). Pretreatment of EC with dexamethasone (DX, 10-9 to 5 x 10-5 M) caused a dose-dependent inhibition of PGI2 production when PG synthesis from endogenous arachidonate was stimulated by human thrombin (0.25-2 U/ml) or ionophore A 23187 (1-5 μM). The inhibition was detectable at 10-7 M DX and maximal at 10-5 M (4.0 ± 0.7 vs. control: 7.7 ± 1.9 ng/ml, mean ± S.D., P <0.01). The production of PGE2 and the release of radiolabelled arachidonate (AA) from prelabelled cells were similarly inhibited. Prolonged incubation of EC with glucocorticoids was required to inhibit PG production or arachidonate release: ranging from 8% inhibition at 5 h to 44% at 38 h. In contrast, prostaglandin formation from exogenous AA was not altered by DX treatment. When thrombin or ionophore-stimulated EC were restimulated with exogenous AA (25 μM), DX-treated cells released more PGI2 than control cells (5.7 ± 0.5 vs. 4.1 ± 0.6 ng/ml, P <0.01). Both the decrease in PGI2 production after thrombin/ionophore and the increase after re-stimulation with AA were blunted in the presence of the protein synthesis inhibitor cycloheximide (0.1-0.2 μg/ml). Thus, incubation of EC with glucocorticoids inhibits PG production at the step of phospholipase activation. The time requirement for these steroid effects and their blunting by cycloheximide are consistent with the induction of regulatory proteins, possibly lipocortins, in endothelial cells.

scholarly journals Citrus bergamiaRisso Elevates Intracellular Ca2+in Human Vascular Endothelial Cells due to Release of Ca2+from Primary Intracellular Stores

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Purum Kang ◽  
Seung Ho Han ◽  
Hea Kyung Moon ◽  
Jeong-Min Lee ◽  
Hyo-Keun Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Channel Blocker ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Concentration Dependent Manner ◽  
Carbonyl Cyanide ◽  
Intracellular Ca ◽  
Umbilical Vein Endothelial Cells

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.

scholarly journals CRIF1 Deficiency Increased Homocysteine Production by Disrupting Dihydrofolate Reductase Expression in Vascular Endothelial Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1645
Author(s):  
Ikjun Lee ◽  
Shuyu Piao ◽  
Seonhee Kim ◽  
Harsha Nagar ◽  
Su-Jeong Choi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Dihydrofolate Reductase ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Plasma Concentrations ◽  
Vascular Endothelial ◽  
Cell Dysfunction ◽  
Key Enzyme ◽  
Umbilical Vein Endothelial Cells ◽  
Folate Cycle

Elevated plasma homocysteine levels can induce vascular endothelial dysfunction; however, the mechanisms regulating homocysteine metabolism in impaired endothelial cells are currently unclear. In this study, we deleted the essential mitoribosomal gene CR6 interacting factor 1 (CRIF1) in human umbilical vein endothelial cells (HUVECs) and mice to induce endothelial cell dysfunction; then, we monitored homocysteine accumulation. We found that CRIF1 downregulation caused significant increases in intracellular and plasma concentrations of homocysteine, which were associated with decreased levels of folate cycle intermediates such as 5-methyltetrahydrofolate (MTHF) and tetrahydrofolate (THF). Moreover, dihydrofolate reductase (DHFR), a key enzyme in folate-mediated metabolism, exhibited impaired activity and decreased protein expression in CRIF1 knockdown endothelial cells. Supplementation with folic acid did not restore DHFR expression levels or MTHF and homocysteine concentrations in endothelial cells with a CRIF1 deletion or DHFR knockdown. However, the overexpression of DHFR in CRIF1 knockdown endothelial cells resulted in decreased accumulation of homocysteine. Taken together, our findings suggest that CRIF1-deleted endothelial cells accumulated more homocysteine, compared with control cells; this was primarily mediated by the disruption of DHFR expression.

scholarly journals GPR55 Antagonist CID16020046 Protects against Atherosclerosis Development in Mice by Inhibiting Monocyte Adhesion and Mac-1 Expression

2021 ◽  
Vol 22 (23) ◽  
pp. 13084
Author(s):  
Seung-Jin Lee ◽  
Dong-Soon Im
Keyword(s):  
Endothelial Cells ◽  
High Fat Diet ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Endothelial ◽  
Monocyte Adhesion ◽  
High Fat ◽  
Potent Agonist ◽  
Atherosclerosis Development ◽  
Umbilical Vein Endothelial Cells

GPR55 recognizes several lipid molecules such as lysophosphatidylinositol. GPR55 expression was reported in human monocytes. However, its role in monocyte adhesion and atherosclerosis development has not been studied. The role of GPR55 in monocyte adhesion and atherosclerosis development was investigated in human THP-1 monocytes and ApoE−/− mice using O-1602 (a potent agonist of GPR55) and CID16020046 (a specific GPR55 antagonist). O-1602 treatment significantly increased monocyte adhesion to human umbilical vein endothelial cells, and the O-1602-induced adhesion was inhibited by treatment with CID16020046. O-1602 induced the expression of Mac-1 adhesion molecules, whereas CID16020046 inhibited this induction. Analysis of the promoter region of Mac-1 elucidated the binding sites of AP-1 and NF-κB between nucleotides −750 and −503 as GPR55 responsive elements. O-1602 induction of Mac-1 was found to be dependent on the signaling components of GPR55, that is, Gq protein, Ca2+, CaMKK, and PI3K. In Apo−/− mice, administration of CID16020046 ameliorated high-fat diet-induced atherosclerosis development. These results suggest that high-fat diet-induced GPR55 activation leads to the adhesion of monocytes to endothelial cells via induction of Mac-1, and CID16020046 blockage of GPR55 could suppress monocyte adhesion to vascular endothelial cells through suppression of Mac-1 expression, leading to protection against the development of atherosclerosis.

scholarly journals TKI-Resistant Renal Cancer Secretes Low-Level Exosomal miR-549a to Induce Vascular Permeability and Angiogenesis to Promote Tumor Metastasis

2021 ◽  
Vol 9 ◽  
Author(s):  
Zuodong Xuan ◽  
Chen Chen ◽  
Wenbin Tang ◽  
Shaopei Ye ◽  
Jianzhong Zheng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Permeability ◽  
Renal Cancer ◽  
Kinase Inhibitors ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Endothelial Permeability ◽  
Vascular Endothelial ◽  
Cell Renal Cell Carcinoma ◽  
Umbilical Vein Endothelial Cells

Tyrosine kinase inhibitors (TKI)-resistant renal cancer is highly susceptible to metastasis, and enhanced vascular permeability promotes the process of metastasis. To evaluate the effect of cancer-derived exosomes on vascular endothelial cells and clarify the mechanism of metastasis in TKI-resistant renal cancer, we studied the crosstalk between clear cell renal cell carcinoma (ccRCC) cells and human umbilical vein endothelial cells (HUVECs). Exosomes from ccRCC cells enhanced the expression of vascular permeability-related proteins. Compared with sensitive strains, exosomes from resistant strains significantly enhanced vascular endothelial permeability, induced tumor angiogenesis and enhanced tumor lung metastasis in nude mice. The expression of miR-549a is lower in TKI-resistant cells and exosomes, which enhanced the expression of HIF1α in endothelial cells. In addition, TKI-resistant RCC cells reduced nuclear output of pre-miR-549a via the VEGFR2-ERK-XPO5 pathway, and reduced enrichment of mature miR-549a in cytoplasm, which in turn promoted HIF1α expression in RCC, leading to increased VEGF secretion and further activated VEGFR2 to form a feedback effect. miR-549a played an important role in the metastasis of renal cancer and might serve as a blood biomarker for ccRCC metastasis and even had the potential of becoming a new drug to inhibit TKI-resistance.

scholarly journals Dexmedetomidine Attenuates Monocyte-Endothelial Adherence via Inhibiting Connexin43 on Vascular Endothelial Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yunfei Chai ◽  
Runying Yu ◽  
Yong Liu ◽  
Sheng Wang ◽  
Dongdong Yuan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Underlying Mechanism ◽  
Mapk Signaling ◽  
Vascular Endothelial ◽  
Cx43 Expression ◽  
Multiple Organs ◽  
Key Factor ◽  
Umbilical Vein Endothelial Cells

Current studies have identified the multifaceted protective functions of dexmedetomidine on multiple organs. For the first time, we clarify effects of dexmedetomidine on monocyte-endothelial adherence and whether its underlying mechanism is relative to connexin43 (Cx43), a key factor regulating monocyte-endothelial adherence. U937 monocytes and human umbilical vein endothelial cells (HUVECs) were used to explore monocyte-endothelial adherence. Two special siRNAs were designed to knock down Cx43 expression on HUVECs. U937-HUVEC adhesion, adhesion-related molecules, and the activation of the MAPK (p-ERK1/2, p-p38, and p-JNK1/2) signaling pathway were detected. Dexmedetomidine, at its clinically relevant concentrations (0.1 nM and 1 nM), was given as pretreatments to HUVECs. Its effects on Cx43 and U937-HUVEC adhesion were also investigated. The results show that inhibiting Cx43 on HUVECs could attenuate the contents of MCP-1, soluble ICAM-1 (sICAM-1), soluble VCAM-1 (sVCAM-1), and the nonprocessed variants of the adhesion molecules ICAM-1 and VCAM-1 and ultimately result in U937-HUVEC adhesion decrease. Meanwhile, the activation of MAPKs was also inhibited. U0126 (inhibiting p-ERK1/2) and SB202190 (inhibiting p38) decreased the contents of MCP-1, sICAM-1, and sVCAM-1, but SP600125 (inhibiting p-JNK1/2) had none of these effects. ICAM-1 and VCAM-1 could be regulated in a similar way. Dexmedetomidine pretreatment inhibited Cx43 on HUVECs, the activation of MAPKs, and U937-HUVEC adhesion. Therefore, we conclude that dexmedetomidine attenuates U937-HUVEC adhesion via inhibiting Cx43 on HUVECs modulating the activation of MAPK signaling pathways.

scholarly journals miR-101-3p induces vascular endothelial cell dysfunction by targeting tet methylcytosine dioxygenase 2

2020 ◽  
Vol 52 (2) ◽  
pp. 180-191 ◽  
Author(s):  
Qiaoli Chen ◽  
Xiaoye Li ◽  
Lingjun Kong ◽  
Qing Xu ◽  
Zi Wang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Nuclear Factor Κb ◽  
Vascular Endothelial ◽  
Ros Production ◽  
Cell Dysfunction ◽  
Umbilical Vein Endothelial Cells

Abstract Endothelial cell (EC) dysfunction represents an early key event in atherosclerosis. Recently, MicroRNAs have been demonstrated to regulate EC function. miR-101-3p has been discovered to regulate cell apoptosis and proliferation in cardiovascular diseases. Therefore, the aim of the current study was to clarify whether miR-101-3p regulates the dysfunction of vascular endothelial cells. In this study, the transfection of human umbilical vein endothelial cells (HUVECs) with miR-101-3p mimic induced reactive oxygen species (ROS) production, EC dysfunction, and activated nuclear factor-κB (NF-κB), whereas transfection with miR-101-3p inhibitor alleviated these events. The antioxidant N-acetylcysteine alleviated miR-101-3p-induced EC dysfunction. Moreover, we observed that miR-101-3p inhibited the expression of tet methylcytosine dioxygenase 2 (TET2) at the posttranscriptional level, resulting in increased ROS production and activated NF-κB. TET2 overexpression inhibited ROS production, EC dysfunction, and NF-κB activation in miR-101-3p-transfected HUVECs. These results indicate that miR-101-3p induces EC dysfunction by targeting TET2, which regulates ROS production, EC dysfunction, and NF-κB activation. Taken together, our current study reveals a novel pathway associated with EC dysfunction. The modulation of miR-101-3p and TET2 expression levels may serve as a potential target for therapeutic strategies for atherosclerosis.

scholarly journals RASGRP2 Suppresses Apoptosis via Inhibition of ROS Production in Vascular Endothelial Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Takuma Sato ◽  
Jun-ichi Takino ◽  
Kentaro Nagamine ◽  
Kazuto Nishio ◽  
Takamitsu Hori
Keyword(s):  
Endothelial Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Endothelial ◽  
Ros Production ◽  
Overexpressing Cell ◽  
The Difference ◽  
Umbilical Vein Endothelial Cells

We have identified ras guanyl releasing protein 2 (rasgrp2) as a blood vessel related gene from Xenopus embryo. In addition, we reported that RASGRP2 is also expressed in human umbilical vein endothelial cells (HUVEC). It is known that RASGRP2 activates Ras-related protein 1 (Rap1). However, the function of RASGRP2 in human vascular endothelium remains unknown. Therefore, we performed functional analysis of RASGRP2 using immortalized HUVEC (TERT HUVEC). We established a stable RASGRP2 overexpressing cell line (TERT HUVEC R) and mock cell line (mock). Furthermore, we compared the activity of Rap1 and the generation of intracellular reactive oxygen species (ROS), which is related to cell death, in both cell lines. Significant increase in Rap1 activity was observed in the TERT HUVEC R compared to the mock. Furthermore, apoptosis by tumor necrosis factor-α (TNF-α) stimulation was significantly more reduced in the TERT HUVEC R than in the mock. In the mock, apoptosis induced by TNF-α stimulation was decreased by pretreatment with diphenyleneiodonium (DPI), which is an inhibitor of NADPH oxidase (NOX). However, in the TERT HUVEC R, apoptosis induced by TNF-α stimulation was not reduced after pretreatment of DPI. Furthermore, there was no reduction in ROS production in the TERT HUVEC R after DPI pretreatment. In addition, the difference in the degree of apoptosis induced by TNF-α stimulation in both cell lines was consistent with the difference in ROS production in the cell lines. From these results, it was suggested that RASGRP2 activates Rap1 and the activated Rap1 suppresses apoptosis via NOX inhibition.

Two distinct HCO 3 − -dependent H+ efflux pathways in human vascular endothelial cells

1999 ◽  
Vol 277 (1) ◽  
pp. H28-H32 ◽  
Author(s):  
Bing Sun ◽  
Richard D. Vaughan-Jones ◽  
Jun-Ichi Kambayashi
Keyword(s):  
Endothelial Cells ◽  
Intracellular Ph ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Complete Recovery ◽  
The Other ◽  
Vascular Endothelial ◽  
Free Solution ◽  
Acid Load ◽  
Umbilical Vein Endothelial Cells

Intracellular pH (pHi) regulation in human umbilical vein endothelial cells (HUVEC) was investigated. The pHi was recorded using seminaphthorhodafluor-1 (SNARF-1). Cells were intracellularly acid loaded with NH4Cl prepulse. In HEPES-buffered Tyrode (nominally [Formula: see text]free), pHi recovery from acid load was inhibited by 1.5 mM amiloride or Na+-free solution. Additionally, in [Formula: see text]-buffered Tyrode, a[Formula: see text]-dependent pHi recovery from acidosis was evident in the presence of 1.5 mM amiloride, which mediated complete recovery of pHi (7.26). In Na+-free solution, the[Formula: see text]-dependent acid extruder mediated pHi recovery after an acid load but only back to 7.09. These results suggest that there are two[Formula: see text]-dependent acid extruders in the HUVEC. One is Na+ dependent, and the other is Na+ independent. The former was further shown to be completely inhibited by 0.5 mM DIDS, whereas the latter was only inhibited by 24.6%. In Cl−-free solution, both of the [Formula: see text]-dependent pathways were inhibited. In conclusion, one[Formula: see text]-dependent acid extruder in the HUVEC resembles the Na+-dependent Cl−/[Formula: see text]exchange found in other tissues, and the other is Cl− dependent but Na+ independent.

scholarly journals Apoptotic Vascular Endothelial Cells Become Procoagulant

Blood ◽  
1997 ◽  
Vol 89 (7) ◽  
pp. 2429-2442 ◽  
Author(s):  
Thomas Bombeli ◽  
Aly Karsan ◽  
Jonathan F. Tait ◽  
John M. Harlan
Keyword(s):  
Endothelial Cells ◽  
Kinase Inhibitor ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Annexin V ◽  
Vascular Endothelial ◽  
Flow Cytometric ◽  
Heparan Sulfates ◽  
Umbilical Vein Endothelial Cells ◽  
Membrane Components

Abstract Whereas unperturbed endothelial cells provide potent anticoagulant properties, exposure to inflammatory and atherogenic stimuli can rapidly lead to a procoagulant behavior. Because recent studies provide evidence that apoptosis of vascular cells may occur under conditions such as atherosclerosis and inflammation, we investigated whether apoptotic endothelial cells may contribute to the development of a prothrombotic state. In this report, it is shown that both adherent and detached apoptotic human umbilical vein endothelial cells (HUVECs) become procoagulant. Apoptosis was induced by staurosporine, a nonspecific protein kinase inhibitor, or by culture in suspension with serum deprivation. Both methods resulted in similar findings. As assessed by flow cytometric determination of annexin V binding, HUVECs undergoing cell death exhibited typically a more rapid exposure of membrane phosphatidylserine (PS) than DNA fragmentation. Depending on the stage of apoptosis, this redistribution of phospholipids was found to induce an increase of the activity of the intrinsic tenase complex by 25% to 60%. Although apoptotic cells did not show antigenic or functional tissue factor (TF ) activity, when preactivated with lipopolysaccharide, TF procoagulant activity increased by 50% to 70%. At 8 hours after apoptosis induction, antigenic thrombomodulin, heparan sulfates, and TF pathway inhibitor decreased by about 83%, 80%, and 59%, respectively. The functional activity of these components was reduced by about 36%, 52%, and 39%, respectively. Moreover, the presence of apoptotic HUVECs led to a significant increase of thrombin formation in recalcified citrated plasma. In conclusion, apoptotic HUVECs, either adherent or in suspension, become procoagulant by increased expression of PS and the loss of anticoagulant membrane components.

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