scholarly journals Ethyl Acetate Fraction of Teucrium Polium Extract Abolishes Human Umbilical Vein Endothelial Cells (HUVEC) Tubulogenesis in Collagen Bed through Suppression of Cell Proliferation/VEGF Secretion

2019 ◽  
Author(s):  
Vahide Askari ◽  
Somayeh Shamlou ◽  
Ali Mostafaie ◽  
Sara Khaleqi
Keyword(s):  
Endothelial Cells ◽  
Ethyl Acetate ◽  
Umbilical Vein ◽  
Ethyl Acetate Fraction ◽  
Dependent Manner ◽  
Angiogenic Effect ◽  
Teucrium Polium ◽  
Umbilical Vein Endothelial Cells ◽  
Dose Dependent

Angiogenesis has essential role in growth and metastasis of tumors. Development of therapies aimed to suppress angiogenesis using medicinal plants is one of the effective approaches for prevention/treatment of cancer. The current study was performed to investigate in vitro anti-angiogenic effect of Teucrium Polium (TP) extract and its fractions. The aerial part of Teucrium Polium was powdered and extracted with 50% ethanol. The extract was fractionated in to aqueous (AQ), n-butanol (BU), ethyl acetate (EA) and n-hexane (HE) fractions. Anti-angiogenic effect of TP was examined on human umbilical vein endothelial cells (HUVECs) in three-dimensional collagen matrix. The endothelial cells form capillary-like branches that can be visualized using phase contrast microscope and the number of tube-like structures can be quantified as a measure of in vitro angiogenesis. Furthermore, anti-proliferative and vascular endothelial growth factor(VEGF )suppressive effect of TP as important factors in the process of angiogenesis were assessed using3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)and quantitative ELISA, respectively. Based on our findings, among the TP fractions, EA fraction showed the highest inhibitory activity on angiogenesis. This fraction with IC50: 68 µg/mL, inhibited angiogenesis at 60 µg/mL. The crude extract and other fractions of TP inhibited angiogenesis in a dose-dependent manner at doses higher concentrations than EA fraction, significantly.TP extract and EA fraction were able to inhibit proliferation of HUVEC and inhibited VEGF secretion in a dose dependent manner. The ethyl acetate fraction at 60 µg/ml inhibited VEGF secretion perfectly. Our data indicated that ethyl acetate fraction of Teucrium Polium could be a potential candidate for the prevention of angiogenesis in cancer and other related disorders. However, this suggestion needs more quantitative and in vivo investigations for confirmation.

scholarly journals Alchornea glandulosa Ethyl Acetate Fraction Exhibits Antiangiogenic Activity: Preliminary Findings from In Vitro Assays Using Human Umbilical Vein Endothelial Cells

2011 ◽  
Vol 14 (10) ◽  
pp. 1244-1253 ◽  
Author(s):  
Flávia Cristine Mascia Lopes ◽  
Ana Rocha ◽  
Ana Pirraco ◽  
Luis O. Regasini ◽  
Janaina R. Siqueira ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ethyl Acetate ◽  
Umbilical Vein ◽  
Ethyl Acetate Fraction ◽  
In Vitro Assays ◽  
Human Umbilical Vein ◽  
Antiangiogenic Activity ◽  
Umbilical Vein Endothelial Cells

scholarly journals Endothelial AMP-Activated Kinase α1 Phosphorylates eNOS on Thr495 and Decreases Endothelial NO Formation

2018 ◽  
Vol 19 (9) ◽  
pp. 2753 ◽  
Author(s):  
Nina Zippel ◽  
Annemarieke Loot ◽  
Heike Stingl ◽  
Voahanginirina Randriamboavonjy ◽  
Ingrid Fleming ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Reactivity ◽  
Umbilical Vein ◽  
No Production ◽  
Dependent Manner ◽  
Calmodulin Binding ◽  
Umbilical Vein Endothelial Cells ◽  
Endothelial Nitric Oxide ◽  
Specific Deletion

AMP-activated protein kinase (AMPK) is frequently reported to phosphorylate Ser1177 of the endothelial nitric-oxide synthase (eNOS), and therefore, is linked with a relaxing effect. However, previous studies failed to consistently demonstrate a major role for AMPK on eNOS-dependent relaxation. As AMPK also phosphorylates eNOS on the inhibitory Thr495 site, this study aimed to determine the role of AMPKα1 and α2 subunits in the regulation of NO-mediated vascular relaxation. Vascular reactivity to phenylephrine and acetylcholine was assessed in aortic and carotid artery segments from mice with global (AMPKα−/−) or endothelial-specific deletion (AMPKαΔEC) of the AMPKα subunits. In control and AMPKα1-depleted human umbilical vein endothelial cells, eNOS phosphorylation on Ser1177 and Thr495 was assessed after AMPK activation with thiopental or ionomycin. Global deletion of the AMPKα1 or α2 subunit in mice did not affect vascular reactivity. The endothelial-specific deletion of the AMPKα1 subunit attenuated phenylephrine-mediated contraction in an eNOS- and endothelium-dependent manner. In in vitro studies, activation of AMPK did not alter the phosphorylation of eNOS on Ser1177, but increased its phosphorylation on Thr495. Depletion of AMPKα1 in cultured human endothelial cells decreased Thr495 phosphorylation without affecting Ser1177 phosphorylation. The results of this study indicate that AMPKα1 targets the inhibitory phosphorylation Thr495 site in the calmodulin-binding domain of eNOS to attenuate basal NO production and phenylephrine-induced vasoconstriction.

Decrease of tetrahydrobiopterin and NO generation in endothelial cells exposed to simulated diving

2019 ◽  
pp. 159-169
Author(s):  
Ronja Hesthammer ◽  
◽  
Torunn Eide ◽  
Eimar Thorsen ◽  
Asbjørn M. Svardal ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Decompression Sickness ◽  
Synergistic Effects ◽  
Umbilical Vein ◽  
Bubble Formation ◽  
No Production ◽  
Dependent Manner ◽  
Hyperoxic Exposure ◽  
Umbilical Vein Endothelial Cells ◽  
Dose Dependent

Purpose: Nitric oxide (NO) has been shown to protect against bubble formation and the risk of decompression sickness. We hypothesize that oxidation of tetrahydrobiopterin (BH4) leads to a decreased production of NO during simulated diving. Methods: Human umbilical vein endothelial cells (HUVEC) were exposed to hyperoxia or simulated diving for 24 hours. The levels of biopterins (BH4, BH2 and B) were determined by LC-MS/MS, and the production of NO by monitoring the conversion of L-arginine to L-citrulline. Results: Exposure to hyperoxia decreased BH4 in a dose-dependent manner; by 48 ± 15% following exposure to 40 kPa O2 (P < 0.001 vs. control at 20 kPa O2), and 70 ± 16% following exposure to 60 kPa O2. Exposure to 40 kPa O2 decreased NO production by 25 ± 9%, but there was no further decrease when increasing oxygen exposure to 60 kPa (25 ± 10%). No additional effects of simulated diving were observed, indicating no additive or synergistic effects of hyperbaria and hyperoxia on the BH4 level or NO generation. Conclusion: NO generation in intact human endothelial cells was decreased by simulated diving, as well as by hyperoxic exposure, while BH4 levels seem to be affected only by hyperoxia. Hence, the results suggest that BH4 is not the sole determinant of NO generation in HUVEC.

scholarly journals PPAR-αAgonist Fenofibrate Upregulates Tetrahydrobiopterin Level through Increasing the Expression of Guanosine 5′-Triphosphate Cyclohydrolase-I in Human Umbilical Vein Endothelial Cells

PPAR Research ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jinbo Liu ◽  
Changlin Lu ◽  
Fuwang Li ◽  
Haining Wang ◽  
Liyun He ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Control Group ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Tetrahydrobiopterin (BH4) is an essential cofactor for endothelial nitric oxide (NO) synthase. Guanosine 5′-triphosphate cyclohydrolase-I (GTPCH-I) is a key limiting enzyme for BH4 synthesis. In the present in vitro study, we investigated whether peroxisome proliferator-activated receptorα(PPAR-α) agonist fenofibrate could recouple eNOS by reversing low-expression of intracellular BH4 in endothelial cells and discussed the potential mechanisms. After human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) for 24 hours, the levels of cellular eNOS, BH4 and cell supernatant NO were significantly reduced compared to control group. And the fluorescence intensity of intracellular ROS was significantly increased. But pretreated with fenofibrate (10 umol/L) for 2 hours before cells were induced by LPS, the levels of eNOS, NO, and BH4 were significantly raised compared to LPS treatment alone. ROS production was markedly reduced in fenofibrate group than LPS group. In addition, our results showed that the level of intracellular GTPCH-I detected by western blot was increased in a concentration-dependent manner after being treated with fenofibrate. These results suggested that fenofibrate might help protect endothelial function and against atherosclerosis by increasing level of BH4 and decreasing production of ROS through upregulating the level of intracellular GTPCH-I.

Purification, molecular cloning and mechanism of action of graminelysin I, a snake-venom-derived metalloproteinase that induces apoptosis of human endothelial cells

2001 ◽  
Vol 357 (3) ◽  
pp. 719-728 ◽  
Author(s):  
Wen Bin WU ◽  
Shin C. CHANG ◽  
Ming-Yi LIAU ◽  
Tur-Fu HUANG
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Matrix Proteins ◽  
Dependent Manner ◽  
Single Chain ◽  
Human Endothelial Cells ◽  
Putative Precursor ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells ◽  
Dose Dependent

Apoptosis, a programmed, physiological mode of cell death, is important in tissue homoeostasis. Here we report that a new metalloproteinase, graminelysin I, purified from Trimeresurus gramineus venom, induced apoptosis of human endothelial cells as examined by electrophoresis and flow cytometry. Graminelysin I contains only a metalloproteinase domain. It is a single-chain proteinase with a molecular mass of 27020Da. cDNA sequence analysis revealed that the disintegrin-like and cysteine-rich domains of the putative precursor protein of graminelysin I are likely to be processed post-translationally, producing the proteinase domain (graminelysin I). Graminelysin I cleaved the α chain of fibrinogen preferentially and cleaved the β chain either on longer incubation or at higher concentration. Graminelysin I inhibited the adhesion of human umbilical-vein endothelial cells (HUVECs) to immobilized fibrinogen and induced HUVECs detachment in a dose-dependent manner. These effects on HUVECs were abolished when graminelysin I was pretreated with EDTA. However, graminelysin I did not inhibit the adhesion of HUVECs to immobilized collagen. HUVECs were susceptible to death after treatment with graminelysin I when they were cultured on immobilized fibrinogen. In contrast, HUVECs were rather resistant to treatment with graminelysin I if they were cultured on immobilized collagen. Furthermore, graminelysin I induced apoptosis of HUVECs in a dose-dependent manner. Similarly, its apoptosis-inducing activity was blocked if it was treated with EDTA. These results suggest that the catalytic activity of graminelysin I on matrix proteins contributes to its apoptosis-inducing activity.

scholarly journals Shear-dependent inhibition of granulocyte adhesion to cultured endothelium by dextran sulfate

Blood ◽  
1989 ◽  
Vol 73 (5) ◽  
pp. 1324-1330
Author(s):  
K Ley ◽  
E Lundgren ◽  
E Berger ◽  
KE Arfors
Keyword(s):  
Shear Stress ◽  
Dextran Sulfate ◽  
Leukocyte Adhesion ◽  
Umbilical Vein ◽  
Dependent Manner ◽  
Dependent Inhibition ◽  
Umbilical Vein Endothelial Cells ◽  
Dose Dependent ◽  
Adhesion Process

Adhesion of polymorphonuclear granulocytes (PMNs) in microvessels occurs in the presence of shear forces exerted by the blood flow. To model this in vitro, phorbol myristate acetate (PMA)-activated PMN were exposed to shear stress on cultured human umbilical vein endothelial cells (HUVECs) and on plastic dishes coated with bovine serum albumin (BSA). PMN adhesion to HUVECs averaged 36% of the total PMNs added and was reduced to 21% by shear stress of approximately 1.5 dynes.cm-2. On BSA, adhesion was reduced from 59% to 35%. Dextran sulfate (molecular weight 500,000) inhibited PMN adhesion in a dose-dependent manner when shear stress was applied. At a concentration of 1 mg.ml-1, inhibition was 72% on HUVECs and 76% on BSA. Half-maximal inhibition was reached at approximately 1 microgram.mL-1 dextran sulfate, corresponding to 2 nmol/L. Without shear stress, dextran sulfate had no effect on HUVECs and only a moderate effect on BSA. The murine monoclonal antibody (MoAb) 60.3, recognizing an epitope on the leukocyte adhesion glycoprotein CD18, inhibited PMN adhesion equally well with and without shear. A low dose of MoAb 60.3 enhanced the effect of dextran sulfate without shear stress. Flow cytometry (FACS) did not show inhibition of MoAb 60.3 binding to PMNs by dextran sulfate. These results indicate that a dextran sulfate-inhibitable adhesion process is important for PMN adhesion in the presence of shear stress.

Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4293-4299 ◽  
Author(s):  
Nobuo Hisano ◽  
Yutaka Yatomi ◽  
Kaneo Satoh ◽  
Shigeo Akimoto ◽  
Masako Mitsumata ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Cell Interaction ◽  
Dependent Manner ◽  
Survival Factor ◽  
Highly Active ◽  
Sphingosine 1 Phosphate ◽  
Umbilical Vein Endothelial Cells

Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.

Defibrotide Stimulates Expression of Thrombomodulin in Human Endothelial Cells

1994 ◽  
Vol 71 (04) ◽  
pp. 507-510 ◽  
Author(s):  
Quansheng Zhou ◽  
Xiaohong Chu ◽  
Changgeng Ruan
Keyword(s):  
Endothelial Cells ◽  
Conditioned Medium ◽  
Umbilical Vein ◽  
Dependent Manner ◽  
Human Endothelial Cells ◽  
Antithrombotic Activity ◽  
Beneficial Effects ◽  
Chromogenic Assay ◽  
Umbilical Vein Endothelial Cells ◽  
Dose Dependent

SummaryCultured human umbilical vein endothelial cells were incubated with defibrotide at concentrations of 0, 5, 50 and 500 jxg/ml for 4 and 24 h respectively. Thrombomodulin activity and molecules on the surface of the cells were determined by chromogenic assay and radioimmunoassay, thrombomodulin antigen in endothelial cells and in conditioned medium of the cells was measured by immunoradioassay. Thrombomodulin mRNA within the cells was analysed by slot blot. After 24 h of incubation, the activity and molecules of thrombomodulin on the surface of endothelial cells, as well as the antigen and mRNA of thrombomodulin in the cells were significantly increased in a dose dependent manner. However, the level of thrombomodulin antigen in conditioned medium was about equal to that of the control. Our data indicate that defibrotide stimulates expression of thrombomodulin in human endothelial cells. These beneficial effects may play a role in antithrombotic activity of defibrotide.

Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4293-4299 ◽  
Author(s):  
Nobuo Hisano ◽  
Yutaka Yatomi ◽  
Kaneo Satoh ◽  
Shigeo Akimoto ◽  
Masako Mitsumata ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Cell Interaction ◽  
Dependent Manner ◽  
Survival Factor ◽  
Highly Active ◽  
Sphingosine 1 Phosphate ◽  
Umbilical Vein Endothelial Cells

Abstract Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.

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