ROLE OF BIOLOGICAL RESPONSE MODIFIERSIN THE REGULATION OF THROMBOPLASTIN SYNTHESIS IN MONOCYTES AND ENDOTHELIAL CELLS

1987 ◽  
Author(s):  
E Carlsen ◽  
H Prydz

A rabbit polyclonal antibody which was monospecific for thromboplastin (TP) apoprotein from human brain according to a number of criteria was used to screen two human placenta cDNA libraries in the expression vector Agtll, one randomly primed and one oligo-dT primed, by the method of Young and Davis. 23 positive clones expressing TP related antigen were isolated and plaque purified. DNA from the different clones was isolated and the TPcDNA inserts released by EcoRl digestion. The inserts could be classified into11 size classes ranging from approx. 300-1100 base pairs.The largest insert (1100 bp) was subcloned intothe plasmid vector pGEM-1. When the nick-translated plasmid (pTP4-l) was used as a probe to screen the phage clones by slot blot hybridization all the 23clones hybridized to the 1100 bp insert. A XgtllTP4 lysogen expressed B-galactosidase- TP4 fusion peptide upon IPTG induction as shown by immunobinging studied using two different antibodies to TP apoprotein: the rabbit antibody originally used to screen the libraries and an antibody raised in goat against human brain TP purified by affinity chromatography on a Factor Vll-antiVII-agarose column.Cytokines mediate many of the cellular interactions in the inflammatory and immune response systems and have a variety of actions. We have investigated the effect of rIL-1a/$,rIL-2, rlFNa/y and rTNFa on thromboplastin synthesis (TPL) in monocytes (M) and human umbilical vein endothelial cells (HUVEC). Recombinant IL- 1a and IL-16 both induced a dose dependent increase in TPL activity of monocyte (8-fold) and HUVEC cultures (15-fold) at 6h. The increase levelled off at interleukinconcentrations of 50-100u/ml. Recombinant IL-2 at 50u/ml induced a 5-fold rise in monocytes TPL. The effect of rIL-2 on HUVEC TPL synthesis at 6 h was smaller than on monocytes but still clearly significant at dose dependent. Recombinant IFN-Y (10 -10 u/ml) increased.TPL activity in HUVEC at 6h and 16 h in adose dependent manner, whereas no effect of rIFN-Y and IFN-a (1-10 u/ml) on M TPL was seen. When LPS (5pg/ml) was used to induce TPL synthesis, additional stimulation with rIFN-Y further enhanced HUVEC TPL activity, but decreased M TPL activity. Recombinant IFNa also decreased LPS induced TPL synthesis in M andhad no effect on HUVEC TPL. Recombinant TNFa (0.3x104u/ml) increased HUVEC TPL 7-fold at 6h. There wasno effect on M TPL synthesis. No endotoxin was detected in any of these preparations. CONCLUSIONS: Some biological response modifiers induced thromboplastin synthesis in monocytes (IL-ia, IL-13, IL-2) and in human umbilical vein endothelial cells (IL-ia, IL-18, IL-2, TNFa and IFNY). Some had no direct effect on TPL synthesis but inhibited the response to monocytes to other thromboplastin-inducing agents like LPS (IFNa and IFNY).

2000 ◽  
Vol 84 (10) ◽  
pp. 712-721 ◽  
Author(s):  
Kimihiko Takada ◽  
Toshiyuki Higuchi ◽  
Junichi Sugiyama ◽  
Hidemi Ishii

SummaryThis study examined the effect of verotoxin-1 (VT-1), which is released from Escherichia coli O157:H7, on endothelial expression of tissue factor (TF), a cofactor required to initiate blood coagulation. In order to elucidate the molecular basis for development of hemolytic uremic syndrome (HUS) in patients infected with E. coli O157:H7, human umbilical vein endothelial cells (HUVECs) were exposed to purified VT-1. VT-1 increased both TF activity and TF mRNA in HUVECs without loss of cell viability in a time-and dose-dependent manner from 0.1 to 10 ng/ml VT-1. Nuclear proteins extracted from VT-1-stimulated HUVECs bound to the consensus NF-κB/Rel and AP-1 binding oligonucleotides in a dose-dependent manner within 2 h after the stimulation in electrophoretic mobility shift assays (EMSA). Nuclear proteins from VT-1-stimulated HUVECs formed two complexes with the NF-κB/Rel binding motif in the human TF promoter (TF-κB motif). The supershift assays, using antibodies for human p65, p50 or c-Rel, indicated that the lower complex was composed of p65/p50 and the higher complex was a p65 homo-or hetero-dimer with the Rel family, except c-Rel. The human TF promoter contains two AP-1 binding sites, the proximal and distal AP-1 binding sites. The supershift assays indicated that AP-1 containing mainly c-Jun and JunD, positively bound to the proximal AP-1 motif of TF (TF-AP-1). The distal TF-AP-1 motif did not show positive binding with nuclear proteins from VT-1-stimulated HUVECs. Pretreatment of HUVECs with curcumin, an inhibitor of NF-κB/Rel activation, synthesis of c-Jun mRNA and binding of activated AP-1 with AP-binding oligonucleotide, prevented the VT-1 induced increase in TF mRNA and activity in VT-1-stimulated HUVECs. Curcumin also inhibited NF-κB and AP-1 binding to TF-κB and proximal TF-AP-1 oligonucleotides, respectively, in a dose-dependent manner. The present work suggests that both the NF-κB/Rel and AP-1 activated in endothelial cells by stimulation with VT-1 binds to the TF-κB and proximal AP-1 binding sites, respectively, of the TF promoter.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Zhimin Zhang ◽  
Congying Wei ◽  
Yanfen Zhou ◽  
Tao Yan ◽  
Zhengqiang Wang ◽  
...  

Homocysteine- (Hcy-) induced endothelial cell apoptosis has been suggested as a cause of Hcy-dependent vascular injury, while the proposed molecular pathways underlying this process are unclear. In this study, we investigated the adverse effects of Hcy on human umbilical vein endothelial cells (HUVEC) and the underlying mechanisms. Our results demonstrated that moderate-dose Hcy treatment induced HUVEC apoptosis in a time-dependent manner. Furthermore, prolonged Hcy treatment increased the expression of NOX4 and the production of intracellular ROS but decreased the ratio of Bcl-2/Bax and mitochondrial membrane potential (MMP), resulting in the leakage of cytochrome c and activation of caspase-3. Prolonged Hcy treatment also upregulated glucose-regulated protein 78 (GRP78), activated protein kinase RNA-like ER kinase (PERK), and induced the expression of C/EBP homologous protein (CHOP) and the phosphorylation of NF-κb. The inhibition of NOX4 decreased the production of ROS and alleviated the Hcy-induced HUVEC apoptosis and ER stress. Blocking the PERK pathway partly alleviated Hcy-induced HUVEC apoptosis and the activation of NF-κb. Taken together, our results suggest that Hcy-induced mitochondrial dysfunction crucially modulated apoptosis and contributed to the activation of ER stress in HUVEC. The excessive activation of the PERK pathway partly contributed to Hcy-induced HUVEC apoptosis and the phosphorylation of NF-κb.


Author(s):  
Vahide Askari ◽  
Somayeh Shamlou ◽  
Ali Mostafaie ◽  
Sara Khaleqi

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.


1997 ◽  
Vol 155 (3) ◽  
pp. 587-593 ◽  
Author(s):  
A Muscella ◽  
S Marsigliante ◽  
MA Carluccio ◽  
GP Vinson ◽  
C Storelli

Cultured human umbilical vein endothelial cells (HUVECs) at passage 4 specifically bound 70 +/- 12 fmol [3,5-3H]Tyr4-Ile5-angiotensin (Ang) II/mg protein, with a Kd of 0.9 +/- 0.36 nM. Binding was eliminated in cells preincubated with a monoclonal antibody (6313/G2) raised against the subtype AT1 of the Ang II receptor. Freshly seeded HUVECs were positive for 6313/G2 antibody by immunocytochemistry, and such immunoreactivity was still retained at passage 4. Incubation of HUVECs for 20 min with different concentrations of Ang II provoked a significant increment in Na+/K+ ATPase activity compared with controls, in a dose- and time-dependent manner. Maximal response was obtained with 1000 pM Ang II after 20 min stimulation and resulted in a 2.2-fold increment in Na+/K+ ATPase activity. This stimulation was abolished when cells were incubated with 1000 pM Ang II in the presence of 1 microM of the specific AT1 subtype inhibitor, DuP753. Moreover, preincubation of HUVECs with 6313/G2 or with 1 mM dithiothreitol also inhibited the stimulatory effect of Ang II. These results suggest that the AT1 receptor subtype mediates the Na+/K+ ATPase response to Ang II in these cells.


2014 ◽  
Vol 69 (7-8) ◽  
pp. 291-299 ◽  
Author(s):  
Magdalena P. Cortés ◽  
Rocío Alvarez ◽  
Evelyn Sepúlveda ◽  
Felipe Jiménez-Aspee ◽  
Luis Astudillo ◽  
...  

Recent evidence suggests that the α7 nicotinic acetylcholine receptors (α7 nAChRs) participate in the development of angiogenesis and could be a new endothelial target for revascularization in therapeutic angiogenesis. It has been shown that in human umbilical vein endothelial cells (HUVECs) α7 nAChR agonists increase the intracellular calcium concentration ([Ca2+]i), thus inducing proliferation and vessel formation which are important stages of angiogenesis. In the present study we evaluated the effect of new isoxazole compounds on the cytosolic Ca2+ signal in HUVECs using the fluorescent Ca2+ indicator Fluo-3AM and probing the involvement of α7 nAChR by means of pharmacological tools. HUVECs expressed mainly α7 nAChR, since there was no significant difference in the increase in [Ca2+]i induced by nicotine, a non-selective nicotinic agonist, in relation to choline, a selective α7 nAChR agonist. The increase in [Ca2+]i induced by 1 mM choline was inhibited significantly (p = 0.014) in cells which had been pre-incubated for 15 min with methyllycaconitine (MLA), a selective α7 nAChR antagonist. The studied compounds 1, 2, and 3 induced an increase in [Ca2+]i in a dose-dependent manner. Compound 1 at 10 mM induced a greater increase in [Ca2+]i than compounds 2 and 3. The increase in [Ca2+]i induced by compound 1 was significantly inhibited by MLA (p = 0.013) and completely inhibited by mecamylamine, a non-selective nAChR antagonist, indicating that the isoxazolic compound 1 acts as an α7 nAChR agonist.


2001 ◽  
Vol 357 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Marc A. LAFLEUR ◽  
Morley D. HOLLENBERG ◽  
Susan J. ATKINSON ◽  
Vera KNÄUPER ◽  
Gillian MURPHY ◽  
...  

Thrombin, a critical enzyme in the coagulation cascade, has also been associated with angiogenesis and activation of the zymogen form of matrix metalloproteinase-2 (MMP-2 or gelatinase-A). We show that thrombin activated pro-MMP-2 in a dose- and time-dependent manner in cultured human umbilical-vein endothelial cells (HUVECs) to generate a catalytically active 63kDa protein that accumulated as the predominant form in the conditioned medium. This 63kDa thrombin-activated MMP-2 is distinct from the 62kDa species found following concanavalin A or PMA stimulated pro-MMP-2 activation. Hirudin and leupeptin blocked thrombin-induced pro-MMP-2 activation, demonstrating that the proteolytic activity of thrombin is essential. However, activation was also dependent upon membrane-type-MMP (MT-MMP) action, since it was blocked by EDTA, o-phenanthroline, hydroxamate metalloproteinase inhibitors, tissue inhibitor of metalloproteinase-2 (TIMP-2) and TIMP-4, but not TIMP-1. Thrombin inefficiently cleaved recombinant 72kDa pro-MMP-2, but efficiently cleaved the 64kDa MT-MMP-processed intermediate form in the presence of cells. Thrombin also rapidly (within 1h) increased cellular MT-MMP activity, and at longer time points (>6h) it increased expression of MT1-MMP mRNA and protein. Thus signalling via proteinase-activated receptors (PARs) may play a role in thrombin-induced MMP-2 activation, though this does not appear to involve PAR1, PAR2, or PAR4 in HUVECs. These results indicate that in HUVECs the activation of pro-MMP-2 by thrombin involves increased MT-MMP activity and preferential cleavage of the MT-MMP-processed 64kDa MMP-2 form in the presence of cells. The integration of these proteinase systems in the vascular endothelium may be important during thrombogenesis and tissue remodelling associated with neovascularization.


2013 ◽  
Vol 641-642 ◽  
pp. 744-747
Author(s):  
Shu Jing Wang ◽  
Fei Wang ◽  
Jia Liu ◽  
Shan Jiang ◽  
Ning Chen ◽  
...  

The direct anti-tumor T-7 peptide of tumstatin was obtained to study its effect on human hepatoma cells (HepG-2) and human umbilical vein endothelial cells (ECV304). T-7 peptide was synthesized and its purity was up to 98.5%. MTT assay, growth curve, transmission electron microscopy(TEM) were used to detect the proliferation inhibition and pro-apoptotic function. MTT experiments and growth curve experiments showed that the survival of human hepatoma cells (HepG-2) decreased in a time- and dose-dependent way with the concentration of T-7 peptide increased. T-7 peptide can induce apoptosis of HepG-2 significantly. Apoptosis features were observed by TEM. However, the inhibition of T-7 peptide on human umbilical vein endothelial cells (ECV304) was weaker. Experiments showed thatT-7 peptide can affect HepG-2 cells. It had a certain therapeutic effect on human hepatocellular carcinoma. T-7 peptide have little effect on ECV304 cells, which means it didn’t influence the formation of tumor angiogenesis and normal cells


2016 ◽  
Vol 71 (1-2) ◽  
pp. 21-28 ◽  
Author(s):  
Mi Hwa Park ◽  
Jae-Won Ju ◽  
Mihyang Kim ◽  
Ji-Sook Han

AbstractEndothelial cell dysfunction is considered a major cause of vascular complications in diabetes. In the present study, we investigated the protective effect of daidzein, a natural isoflavonoid, against high-glucose–induced oxidative damage in human umbilical vein endothelial cells (HUVECs). Treatment with a high concentration of glucose (30 mM) induced oxidative stress in the endothelial cells, against which daidzein protected the cells as demonstrated by significantly increased cell viability. In addition, lipid peroxidation, intracellular reactive oxygen species (ROS) generation, and indirect nitric oxide levels induced by the high glucose treatment were significantly reduced in the presence of daidzein (0.02–0.1 mM) in a dose-dependent manner. High glucose levels induced the overexpression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB proteins in HUVECs, which was suppressed by treatment with 0.04 mM daidzein. These findings indicate the potential of daidzein to reduce high glucose-induced oxidative stress.


2008 ◽  
Vol 295 (3) ◽  
pp. H1177-H1181 ◽  
Author(s):  
R. W. S. Li ◽  
Ricky Y. K. Man ◽  
Paul M. Vanhoutte ◽  
George P. H. Leung

The involvement of ecto-5′-nucleotidase (E-5′Nu) in the elevation of extracellular adenosine during inflammation is unclear. In the present study, the effect of lipopolysaccharide (LPS), an inflammation inducer, was investigated on E-5′Nu in human umbilical vein endothelial cells (HUVECs). E-5′Nu activity was enhanced after a 24 h exposure to LPS. This effect was dose dependent, with an EC50 of 1.66 ng/ml. At 10 μM, the phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002 abolished the LPS-induced E-5′Nu activity. However, at 10 μM, the NF-κB inhibitor ammonium pyrrolidine dithiocarbamate had no effect. LPS upregulated the protein expression but not the messenger RNA expression of E-5′Nu. The inhibition of E-5′Nu by 100 μM α,β-methylene adenosine-5′-diphosphate increased the LPS-induced inflammation, suggesting that E-5′Nu plays a significant role in reducing inflammation, probably through the generation of adenosine. In conclusion, the experiments indicate that LPS upregulates E-5′Nu activity in HUVECs through a PI3K-dependent increase in the abundance of E-5′Nu on cell membranes. Since adenosine is an anti-inflammatory molecule, E-5′Nu upregulation may be crucial in protecting endothelial cells against inflammatory damage.


2017 ◽  
Vol 41 (4) ◽  
pp. 1346-1359 ◽  
Author(s):  
Li Ju ◽  
Zhiwen Zhou ◽  
Bo Jiang ◽  
Yue Lou ◽  
Xirong Guo

Background/Aims: Pro-angiogenic factors VEGF and IL-8 play a major role in modulating the migratory potential of endothelial cells. The goal of this study was to investigate the effect of autocrine VEGF and IL-8 in the form of self-conditioned medium (CM) on human umbilical vein endothelial cells (HUVECs). Methods: Enzyme-linked immunosorbent assay (ELISA) examined the automatic secretion of VEGF and IL-8 protein by HUVECs. Western blot, small interfering RNA (siRNA), pulldown and Transwell assays were used to explore the role and the mechanism of autocrine VEGF and IL-8 in migration of HUVECs. Results: Neutralizing VEGF and IL-8 in CM significantly abrogated CM-induced migration of HUVECs. Autocrine VEGF and IL-8 increased Src phosphorylation, Rac1 activity and PAK1 phosphorylation in a time dependent manner. Additionally, blocking Rac1 activity with Rac1 siRNA largely abolished autocrine VEGF and IL-8-induced cell migration. Vav2 siRNA suppressed autocrine VEGF and IL-8-induced Rac1 activation and cell migration. Furthermore, blocking Src signaling with PP2, a specific inhibitor for Src, markedly prevented autocrine VEGF and IL-8-induced Vav2 and Rac1 activation as well as consequently cell migration. PAK1 siRNA also significantly abolished autocrine VEGF and IL-8-induced cell migration. Conclusions: We demonstrated for the first time that autocrine VEGF and IL-8 promoted endothelial cell migration via the Src/Vav2/Rac1/PAK1 signaling pathway. This finding reveals the molecular mechanism in the increase of endothelial cell migration induced by autocrine growth factors and cytokines, which is expected to provide a novel therapeutic target in vascular diseases.


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