Abstract 1432: Nitric Oxide Bioavailability is Lower in Endothelium of Healthy Mexican American Donors as Compared to Non-Hispanic White Donors: Effect of Nebivolol

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
R. P Mason ◽  
Ruslan Kubant ◽  
Christopher Malinski ◽  
Adam Jacoby ◽  
Robert F Jacob ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Function ◽  
Mexican Americans ◽  
Mexican American ◽  
Umbilical Vein ◽  
Coupling Efficiency ◽  
Calcium Ionophore ◽  
Stress Factors ◽  
No Bioavailability

Background: Epidemiologic studies indicate that Mexican Americans (MA) have a higher prevalence of CV risk factors and disease as compared with non-Hispanic whites (NHW). This increase in CV risk may be due, in part, to differences in endothelial function. In this study, we measured endothelial function in cells from normotensive, age-matched MA and NHW donors, as well as the effects of treatment with nebivolol, a new β 1 -selective blocker with vasodilating properties. Methods: Endothelial nitric oxide (NO) and peroxynitrite (ONOO − ) release in human umbilical vein endothelial cells (HUVECs) from age-matched MA and NHW donors were measured simultaneously using a nanosensor array. The effects of nebivolol on NO and ONOO − release were evaluated following pretreatment (24 h) with a calcium ionophore (CaI) as a receptor-independent stimulus. Endothelial NO synthase (eNOS) levels were measured by Western blot analysis, and drug-membrane interactions were determined by small angle x-ray diffraction approaches. Results: NO bioavailability in endothelial cells of MA donors was 30% lower than that of cells from NHW donors (383 ± 10 nM versus 543 ± 8 nM, n=6) following stimulation with CaI (1.0 μM). Pretreatment with nebivolol (1.0 μM) eliminated these interracial differences and enhanced NO release disproportionately in MA cells (57%) versus NHW cells (20%). Nebivolol also reduced ONOO − levels in MA endothelium by 75% (746 ± 12 nM to 195 ± 10 nM) and by 50% in NHW cells (416 ± 7 nM to 191 ± 13 nM). The ratio of NO to ONOO − , an indicator of eNOS coupling, increased more than 5-fold in MA cells following nebivolol treatment. In addition, eNOS levels were 40% lower in MA endothelium compared to NHW, but increased 2-fold with nebivolol treatment. These effects were not observed with atenolol, a hydrophilic β 1 -selective antagonist. Conclusion: We observed differences between Mexican Americans and non-Hispanic whites in endothelial NO bioavailability and nitroxidative stress–factors that may contribute to increased CV risk. Treatment with nebivolol, but not atenolol, enhanced both the expression and coupling efficiency of eNOS in Mexican American endothelium.

scholarly journals Omega-3 fatty acids differentially alter the expression of detoxification enzymes and nitric oxide bioavailability in endothelial cells during IL-6 exposure

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S C R Sherratt ◽  
P Libby ◽  
D L Bhatt ◽  
H Dawoud ◽  
T Malinski ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Umbilical Vein ◽  
Calcium Ionophore ◽  
Detoxification Enzymes ◽  
Omega 3 ◽  
Private Company ◽  
Sod Isoforms ◽  
No Bioavailability

Abstract Background Atherosclerotic plaques can elaborate reactive oxygen species (ROS) that reduce nitric oxide (NO) bioavailability. Cellular detoxification enzymes including various peroxiredoxin (PRDX) and superoxide dismutase (SOD) isoforms can inactivate ROS. The omega-3 fatty acid (n3-FA) eicosapentaenoic acid (EPA) reduced cardiovascular (CV) events in high-risk patients (REDUCE-IT), a benefit not observed with mixed n3-FAs containing docosahexaenoic acid (DHA). Purpose The purpose of this study was to compare the effects of EPA and DHA on NO bioavailability and expression of detoxification enzymes in the vascular endothelium in vitro. Methods Human umbilical vein endothelial cells (HUVECs) were pretreated with EPA or DHA at equimolar levels (10 μM) for 2 h, then challenged with IL-6 at 12 ng/ml for 24 h. Proteomic analysis was performed using LC/MS to measure relative protein expression. Only significant (p<0.05) changes between treatment groups >1-fold were analyzed. Cells were stimulated with calcium ionophore to measure NO and peroxynitrite (ONOO-) release using a porphyrinic nanosensor. Results EPA, but not DHA, augmented PRDX-2 and SOD1 expression in HUVECs relative to IL-6 alone (1.2-fold and 1.6-fold, respectively, p=0.03). EPA also significantly lowered other isoforms unlike DHA. Either EPA or DHA increased thioredoxin expression by 1.5-fold (p=0.001) and 1.3-fold (p=0.02), respectively and decreased SOD2 expression by 1.5-fold (p=8.75E-11) and 1.6-fold (p=6.03E-9), respectively. IL-6 alone only increased expression of 6 detoxification enzymes by at least 1.2-fold, relative to vehicle. Unlike DHA, EPA also increased the NO to ONOO- release ratio by 36% (p<0.05) relative to IL-6 alone, without changes in NO synthase (eNOS) expression. Conclusions n3-FAs differentially influenced NO bioavailability and expression of ROS detoxification proteins, including peroxiredoxin and SOD isoforms. The net benefits of EPA on eNOS function and ROS detoxification may contribute to reduced atherothrombotic risk compared to DHA. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Amarin Pharma Inc., Elucida Research

Nitric oxide synthesis is impaired in glutathione-depleted human umbilical vein endothelial cells

1993 ◽  
Vol 265 (3) ◽  
pp. C728-C732 ◽  
Author(s):  
D. Ghigo ◽  
P. Alessio ◽  
A. Foco ◽  
F. Bussolino ◽  
C. Costamagna ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Reduced Glutathione ◽  
Umbilical Vein ◽  
Calcium Ionophore ◽  
Human Endothelial Cells ◽  
Cgmp Production ◽  
Endothelium Derived Relaxing Factor ◽  
Citrulline Synthesis ◽  
Umbilical Vein Endothelial Cells

Human endothelial cells cultured from umbilical vein (HUVEC) were tested for their ability to synthesize nitric oxide (NO), which has been identified as an endothelium-derived relaxing factor. The synthesis of this free radical (detected as citrulline, which is produced stoichiometrically with NO from arginine) in HUVEC is Ca2+ dependent, is increased sevenfold by the calcium ionophore ionomycin, and accounts for most basal and ionomycin-induced guanosine 3',5'-cyclic monophosphate (cGMP) production. Loading of cells with reduced glutathione (GSH), but not with N-(2-mercaptopropionyl)- glycine (MPG), led to increased citrulline production, both basally and after ionomycin stimulation. When the cells were depleted of GSH by incubation with 1-chloro-2,4-dinitrobenzene (CDNB), citrulline synthesis and cGMP production were inhibited in a concentration-dependent way. CDNB was not cytotoxic and did not inhibit cGMP increase elicited by sodium nitroprusside; cell loading with GSH (but not with MPG) relieved the block of citrulline synthesis. These results suggest that GSH is necessary in HUVEC for NO synthesis rather than for the NO effect on guanylate cyclase.

scholarly journals VLDL Induced Modulation of Nitric Oxide Signalling and Cell Redox Homeostasis in HUVEC

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Maria Chiara Magnifico ◽  
Roxana Elena Oberkersch ◽  
Azzurra Mollo ◽  
Luca Giambelli ◽  
Yasmine Grooten ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Umbilical Vein ◽  
Redox Homeostasis ◽  
No Synthase ◽  
Very Low Density Lipoproteins ◽  
Enos Uncoupling ◽  
Phosphorylation Pattern ◽  
No Bioavailability ◽  
Umbilical Vein Endothelial Cells

High levels of circulating lipoprotein constitute a risk factor for cardiovascular diseases, and in this context, the specific role of the very-low-density lipoproteins (VLDL) is poorly understood. The response of human umbilical vein endothelial cells (HUVEC) to VLDL exposure was studied, especially focusing on the pathways involved in alteration of redox homeostasis and nitric oxide (NO) bioavailability. The results obtained by the analysis of the expression level of genes implicated in the NO metabolism and oxidative stress response indicated a strong activation of inducible NO synthase (iNOS) upon 24 h exposure to VLDL, particularly if these have been preventively oxidised. Simultaneously, both mRNA and protein expression of endothelial NO synthase (eNOS) were decreased and its phosphorylation pattern, at the key residues Tyr495 and Ser1177, strongly suggested the occurrence of the eNOS uncoupling. The results are consistent with the observed increased production of nitrites and nitrates (NOx), reactive oxygen species (ROS), 3-nitrotyrosine (3-NT), and, at mitochondrial level, a deficit in mitochondrial O2consumption. Altogether, these data suggest that the VLDL, particularly if oxidised, when allowed to persist in contact with endothelial cells, strongly alter NO bioavailability, affecting redox homeostasis and mitochondrial function.

scholarly journals The Effect of Race and Shear Stress on CRP-Induced Responses in Endothelial Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chenyi Ling ◽  
Marc D. Cook ◽  
Heather Grimm ◽  
Maitha Aldokhayyil ◽  
Dulce Gomez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Function ◽  
Racial Differences ◽  
Umbilical Vein ◽  
Receptor Expression ◽  
No Production ◽  
Laminar Shear Stress ◽  
Enos Expression

Background. C-reactive protein (CRP) is an independent biomarker of systemic inflammation and a predictor of future cardiovascular disease (CVD). More than just a pure bystander, CRP directly interacts with endothelial cells to decrease endothelial nitric oxide synthase (eNOS) expression and bioactivity, decrease nitric oxide (NO) production, and increase the release of vasoconstrictors and adhesion molecules. Race is significantly associated with CRP levels and CVD risks. With aerobic exercise, the vessel wall is exposed to chronic high laminar shear stress (HiLSS) that shifts the endothelium phenotype towards an anti-inflammatory, antioxidant, antiapoptotic, and antiproliferative environment. Thus, the purpose of this study was to assess the racial differences concerning the CRP-induced effects in endothelial cells and the potential role of HiLSS in mitigating these differences. Methods. Human umbilical vein endothelial cells (HUVECs) from four African American (AA) and four Caucasian (CA) donors were cultured and incubated under the following conditions: (1) static control, (2) CRP (10 μg/mL, 24 hours), (3) CRP receptor (FcγRIIB) inhibitor followed by CRP stimulation, (4) HiLSS (20 dyne/cm2, 24 hours), and (5) HiLSS followed by CRP stimulation. Results. AA HUVECs had significantly higher FcγRIIB receptor expression under both basal and CRP incubation conditions. Blocking FcγRIIB receptor significantly attenuated the CRP-induced decrements in eNOS expression only in AA HUVECs. Finally, HiLSS significantly counteracted CRP-induced effects. Conclusion. Understanding potential racial differences in endothelial function is important to improve CVD prevention. Our results shed light on FcγRIIB receptor as a potential contributor to racial differences in endothelial function in AA.

Inhibition of tetrahydrobiopterin biosynthesis impairs endothelium-dependent relaxations in canine basilar artery

1997 ◽  
Vol 273 (2) ◽  
pp. H718-H724 ◽  
Author(s):  
H. Kinoshita ◽  
S. Milstien ◽  
C. Wambi ◽  
Z. S. Katusic
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Nitric Oxide Synthase ◽  
Endothelial Function ◽  
Isometric Force ◽  
Cerebral Arteries ◽  
Calcium Ionophore ◽  
Nitric Oxide Donor ◽  
Ionophore A23187 ◽  
Oxide Synthase

Tetrahydrobiopterin is an essential cofactor in biosynthesis of nitric oxide. The present study was designed to determine the effect of decreased intracellular tetrahydrobiopterin levels on endothelial function of isolated cerebral arteries. Blood vessels were incubated for 6 h in minimum essential medium (MEM) in the presence or absence of a GTP cyclohydrolase I inhibitor, 2,4-diamino-6-hydroxypyrimidine (DAHP, 10(-2) M). Rings with and without endothelium were suspended for isometric force recording in the presence of a cyclooxygenase inhibitor, indomethacin (10(-5) M). In arteries with endothelium, DAHP significantly reduced intracellular levels of tetrahydrobiopterin. DAHP in combination with a precursor of the salvage pathway of tetrahydrobiopterin biosynthesis, sepiapterin (10(-4) M), not only restored but increased levels of tetrahydrobiopterin above control values. In DAHP-treated arteries, endothelium-dependent relaxations to bradykinin (10(-10)-10(-6) M) or calcium ionophore A23187 (10(-9)-10(-6) M) were significantly reduced, whereas endothelium-independent relaxations to a nitric oxide donor, 3-morpholinosydnonimine (10(-9)-10(-4) M), were not affected. When DAHP-treated arteries with endothelium were incubated with sepiapterin (10(-4) M) or superoxide dismutase (150 U/ml), relaxations to bradykinin and A23187 were restored to control levels. In contrast, superoxide dismutase did not affect endothelium-dependent relaxations in arteries incubated in MEM. A nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (10(-4) M), abolished relaxations to bradykinin or A23187 in control arteries and in DAHP-treated arteries. These studies demonstrate that in cerebral arteries, decreased intracellular levels of tetrahydrobiopterin can reduce endothelium-dependent relaxations. Production of superoxide anions during activation of dysfunctional endothelial nitric oxide synthase appears to be responsible for the impairment of endothelial function.

Hypoxia-induced pulmonary endothelin-1 expression is unaltered by nitric oxide

2002 ◽  
Vol 92 (3) ◽  
pp. 1152-1158 ◽  
Author(s):  
Scott Earley ◽  
Leif D. Nelin ◽  
Louis G. Chicoine ◽  
Benjimen R. Walker
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Promoter Activity ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Exposure ◽  
Mrna Levels ◽  
Protective Effects ◽  
No Donor ◽  
Umbilical Vein Endothelial Cells

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O2) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso- N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O2) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O2) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O2) exposure. ET-1 promoter activity after S-nitroso- N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.

Effects of homocysteine on endothelial nitric oxide production

2000 ◽  
Vol 279 (4) ◽  
pp. F671-F678 ◽  
Author(s):  
Xiaohui Zhang ◽  
Hong Li ◽  
Haoli Jin ◽  
Zachary Ebin ◽  
Sergey Brodsky ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Redox State ◽  
Calcium Ionophore ◽  
No Production ◽  
Cellular Redox ◽  
A Cell ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Peroxynitrite Scavengers

Hyperhomocysteinemia (HHCy) is an independent and graded cardiovascular risk factor. HHCy is prevalent in patients with chronic renal failure, contributing to the increased mortality rate. Controversy exists as to the effects of HHCy on nitric oxide (NO) production: it has been shown that HHCy both increases and suppresses it. We addressed this problem by using amperometric electrochemical NO detection with a porphyrinic microelectrode to study responses of endothelial cells incubated with homocysteine (Hcy) to the stimulation with bradykinin, calcium ionophore, or l-arginine. Twenty-four-hour preincubation with Hcy (10, 20, and 50 μM) resulted in a gradual decline in responsiveness of endothelial cells to the above stimuli. Hcy did not affect the expression of endothelial nitric oxide synthase (eNOS), but it stimulated formation of superoxide anions, as judged by fluorescence of dichlorofluorescein, and peroxynitrite, as detected by using immunoprecipitation and immunoblotting of proteins modified by tyrosine nitration. Hcy did not directly affect the ability of recombinant eNOS to generate NO, but oxidation of sulfhydryl groups in eNOS reduced its NO-generating activity. Addition of 5-methyltetrahydrofolate restored NO responses to all agonists tested but affected neither the expression of the enzyme nor formation of nitrotyrosine-modified proteins. In addition, a scavenger of peroxynitrite or a cell-permeant superoxide dismutase mimetic reversed the Hcy-induced suppression of NO production by endothelial cells. In conclusion, electrochemical detection of NO release from cultured endothelial cells demonstrated that concentrations of Hcy >20 μM produce a significant indirect suppression of eNOS activity without any discernible effects on its expression. Folates, superoxide ions, and peroxynitrite scavengers restore the NO-generating activity to eNOS, collectively suggesting that cellular redox state plays an important role in HCy-suppressed NO-generating function of this enzyme.

scholarly journals Alpha-Asarone Protects Endothelial Cells from Injury by Angiotensin II

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hai-Xia Shi ◽  
Jiajun Yang ◽  
Tao Yang ◽  
Yong-Liang Xue ◽  
Jun Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Cell Injury ◽  
Fluorescent Dyes ◽  
Umbilical Vein ◽  
Protective Effects ◽  
Ang Ii ◽  
Versus Model

α-Asarone is the major therapeutical constituent ofAcorus tatarinowiiSchott. In this study, the potential protective effects ofα-asarone against endothelial cell injury induced by angiotensin II were investigatedin vitro. The EA.hy926 cell line derived from human umbilical vein endothelial cells was pretreated withα-asarone (10, 50, 100 µmol/L) for 1 h, followed by coincubation with Ang II (0.1 µmol/L) for 24 h. Intracellular nitric oxide (NO) and reactive oxygen species (ROS) were detected by fluorescent dyes, and phosphorylation of endothelial nitric oxide synthase (eNOS) atSer1177was determined by Western blotting.α-Asarone dose-dependently mitigated the Ang II-induced intracellular NO reduction (P<0.01versus model) and ROS production (P<0.01versus model). Furthermore, eNOS phosphorylation (Ser1177) by acetylcholine was significantly inhibited by Ang II, while pretreatment for 1 h withα-asarone partially prevented this effect (P<0.05versus model). Additionally, cell viability determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (105~114.5% versus control,P>0.05) was not affected after 24 h of incubation withα-asarone at 1–100 µmol/L. Therefore,α-asarone protects against Ang II-mediated damage of endothelial cells and may be developed to prevent injury to cardiovascular tissues.

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