Estrogen modulates paracellular permeability of human endothelial cells by eNOS- and iNOS-related mechanisms

1999 ◽  
Vol 276 (2) ◽  
pp. C337-C349 ◽  
Author(s):  
Michael M. Cho ◽  
Nicholas P. Ziats ◽  
Dipika Pal ◽  
Wulf H. Utian ◽  
George I. Gorodeski

Estradiol had a biphasic effect on permeability across cultures of human umbilical vein endothelial cells (HUVEC): at nanomolar concentrations it decreased the HUVEC culture permeability, but at micromolar concentrations it increased the permeability. The objective of the present study was to test the hypothesis that the changes in permeability were mediated by nitric oxide (NO)-related mechanisms. The results revealed dual modulation of endothelial paracellular permeability by estrogen. 1) An endothelial NO synthase (eNOS)-, NO-, and cGMP-related, Ca2+-dependent decrease in permeability was activated by nanomolar concentrations of estradiol, resulting in enhanced Cl−influx, increased cell size, and increases in the resistance of the lateral intercellular space ( RLIS) and in the resistance of the tight junctions ( RTJ); these effects appeared to be limited by the ability of cells to generate cGMP in response to NO. 2) An inducible NO synthase (iNOS)- and NO-related, Ca2+-independent increase in permeability was activated by micromolar concentrations of estradiol, resulting in enhanced Cl−efflux, decreased cell size, and decreased RLISand RTJ. We conclude that the net effect on transendothelial permeability across HUVEC depends on the relative contributions of each of these two systems to the total paracellular resistance.

1989 ◽  
Vol 62 (02) ◽  
pp. 699-703 ◽  
Author(s):  
Rob J Aerts ◽  
Karin Gillis ◽  
Hans Pannekoek

SummaryIt has recently been shown that the fibrinolytic components plasminogen and tissue-type plasminogen activator (t-PA) both bind to cultured human umbilical vein endothelial cells (HUVEC). After cleavage of t-PA by plasmin, “single-chain” t-PA (sct-PA) is converted into “two-chain” t-PA (tct-PA), which differs from the former in a number of respects. We compared binding of sct-PA and tct-PA to the surface of HUVEC. Removal of t-PA bound to HUVEC by a mild treatment with acid and a subsequent quantification of eluted t-PA both by activity- and immunoradiometric assays revealed that, at concentrations between 10 and 500 nM, HUVEC bind about 3-4 times more sct-PA than tct-PA. At these concentrations, both sct-PA and tct-PA remain active when bound to HUVEC. Mutual competition experiments showed that sct-PA and tct-PA can virtually fully inhibit binding of each other to HUVEC, but that an about twofold higher concentration of tct-PA is required to prevent halfmaximal binding of sct-PA than visa versa. These results demonstrate that sct-PA and tct-PA bind with different affinities to the same binding sites on HUVEC.


1995 ◽  
Vol 74 (02) ◽  
pp. 698-703 ◽  
Author(s):  
Catherine Lenich ◽  
Ralph Pannell ◽  
Victor Gurewich

SummaryFactor XII has long been implicated in the intrinsic pathway of fibrinolysis, but the mechanism by which it triggers plasminogen activation and targets fibrinolysis has not been established. In the present study, the assembly and function of activated Factor XII (F.XIIa), prourokinase (pro-u-PA), high molecular weight kininogen (H-kininogen), and prekallikrein on human umbilical vein endothelial cells (HUVEC) was investigated. 125I-prekallikrein was shown to bind to HUVEC via receptor-bound H-kininogen in the presence of 50 μM ZnCl2. After the addition of F.XIIa, 78% of the 125I-prekallikrein initially bound to HUVEC was converted to 125I-kallikrein. However, only 6% of the HUVEC-bound 125I-pro-u-PA was thereby activated. This discrepancy was shown to be related to rapid dissociation (>50% within 15 min) of prekallikrein/kallikrein, but not pro-u-PA, from HUVEC. Increasing the level of cell-bound kallikrein increased the portion of cell-bound pro-u-PA activated, indicating that their co-localization was important for this pathway. Finally, F.XIIa was shown to trigger plasminogen activation on HUVEC via this pathway. This assembly of reactants on the endothelium suggests a mechanism whereby local fibrinolysis may be triggered by blood coagulation.


1983 ◽  
Vol 49 (02) ◽  
pp. 069-072 ◽  
Author(s):  
U L H Johnsen ◽  
T Lyberg ◽  
K S Galdal ◽  
H Prydz

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.


1986 ◽  
Vol 6 (8) ◽  
pp. 3018-3022
Author(s):  
B D Tong ◽  
S E Levine ◽  
M Jaye ◽  
G Ricca ◽  
W Drohan ◽  
...  

A clone containing the 3' end of the mRNA for the human c-sis gene (homologous to the B chain of platelet-derived growth factor) was isolated from a cDNA library derived from human umbilical vein endothelial cells and then sequenced. The analysis of possible translation products in all three reading frames indicated that the A chain of platelet-derived growth factor was not coded for within the 3' end of the c-sis mRNA. The 3' end of the mRNA for c-sis is contained in or adjacent to exon 6.


2004 ◽  
Vol 164 (6) ◽  
pp. 811-817 ◽  
Author(s):  
Carlo Iomini ◽  
Karla Tejada ◽  
Wenjun Mo ◽  
Heikki Vaananen ◽  
Gianni Piperno

We identified primary cilia and centrosomes in cultured human umbilical vein endothelial cells (HUVEC) by antibodies to acetyl-α-tubulin and capillary morphogenesis gene-1 product (CMG-1), a human homologue of the intraflagellar transport (IFT) protein IFT-71 in Chlamydomonas. CMG-1 was present in particles along primary cilia of HUVEC at interphase and around the oldest basal body/centriole at interphase and mitosis. To study the response of primary cilia and centrosomes to mechanical stimuli, we exposed cultured HUVEC to laminar shear stress (LSS). Under LSS, all primary cilia disassembled, and centrosomes were deprived of CMG-1. We conclude that the exposure to LSS ends the IFT in cultured endothelial cells.


1988 ◽  
Vol 65 (3) ◽  
pp. 1372-1376 ◽  
Author(s):  
P. D. Thomas ◽  
F. W. Hampson ◽  
G. W. Hunninghake

The adult respiratory distress syndrome (ARDS) is frequently caused by exposure of the lung endothelium to circulating endotoxin (lipopolysaccharide, LPS) and pulmonary infections frequently develop during the course of ARDS. The present studies demonstrate that LPS and interleukin 1 (IL-1, a mediator released by endothelial cells after exposure to LPS) enhance the adherence of Staphylococcus aureus to human umbilical vein endothelial cells. gamma-Interferon, another mediator that induces expression of some cell surface antigens on endothelial cells, had no effect on bacterial adherence. The adherence of bacteria to endothelium was increased by prior opsonization of the bacteria with fresh human serum and was reduced by prior absorption of the serum with bacteria before the use of the serum for opsonization. The capacity of LPS to increase bacterial adherence was time dependent and was maximally expressed after 6 h of exposure; it was blocked by exposure of endothelial cells to LPS in the presence of reduced temperature or dactinomycin (Actinomycin D). These observations suggest that circulating LPS not only can trigger the development of ARDS but also may predispose the lung to the development of pulmonary infections by increasing adherence of bacteria to endothelium.


1988 ◽  
Vol 255 (1) ◽  
pp. 179-184 ◽  
Author(s):  
T J Hallam ◽  
R Jacob ◽  
J E Merritt

Human umbilical-vein endothelial cells stimulated with thrombin or histamine show an increase in [Ca2+]i (cytoplasmic free calcium concn.) that is maintained well above the basal pre-stimulated value as long as agonist and a source of extracellular Ca2+ are present. These results provide circumstantial evidence that agonists stimulate influx of Ca2+ across the plasma membrane and into the cytoplasm. Here, we have used Mn2+ as the extracellular bivalent cation which can bind to the fluorescent Ca2+ indicator fura-2 to quench its fluorescence completely. Human umbilical-vein endothelial cells were loaded with fura-2 and, in the presence of extracellular Mn2+, thrombin and histamine were shown to cause quenching of the intracellular dye. This result demonstrates conclusively that agonists can stimulate the influx of bivalent cations. Stimulated discharge of Ca2+ from intracellular stores and influx of Mn2+ were temporally resolved in the same cells to show that release of Ca2+ from intracellular stores clearly precedes influx. Influx of Mn2+ was also demonstrated when extracellular Mn2+ was added after agonist at a time when [Ca2+]i had fallen back to the basal value, showing that influx is not dependent on elevated [Ca2+]i.


2013 ◽  
Vol 114 (2) ◽  
pp. 274-285 ◽  
Author(s):  
Hsiu-Chung Ou ◽  
Yueh-Ling Hsieh ◽  
Nae-Cherng Yang ◽  
Kun-Ling Tsai ◽  
Kai-Ling Chen ◽  
...  

Atherosclerosis is a complex inflammatory arterial disease, and oxidized low-density lipoprotein (oxLDL) is directly associated with chronic vascular inflammation. Previous studies have shown that Ginkgo biloba extract (GbE) acts as a therapeutic agent for neurological and cardiovascular disorders. However, the mechanisms mediating the actions of GbE are still largely unknown. In the present study, we tested the hypothesis that GbE protects against oxLDL-induced endothelial dysfunction via an AMP-activated protein kinase (AMPK)-dependent mechanism. Human umbilical vein endothelial cells were treated with GbE, followed by oxLDL, for indicated time periods. Results from Western blot showed that GbE inhibited the membrane translocation of the NADPH oxidase subunits p47phox and Rac-1 and attenuated the increase in protein expression of membrane subunits gp91 and p22phox caused by oxLDL-induced AMPK dephosphorylation and subsequent PKC activation. AMPK-α1-specific small interfering RNA-transfected cells that had been exposed to GbE followed by oxLDL revealed elevated levels of PKC and p47phox. In addition, exposure to oxLDL resulted in reduced AMPK-mediated Akt/endothelial nitric oxide (NO) synthase signaling and the induction of phosphorylation of p38 mitogen-activated protein kinase, which, in turn, activated NF-κB-mediated inflammatory responses, such as the release of interleukin-8, the expression of the adhesion molecule, and the adherence of monocytic cells to human umbilical vein endothelial cells. Furthermore, oxLDL upregulated the expression of inducible NO synthase, thereby augmenting the formation of NO and protein nitrosylation. Pretreatment with GbE, however, exerted significant cytoprotective effects in a dose-dependent manner. Results from this study may provide insight into a possible molecular mechanism by which GbE protects against oxLDL-induced endothelial dysfunction.


1996 ◽  
Vol 315 (1) ◽  
pp. 281-287 ◽  
Author(s):  
Gudrun MANCUSI ◽  
Caroline HUTTER ◽  
Sabina BAUMGARTNER-PARZER ◽  
Kurt SCHMIDT ◽  
Wolfgang SCHÜTZ ◽  
...  

Alterations in G-protein-controlled signalling pathways (primarily pathways controlled by Gs and Gi) have been reported to occur in animal models of diabetes mellitus. We have therefore studied the effect of a long-term exposure of human umbilical vein endothelial cells to elevated concentrations of glucose on expression and function of G-protein subunits and endothelial NO synthase. Long-term incubation in high glucose (30 mM for 15 days) did not affect the levels of Giα-2, Gqα, the splice variants (long and short form) of Gsα, and the G-protein β-subunits or adenylate cyclase activity: basal, as well as isoprenaline-, forskolin- and guanosine 5´-[γ-thio]triphosphate-stimulated enzyme activities were comparable in high- and low-glucose-treated cells, thus ruling out any functional changes in the stimulatory pathway. Pretreatment of endothelial cells with pertussis toxin blocked a substantial fraction (50%) of the mitogenic response to serum factor(s) which depend(s) on functional Gi2. The sensitivity of cells cultured in high glucose was comparable with that of the paired controls maintained in normal glucose (EC50 = 3.1±0.5 and 3.3±0.4 ng/ml respectively). Similarly, we failed to detect any differences in endothelial NO synthase expression, or intracellular distribution and basal activity of the enzyme in endothelial cells cultured in high glucose. Stimulation of NO synthase in intact cells revealed a comparable response to the calcium ionophore (A23187). In contrast, stimulation with histamine (which acts via H1-receptors predominantly coupled to Gq) resulted in a significantly increased response in the cells maintained in high glucose. These data are suggestive of an altered H1-histamine receptor–Gq–phospholipase C pathway in endothelial cells cultured in high glucose concentrations, but rule out any glucose-induced functional changes in Gs- and Gi-controlled signalling pathways.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Chengcheng Chang ◽  
Hongli Liu ◽  
Cong Wei ◽  
Liping Chang ◽  
Junqing Liang ◽  
...  

Vascular hyperpermeability resulting from distortion of endothelial junctions is associated with a number of cardiovascular diseases. Endothelial tight junction regulates the paracellular permeability of macromolecules, a function ofHuman Umbilical Vein Endothelial Cells(HUVEC) monolayers that can be regulated byoxidized Low-density Lipoprotein(ox-LDL). However, the understanding of drug regulation of vascular hyperpermeability is so far limited. This study thus aimed to investigate the role ofTongxinluo(TXL) in the maintenance of the vascular endothelial paracellular permeability. Here, changes in permeability were determined by measuring the paracellular flux of FITC-dextran 40000 (FD40), while protein expression and intercellular distribution were examined by western blot and immunofluorescence assay, respectively. We found that TXL alleviated the ox-LDL-induced increase in flux of FD40 and then reduced the hyperpermeability. Moreover, ox-LDL-induced disruptions of ZO-1, occludin, and claudin1 were also restored. This is via the activation of ERK1/2 in the vascular endothelial cells. Our results provide insights into the molecular mechanism by which TXL alleviates ox-LDL-induced hyperpermeability and provide the basis for further investigations of TXL as regulators of vascular barrier function.


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