scholarly journals Rhizopus oryzae Adheres to, Is Phagocytosed by, and Damages Endothelial Cells In Vitro

2005 ◽  
Vol 73 (2) ◽  
pp. 778-783 ◽  
Author(s):  
Ashraf S. Ibrahim ◽  
Brad Spellberg ◽  
Valentina Avanessian ◽  
Yue Fu ◽  
John E. Edwards
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Rhizopus Oryzae ◽  
Vascular Endothelial Cells ◽  
Cell Damage ◽  
Umbilical Vein ◽  
Tissue Necrosis ◽  
Life Threatening ◽  
Umbilical Vein Endothelial Cells

ABSTRACT Rhizopus oryzae is the most common cause of zygomycosis, a life-threatening infection that usually occurs in immunocompromised patients. A characteristic hallmark of zygomycosis is angioinvasion by the fungus, resulting in thrombosis and subsequent tissue necrosis. Interactions between R. oryzae and vascular endothelial cells are therefore likely of central importance to the organism's pathogenetic strategy. We studied the ability of R. oryzae to adhere to and damage human umbilical vein endothelial cells (HUVECs) in vitro. We report that R. oryzae spores and germ tubes adhere to HUVECs, whereas only spores adhere to subendothelial matrix proteins. Additionally, R. oryzae damages endothelial cells. This endothelial cell damage requires direct contact and subsequent phagocytosis of the fungus. Surprisingly, R. oryzae viability was not required for damage, but phagocytosis was required for dead R. oryzae to cause damage. These results elucidate the nature of R. oryzae-endothelial cell interactions, which are likely central to the angioinvasion and tissue necrosis seen during zygomycotic infections. The fact that dead R. oryzae damage human endothelial cells may, in part, explain the lack of efficacy of fungicidal agents during clinical disease.

Panax Quinquefolium L. Inhibits Thrombin-Induced Endothelin Release In Vitro

1999 ◽  
Vol 27 (03n04) ◽  
pp. 331-338 ◽  
Author(s):  
Chun-Su Yuan ◽  
Anoja S. Attele ◽  
Ji An Wu ◽  
Tasha K. Lowell ◽  
Zhenlun Gu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Cell Damage ◽  
Umbilical Vein ◽  
American Ginseng ◽  
Protective Effects ◽  
Panax Quinquefolium

Endothelial cell damage is considered to be the initial step in the genesis of thrombosis and arteriosclerosis, the common precursors of cardiovascular disorders. In this study, we evaluated the protective effects of American ginseng or Panax quinquefolium L. extracts on endothelial cell injury, and investigated effects of ginseng extracts on thrombin-induced endothelin release using cultured human umbilical vein endothelial cells. We observed that when endothelial cells pretreated with 1, 10, and 100 μg/ml of Panax quinquefolium L. extracts were incubated for 4 and 24 hr with thrombin, the concentration of endothelin was significantly decreased in a concentration dependent, time related manner (at 4 hr, IC50 = 5.1 μg/ml; at 24 hr, IC50 = 6.2 μg/ml). We further evaluated the effects of NG-nitro-L-arginine (NLA), a nitric oxide (NO) synthetase inhibitor, on the activity of Panax quinquefolium L. extracts. Following pretreatment of cultured endothelial cells with NLA, the inhibition of thrombin-induced endothelin release by Panax quinquefolium L. was significantly reduced (P < 0.05). This result suggests that the pharmacological action of Panax quinquefolium L. is, at least partially, due to NO release. Our data demonstrate that American ginseng may play a therapeutic role in facilitating the hemodynamic balance of vascular endothelial cells.

scholarly journals Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Gap Formation ◽  
Culture Dish ◽  
Cell Monolayers ◽  
Umbilical Vein Endothelial Cells

Abstract When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.

scholarly journals Endothelialized silicone aneurysm models for in vitro evaluation of flow diverters

2020 ◽  
pp. neurintsurg-2020-016859
Author(s):  
Alyssa McCulloch ◽  
Ashley Turcott ◽  
Gabriella Graham ◽  
Sergey Frenklakh ◽  
Kristen O'Halloran Cardinal
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Flow Diverter ◽  
In Vitro Models ◽  
Cell Coverage ◽  
Platelet Endothelial Cell Adhesion ◽  
Umbilical Vein Endothelial Cells ◽  
Over Time

ObjectiveThe goal of this work was to endothelialize silicone aneurysm tubes for use as in vitro models for evaluating endothelial cell interactions with neurovascular devices. The first objective was to establish consistent and confluent endothelial cell linings and to evaluate the silicone vessels over time. The second objective was to use these silicone vessels for flow diverter implantation and assessment.MethodsSilicone aneurysm tubes were coated with fibronectin and placed into individual bioreactor systems. Human umbilical vein endothelial cells were deposited within tubes to create silicone vessels, then cultivated on a peristaltic pump and harvested at 2, 5, 7, or 10 days to evaluate the endothelial cell lining. A subset of silicone aneurysm vessels was used for flow diverter implantation, and evaluated for cell coverage over device struts at 3 or 7 days after deployment.ResultsSilicone vessels maintained confluent, PECAM-1 (platelet endothelial cell adhesion molecule 1) positive endothelial cell linings over time. These vessels facilitated and withstood flow diverter implantation, with robust cell linings disclosed after device deployment. Additionally, the endothelial cells responded to implanted devices through coverage of the flow diverter struts with increased cell coverage over the aneurysm seen at 7 days after deployment as compared with 3 days.ConclusionsSilicone aneurysm models can be endothelialized and successfully maintained in vitro over time. Furthermore, these silicone vessels can be used for flow diverter implantation and assessment.

Modulation Of PGI2-Like Activity Of Human Endothelial Cells By An Extracellular Collagen Matrix

1981 ◽  
Author(s):  
K M Spiegel ◽  
S F Mohammad ◽  
H Y K Chuang ◽  
R G Mason
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Collagen Matrix ◽  
Significant Loss ◽  
Experimental Conditions ◽  
Cell Lysates ◽  
Collagen Coating ◽  
Umbilical Vein Endothelial Cells

Human umbilical vein endothelial cells were grown on several artificial matrices including collagen and on unmodified plastic dishes. Freeze thaw preparations of confluent monolayer endothelial cell cultures were assayed for PGI2-like activity by testing for inhibition of platelet a88regation. The cells grown on a collagen matrix expressed slightly less PGI2-like activity initially compared to the cells grown on plastic. When the PGI2like activity of the cell lysates was examined over a period of three hours after the initial preparation, endothelial cells grown on a collagen matrix exhibited a more rapid loss of activity. Preliminary quantitative evaluations suggest that lysates derived from cells grown on unmodified plastic retained 75% PGI2 like activity at 15 min, at which point collagen grown cells exhibited essentially no PGI2-like activity. Furthermore, as shown in the figure, under identical experimental conditions, cell lysates obtained from endothelial cells grown on unmodified plastic continued to express approximately 50% of the initial PGI2-like activity after one hour. Since addition of purified PGI2 or cell lysates in vitro to the collagen coating used as tissue culture substrate failed to cause any significant loss of platelet aggregation inhibitory activity beyond the normal rate of decay of PGI2 it appears likely that the reduction of PGI2-like activity may be associated with changes in the substrate collagen, possibly effected by the endothelial cell layer. Alternatively, the reduction of activity may be related to differences in the endothelial cells caused by growth on the collagen substrate.

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 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 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.

scholarly journals Immunosuppressive nano-therapeutic micelles downregulate endothelial cell inflammation and immunogenicity

RSC Advances ◽  
2015 ◽  
Vol 5 (54) ◽  
pp. 43552-43562 ◽  
Author(s):  
Satish N. Nadig ◽  
Suraj K. Dixit ◽  
Natalie Levey ◽  
Scott Esckilsen ◽  
Kayla Miller ◽  
...  
Keyword(s):  
Immune Response ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Perfusion Solution ◽  
Umbilical Vein Endothelial Cells

Targeted micelles containing rapamycin (TRaM) suppressed the immune response of IL-8 in oxidatively stressed human umbilical vein endothelial cellsin vitro(a) and accumulated in aorta grafts for transplantation after 6 hours in cold perfusion solution (b).

scholarly journals Flagellar Hook Protein FlgE Induces Microvascular Hyperpermeability via Ectopic ATP Synthase β on Endothelial Surface

2021 ◽  
Vol 11 ◽  
Author(s):  
Yuanyuan Li ◽  
Ying Shen ◽  
Yudan Zheng ◽  
Shundong Ji ◽  
Mengru Wang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Abdominal Cavity ◽  
Tube Formation ◽  
Atp Production ◽  
Endothelial Surface ◽  
Umbilical Vein Endothelial Cells

We previously demonstrated the immunostimulatory efficacy of Pseudomonas aeruginosa flagellar hook protein FlgE on epithelial cells, presumably via ectopic ATP synthases or subunits ATP5B on cell membranes. Here, by using recombinant wild-type FlgE, mutant FlgE (FlgEM; bearing mutations on two postulated critical epitopes B and F), and a FlgE analog in pull-down assay, Western blotting, flow cytometry, and ELISA, actual bindings of FlgE proteins or epitope B/F peptides with ATP5B were all confirmed. Upon treatment with FlgE proteins, human umbilical vein endothelial cells (HUVECs) and SV40-immortalized murine vascular endothelial cells manifested decreased proliferation, migration, tube formation, and surface ATP production and increased apoptosis. FlgE proteins increased the permeability of HUVEC monolayers to soluble large molecules like dextran as well as to neutrophils. Immunofluorescence showed that FlgE induced clustering and conjugation of F-actin in HUVECs. In Balb/c-nude mice bearing transplanted solid tumors, FlgE proteins induced a microvascular hyperpermeability in pinna, lungs, tumor mass, and abdominal cavity. All effects observed in FlgE proteins were partially or completely impaired in FlgEM proteins or blocked by pretreatment with anti-ATP5B antibodies. Upon coculture of bacteria with HUVECs, FlgE was detectable in the membrane and cytosol of HUVECs. It was concluded that FlgE posed a pathogenic ligand of ectopic ATP5B that, upon FlgE–ATP5B coupling on endothelial cells, modulated properties and increased permeability of endothelial layers both in vitro and in vivo. The FlgE-ectopic ATP5B duo might contribute to the pathogenesis of disorders associated with bacterial infection or ectopic ATP5B-positive cells.

scholarly journals Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Gap Formation ◽  
Culture Dish ◽  
Cell Monolayers ◽  
Umbilical Vein Endothelial Cells

When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.

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