scholarly journals In vitro ability of Staphylococcus aureus isolates from bacteraemic patients with and without metastatic complications to invade vascular endothelial cells

2007 ◽  
Vol 56 (10) ◽  
pp. 1290-1295 ◽  
Author(s):  
Wan Beom Park ◽  
Sung Han Kim ◽  
Cheol-in Kang ◽  
Jae Hyun Cho ◽  
Ji Whan Bang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Control Group ◽  
Vascular Endothelial ◽  
Tertiary Referral Hospital ◽  
Metastatic Infection ◽  
Umbilical Vein Endothelial Cells

Invasion of vascular endothelial cells is thought to be a critical step in the development of metastatic infections in patients with Staphylococcus aureus bacteraemia. This study was designed to evaluate the association between the ability to invade endothelial cells and metastatic infection by S. aureus. Patients with metastatic infection were identified among those with community-acquired S. aureus bacteraemia in a tertiary referral hospital. Patients with simple bacteraemia caused by S. aureus over the same period served as the control group. The ability of each clinical isolate to invade endothelial cells was evaluated by counting the number of intracellular organisms 1 h after inoculation onto human umbilical vein endothelial cells in vitro. The cytotoxic activity of intracellular S. aureus was determined 24 h after internalization, and expressed as the percentage of cells killed. The clinical isolates varied in invasiveness and cytotoxicity. The median invasiveness, relative to S. aureus reference strain ATCC 29213, was 145  % in the cases (n=10) [interquartile range (IQR) 103–160] and 153  % (IQR 111–173) in the controls (n=11; P=0.44). The median cytotoxicity was 59.4  % (IQR 47–68) in the cases and 65.2  % (IQR 50–74) in the controls (P=0.44). Differences in the ability of S. aureus to invade and destroy vascular endothelial cells in vitro were not associated with the development of metastatic complications in patients with S. aureus bacteraemia. This implies that the invasiveness and toxicity of S. aureus for endothelial cells may not be major determinants of metastatic infection.

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 Gamma Interferon Confers Resistance to Infection with Staphylococcus aureus in Human Vascular Endothelial Cells by Cooperative Proinflammatory and Enhanced Intrinsic Antibacterial Activities

2007 ◽  
Vol 75 (12) ◽  
pp. 5615-5626 ◽  
Author(s):  
Henry Beekhuizen ◽  
Joke S. van de Gevel
Keyword(s):  
Staphylococcus Aureus ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Protective Efficacy ◽  
Umbilical Vein ◽  
Effective Means ◽  
Antibacterial Activities ◽  
Gamma Interferon ◽  
Ifn Γ ◽  
Umbilical Vein Endothelial Cells

ABSTRACT Vascular endothelium is an exposed target in systemic endovascular Staphylococcus aureus infections. We reported earlier that the proinflammatory and procoagulant activities of primary human umbilical vein endothelial cells (ECs) after binding and ingestion of S. aureus organisms provide the cells effective means for leukocyte-mediated bacterial elimination. Expanding on this, we now show that these ECs exhibit a modest intrinsic capacity for eliminating intracellular S. aureus that was influenced by cytokines relevant to S. aureus infections. Using various EC infection assays, we showed that gamma interferon (IFN-γ), applied to cultures of ECs prior to or after infection with S. aureus, markedly reduced the level of infection, illustrated by lower percentages of S. aureus-infected ECs and less intracellular bacteria per infected cell. IFN-γ-activated ECs had unaltered abilities to bind S. aureus and processed ingested bacteria by a seemingly conventional phagocytic pathway. IFN-γ treatment rescued EC monolayers from severe injury by virulent clinical S. aureus strains or excessive bacterial numbers. Mechanistically, IFN-γ controls S. aureus infection via IFN-γ receptor, most likely through stimulation of intrinsic endothelial antibacterial mechanisms but independent of processes that deprive bacteria of intracellular l-tryptophan or iron. The antibacterial activity of IFN-γ-stimulated ECs coincided with sustained or slightly elevated endothelial proinflammatory responses that supported monocyte recruitment. In conclusion, we identify IFN-γ as a potent regulatory Th1 cytokine possessing exclusive abilities to augment intrinsic antistaphylocccal effector mechanisms in human ECs without ablating the S. aureus-induced proinflammatory EC responses and, as such, coordinating a protective efficacy of ECs against blood-borne S. aureus infection.

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.

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.

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 KDR activation is crucial for VEGF165-mediated Ca2+mobilization in human umbilical vein endothelial cells

1999 ◽  
Vol 276 (1) ◽  
pp. C176-C181 ◽  
Author(s):  
Sonia A. Cunningham ◽  
Tuan M. Tran ◽  
M. Pia Arrate ◽  
Robert Bjercke ◽  
Tommy A. Brock
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Tyrosine Kinase ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Vascular Endothelial ◽  
Human Umbilical Vein ◽  
Intracellular Ca ◽  
Umbilical Vein Endothelial Cells

We have prepared a polyclonal mouse antibody directed against the first three immunoglobulin-like domains of the kinase insert domain-containing receptor (KDR) tyrosine kinase. It possesses the ability to inhibit binding of the 165-amino acid splice variant of vascular endothelial cell growth factor (VEGF165) to recombinant KDR in vitro as well as to reduce VEGF165binding to human umbilical vein endothelial cells (HUVEC). These results confirm that the first three immunoglobulin-like domains of KDR are involved in VEGF165interactions. The anti-KDR antibody is able to completely block VEGF165-mediated intracellular Ca2+mobilization in HUVEC. Therefore, it appears that binding of VEGF165to the fms-like tyrosine kinase (Flt-1) in these cells does not translate into a Ca2+response. This is further exemplified by the lack of response to placental growth factor (PlGF), an Flt-1-specific ligand. Additionally, PlGF is unable to potentiate the effects of submaximal concentrations of VEGF165. Surprisingly, the VEGF-PlGF heterodimer was also very inefficient at eliciting a Ca2+signaling event in HUVEC. We conclude that KDR activation is crucial for mobilization of intracellular Ca2+in HUVEC in response to VEGF165.

scholarly journals Microcapsules functionalized with neuraminidase can enter vascular endothelial cells in vitro

2014 ◽  
Vol 11 (101) ◽  
pp. 20141027 ◽  
Author(s):  
Weizhi Liu ◽  
Xiaocong Wang ◽  
Ke Bai ◽  
Miao Lin ◽  
Gleb Sukhorukov ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Endothelial Cells ◽  
Mechanical Stability ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Three Dimensional ◽  
Endothelial Barrier ◽  
Live Cells ◽  
Umbilical Vein Endothelial Cells

Microcapsules made of polyelectrolyte multilayers exhibit no or low toxicity, appropriate mechanical stability, variable controllable degradation and can incorporate remote release mechanisms triggered by various stimuli, making them well suited for targeted drug delivery to live cells. This study investigates interactions between microcapsules made of synthetic (i.e. polystyrenesulfonate sodium salt/polyallylamine hydrochloride) or natural (i.e. dextran sulfate/poly- l -arginine) polyelectrolyte and human umbilical vein endothelial cells with particular focus on the effect of the glycocalyx layer on the intake of microcapsules by endothelial cells. Neuraminidase cleaves N -acetyl neuraminic acid residues of glycoproteins and targets the sialic acid component of the glycocalyx on the cell membrane. Three-dimensional confocal images reveal that microcapsules, functionalized with neuraminidase, can be internalized by endothelial cells. Capsules without neuraminidase are blocked by the glycocalyx layer. Uptake of the microcapsules is most significant in the first 2 h. Following their internalization by endothelial cells, biodegradable DS/PArg capsules rupture by day 5; however, there is no obvious change in the shape and integrity of PSS/PAH capsules within the period of observation. Results from the study support our hypothesis that the glycocalyx functions as an endothelial barrier to cross-membrane movement of microcapsules. Neuraminidase-loaded microcapsules can enter endothelial cells by localized cleavage of glycocalyx components with minimum disruption of the glycocalyx layer and therefore have high potential to act as drug delivery vehicles to reach tissues beyond the endothelial barrier of blood vessels.

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