scholarly journals Invasion of Aortic and Heart Endothelial Cells byPorphyromonas gingivalis

1998 ◽  
Vol 66 (11) ◽  
pp. 5337-5343 ◽  
Author(s):  
Rajashri G. Deshpande ◽  
Mahfuz B. Khan ◽  
Caroline Attardo Genco
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Protein Synthesis ◽  
De Novo ◽  
Umbilical Vein ◽  
Host Cells ◽  
Periodontal Pathogen ◽  
Host Immune System ◽  
Umbilical Vein Endothelial Cells ◽  
De Novo Protein Synthesis

ABSTRACT Invasion of host cells is believed to be an important strategy utilized by a number of pathogens, which affords them protection from the host immune system. The connective tissues of the periodontium are extremely well vascularized, which allows invading microorganisms, such as the periodontal pathogen Porphyromonas gingivalis, to readily enter the bloodstream. However, the ability of P. gingivalis to actively invade endothelial cells has not been previously examined. In this study, we demonstrate that P. gingivalis can invade bovine and human endothelial cells as assessed by an antibiotic protection assay and by transmission and scanning electron microscopy. P. gingivalis A7436 was demonstrated to adhere to and to invade fetal bovine heart endothelial cells (FBHEC), bovine aortic endothelial cells (BAEC), and human umbilical vein endothelial cells (HUVEC). Invasion efficiencies of 0.1, 0.2, and 0.3% were obtained with BAEC, HUVEC, and FBHEC, respectively. Invasion of FBHEC and BAEC by P. gingivalis A7436 assessed by electron microscopy revealed the formation of microvillus-like extensions around adherent bacteria followed by the engulfment of the pathogen within vacuoles. Invasion of BAEC by P. gingivalisA7436 was inhibited by cytochalasin D, nocodazole, staurosporine, protease inhibitors, and sodium azide, indicating that cytoskeletal rearrangements, protein phosphorylation, energy metabolism, andP. gingivalis proteases are essential for invasion. In contrast, addition of rifampin, nalidixic acid, and chloramphenicol had little effect on invasion, indicating that bacterial RNA, DNA, and de novo protein synthesis are not required for P. gingivalisinvasion of endothelial cells. Likewise de novo protein synthesis by endothelial cells was not required for invasion by P. gingivalis. P. gingivalis 381 was demonstrated to adhere to and to invade BAEC (0.11 and 0.1% efficiency, respectively). However, adherence and invasion of the corresponding fimA mutant DPG3, which lacks the major fimbriae, was not detected. These results indicate thatP. gingivalis can actively invade endothelial cells and that fimbriae are required for this process. P. gingivalisinvasion of endothelial cells may represent another strategy utilized by this pathogen to thwart the host immune response.

Platelets Stimulate Thromboplastin Synthesis in Human Endothelial Cells

1983 ◽  
Vol 49 (02) ◽  
pp. 069-072 ◽  
Author(s):  
U L H Johnsen ◽  
T Lyberg ◽  
K S Galdal ◽  
H Prydz
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Umbilical Vein ◽  
Time Dependent ◽  
De Novo Synthesis ◽  
Human Endothelial Cells ◽  
Tumor Promotor ◽  
Coagulation Assay ◽  
Platelet Aggregates ◽  
Umbilical Vein Endothelial Cells

SummaryHuman umbilical vein endothelial cells in culture synthesize thromboplastin upon stimulation with phytohaemagglutinin (PHA) or the tumor promotor 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The thromboplastin activity is further strongly enhanced in a time dependent reaction by the presence of gel-filtered platelets or platelet aggregates. This effect was demonstrable at platelet concentrations lower than those normally found in plasma, it may thus be of pathophysiological relevance. The thromboplastin activity increased with increasing number of platelets added. Cycloheximide inhibited the increase, suggesting that de novo synthesis of the protein component of thromboplastin, apoprotein III, is necessary.When care was taken to remove monocytes no thromboplastin activity and no apoprotein HI antigen could be demonstrated in suspensions of gel-filtered platelets, platelets aggregated with thrombin or homogenized platelets when studied with a coagulation assay and an antibody neutralization technique.

scholarly journals Facile Synthesis, Characterization, Photocatalytic Activity, and Cytotoxicity of Ag-Doped MgO Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2915
Author(s):  
ZabnAllah M. Alaizeri ◽  
Hisham A. Alhadlaq ◽  
Saad Aldawood ◽  
Mohd Javed Akhtar ◽  
Mabrook S. Amer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Photocatalytic Activity ◽  
Environmental Remediation ◽  
Metal Ion ◽  
Umbilical Vein ◽  
Facile Synthesis ◽  
X Ray ◽  
Cytotoxicity Studies ◽  
Umbilical Vein Endothelial Cells

Due to unique physicochemical properties, magnesium oxide nanoparticles (MgO NPs) have shown great potential for various applications, including biomedical and environmental remediation. Moreover, the physiochemical properties of MgO NPs can be tailored by metal ion doping that can be utilized in photocatalytic performance and in the biomedical field. There is limited study on the photocatalytic activity and biocompatibility of silver (Ag)-doped MgO NPs. This study was planned for facile synthesis, characterization, and photocatalytic activity of pure and silver (Ag)-doped MgO NPs. In addition, cytotoxicity of pure and Ag-doped MgO NPs was assessed in human normal umbilical vein endothelial cells (HUVECs). Pure MgO NPs and Ag-doped (1, 2, 5, and 7.5 mol%) MgO NPs were prepared via a simple sol-gel procedure. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared samples. XRD results showed the preparation of highly crystalline NPs with no impurity peaks. TEM and SEM studies indicate smooth surfaces with almost spherical morphology of MgO NPs, and Ag-doping did not change the morphology. Elemental composition study suggested that Ag is uniformly distributed in MgO particles. Intensity of the PL spectra of MgO NPs decreased with increasing the concentration of Ag dopants. In comparison to pure MgO NPs, Ag-MgO NPs showed higher degradation of methylene blue (MB) dye under UV irradiation. The improved photocatalytic activity of Ag-MgO NPs was related to the effect of dopant concentration on reducing the recombination between electrons and holes. Cytotoxicity studies showed good biocompatibility of pure and Ag-doped MgO NPs with human normal umbilical vein endothelial cells (HUVECs). These results highlighted the potential of Ag-doped MgO NPs in environmental remediation.

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 E-Selectin Mediates Porphyromonas gingivalis Adherence to Human Endothelial Cells

2012 ◽  
Vol 80 (7) ◽  
pp. 2570-2576 ◽  
Author(s):  
Toshinori Komatsu ◽  
Keiji Nagano ◽  
Shinsuke Sugiura ◽  
Makoto Hagiwara ◽  
Naomi Tanigawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Porphyromonas Gingivalis ◽  
Umbilical Vein ◽  
Vascular Inflammation ◽  
Periodontal Pathogen ◽  
Sialyl Lewis X ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Umbilical Vein Endothelial Cells

ABSTRACTPorphyromonas gingivalis, a major periodontal pathogen, may contribute to atherogenesis and other inflammatory cardiovascular diseases. However, little is known about interactions betweenP. gingivalisand endothelial cells. E-selectin is a membrane protein on endothelial cells that initiates recruitment of leukocytes to inflamed tissue, and it may also play a role in pathogen attachment. In the present study, we examined the role of E-selectin inP. gingivalisadherence to endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with tumor necrosis factor alpha (TNF-α) to induce E-selectin expression. Adherence ofP. gingivalisto HUVECs was measured by fluorescence microscopy. TNF-α increased adherence of wild-typeP. gingivalisto HUVECs. Antibodies to E-selectin and sialyl Lewis X suppressedP. gingivalisadherence to stimulated HUVECs.P. gingivalismutants lacking OmpA-like proteins Pgm6 and -7 had reduced adherence to stimulated HUVECs, but fimbria-deficient mutants were not affected. E-selectin-mediatedP. gingivalisadherence activated endothelial exocytosis. These results suggest that the interaction between host E-selectin and pathogen Pgm6/7 mediatesP. gingivalisadherence to endothelial cells and may trigger vascular inflammation.

Tissue Kallikrein KLK1 Is Expressed de Novo in Endothelial Cells and Mediates Relaxation of Human Umbilical Veins

2001 ◽  
Vol 382 (10) ◽  
pp. 1483-1490 ◽  
Author(s):  
J. Dedio ◽  
G. Wiemer ◽  
H. Rütten ◽  
A. Dendorfer ◽  
B.A. Schölkens ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Umbilical Vein ◽  
Exchange Chromatography ◽  
Partial Purification ◽  
Tissue Kallikrein ◽  
Kinin System ◽  
Western Blots ◽  
Cell Extracts ◽  
Umbilical Vein Endothelial Cells

AbstractBradykinin released by the endothelium is thought to play an important local role in cardiovascular regulation. However, the molecular identity of endothelial proteases liberating bradykinin from its precursors remained unclear. Using RTPCR and Southern blotting techniques we detected mRNA for tissue kallikrein (KLK1) in human umbilical vein endothelial cells and in bovine aortic endothelial cells. Protein expression was confirmed by precipitation of KLK1 from lysates of endothelial cells prelabeled with [35S]cysteine/methionine. Partial purification of tissue kallikrein from total endothelial cell extracts resulted in a protein triplet of about 50 kDa in Western blots using specific antiKLK1 antibodies. The immunodetection of tissue kallikrein antigen in the fractions from ion exchange chromatography correlated with the presence of amidolytic tissue kallikrein activity. Stimulation of endothelial cells with angiotensin II (ANGII), which recently has been shown to activate the vascular kinin system and to cause vasodilation, resulted in the release of bradykinin and kallidin. ANGIIdependent relaxation of preconstricted rings from human umbilical veins was abolished in the presence of a specific tissue kallikrein inhibitor. We conclude that endothelial cells de novo express significant amounts of tissue kallikrein, which likely serves in the local generation of vasoactive kinins.

scholarly journals MicroRNA-494 Regulates Endoplasmic Reticulum Stress in Endothelial Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Namita Chatterjee ◽  
Eugenia Fraile-Bethencourt ◽  
Adrian Baris ◽  
Cristina Espinosa-Diez ◽  
Sudarshan Anand
Keyword(s):  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Stress Responses ◽  
De Novo ◽  
Umbilical Vein ◽  
Critical Role ◽  
Umbilical Vein Endothelial Cells ◽  
And Control

Defects in stress responses are important contributors in many chronic conditions including cancer, cardiovascular disease, diabetes, and obesity-driven pathologies like non-alcoholic steatohepatitis (NASH). Specifically, endoplasmic reticulum (ER) stress is linked with these pathologies and control of ER stress can ameliorate tissue damage. MicroRNAs have a critical role in regulating diverse stress responses including ER stress. Here, we show that miR-494 plays a functional role during ER stress. Pharmacological ER stress inducers (tunicamycin (TCN) and thapsigargin) and hyperglycemia robustly increase the expression of miR-494 in vitro. ATF6 impacts the primary miR-494 levels whereas all three ER stress pathways are necessary for the increase in mature miR-494. Surprisingly, miR-494 pretreatment dampens the induction and magnitude of ER stress in response to TCN in endothelial cells and increases cell viability. Conversely, inhibition of miR-494 increases ER stress de novo and amplifies the effects of ER stress inducers. Using Mass Spectrometry (TMT-MS) we identified 23 proteins that are downregulated by both TCN and miR-494 in cultured human umbilical vein endothelial cells. Among these, we found 6 transcripts which harbor a putative miR-494 binding site. We validated the anti-apoptotic gene BIRC5 (survivin) and GINS4 as targets of miR-494 during ER stress. In summary, our data indicates that ER stress driven miR-494 may act in a feedback inhibitory loop to dampen downstream ER stress signaling.

scholarly journals Verocytotoxin-Induced Apoptosis of Human Microvascular Endothelial Cells

2001 ◽  
Vol 12 (4) ◽  
pp. 767-778
Author(s):  
ANTONETTA H. J. M. PIJPERS ◽  
PETRA A. VAN SETTEN ◽  
LAMBERTUS P. W. J. VAN DEN HEUVEL ◽  
KAREL J. M. ASSMANN ◽  
HENDRIKUS B. P. M. DIJKMAN ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Protein Synthesis ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Microvascular Endothelial Cells ◽  
Tnf Α ◽  
Microvascular Endothelial ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Abstract. The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-α (TNF-α). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-α interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-α-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

Observations on the Cell Biology of Tissue Factor in Endothelial Cells

1990 ◽  
Vol 63 (02) ◽  
pp. 298-302 ◽  
Author(s):  
Kiyoshi Andoh ◽  
Kjell Sverre Pettersen ◽  
Christiane Filion -Myklebust ◽  
Hans Prydz
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Plasma Membrane ◽  
Tissue Factor ◽  
Cell Biology ◽  
Umbilical Vein ◽  
Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

SummaryHuman umbilical vein endothelial cells (HUVEC) are inducible for tissue factor (TF) activity in culture. Based on experiments using ECGF (4–20 µg/ml) with heparin (90 µg/ml), we obtained the followingresults: 1) In confluent HUVEC cultures, ECGF had essentially no influence on the levels of inducible TF. 2) In growing HUVEC cultures, ECGF reduced the TF response shortly after seeding but full response was regained when cells were kept confluent for 2–3 days. 3) Although secondary cultures responded best to TF induction in the absence of ECGF, the response was essentially equal over at least 8 passages in the prcgcncc of ECGF 1) Of total cellular TF induced in HUVEC, about 25% was available on the surface, and less than 4% was released with theshed plasma membrane vesicles. The proportion of total TF a>ctivity available on the surface of mtact cells wasnot influenced by the presence of ECGF 5) T½, for the decay of TF activity induced was 8.3—9.5 h, whereas in HUVEC when protein synthesis was blocked afterIF induction a T½ of about 30 h was found.

The Effects of Carnosine on High Glucose-Induced Apoptosis of Human Umbilical Vein Endothelial Cells

2011 ◽  
Vol 345 ◽  
pp. 365-369
Author(s):  
Yan Shi ◽  
Chun Jing Zhang
Keyword(s):  
Electron Microscopy ◽  
Flow Cytometry ◽  
Endothelial Cells ◽  
High Glucose ◽  
Umbilical Vein ◽  
Control Group ◽  
Human Umbilical Vein ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

.Purposes,To explore the effects of carnosine on high glucose-induced apoptosis of human umbilical vein endothelial cells (HUVECs). Methods HUVECs were cultured in vitro. The cellular apoptotic model was made by the addition of high glucose (25 mmol/L), the group of high glucose and carnosine was administered by the addition of high glucose (25 mmol/L) with carnosine (20 mmol/L). In addition, cell apoptosis was detected by the electron microscopy and AnnexinV/PI flow cytometry. Results Compared with the control group, high glucose could induce HUVECs apoptosis under electron microscopy and AnnexinV/PI flow cytometry, while 20 mmol/L carnosine could inhibit the apoptosis induced by high glucose significantly (##P <0.05). Conclusion In this study, carnosine could inhibit high-glucose induced apoptosis of human umbilical vein endothelial cells.

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