scholarly journals Hepatocyte growth factor activates endothelial nitric oxide synthase by Ca2+- and phosphoinositide 3-kinase/Akt-dependent phosphorylation in aortic endothelial cells

2003 ◽  
Vol 374 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Kennedy MAKONDO ◽  
Kazuhiro KIMURA ◽  
Naoki KITAMURA ◽  
Takanori KITAMURA ◽  
Daisuke YAMAJI ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Endothelial Nitric Oxide Synthase ◽  
Aortic Endothelial Cells ◽  
Enos Activity ◽  
Phosphoinositide 3 Kinase ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Hepatocyte Growth

Hepatocyte growth factor (HGF) causes endothelium-dependent vasodilation, but its relation to endothelial nitric oxide synthase (eNOS) activity remains to be elucidated. Treatment of bovine aortic endothelial cells with HGF increased eNOS activity within minutes, accompanied by an increase of activity-related site-specific phosphorylation of eNOS. The phosphorylation was completely abolished by pretreatment of the cells with a phosphoinositide 3-kinase (PI3K) inhibitor (wortmannin) and by transfection of dominant-negative Akt, and the enzyme activity was inhibited by wortmannin. In addition, eNOS activity and phosphorylation were abolished by pretreatment of the cells with an intracellular Ca2+-chelator, bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM), with a suppression of Akt phosphorylation. These results suggest that HGF stimulates eNOS activity by a PI3K/Akt-dependent phosphorylation in a Ca2+-sensitive manner in vascular endothelial cells.

scholarly journals Superoxide-mediated inactivation of nitric oxide and peroxynitrite formation by tobacco smoke in vascular endothelium: studies in cultured cells and smokers

2009 ◽  
Vol 296 (6) ◽  
pp. H1781-H1792 ◽  
Author(s):  
Gonzalo Peluffo ◽  
Pablo Calcerrada ◽  
Lucia Piacenza ◽  
Nelson Pizzano ◽  
Rafael Radi
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Tobacco Smoke ◽  
Endothelial Nitric Oxide Synthase ◽  
Flow Mediated Dilation ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Tobacco smoke is known to cause nitric oxide (·NO) inactivation and endothelial dysfunction. In this work we evaluated the interplay between·NO and superoxide (O2·−) radicals and the consequent impact on·NO bioavailability and nitroxidative stress in bovine aortic endothelial cells exposed to cigarette smoke extract (CSE) and in smokers. Bovine aortic endothelial cells in the presence of CSE triggered O2·−production as indicated by spin-trapping electron paramagnetic resonance experiments. O2·−was produced both extracellulary (3.4 vs. 1.0 nmol·h−1·mg−1; CSE vs. control; cytochrome c3+reduction assay) and intracellularly (40% inhibition of cytosolic aconitase). CSE also led to the production of peroxynitrite as evaluated by dihydrorhodamine oxidation and protein tyrosine nitration on cells. O2·−and peroxynitrite formation were decreased by ascorbate and α-tocopherol. Additionally, CSE led to the oxidation of endothelial nitric oxide synthase increasing the monomeric inactive form of endothelial nitric oxide synthase. Smokers and age-matched healthy volunteers were supplemented orally with 500 mg ascorbate plus 400 IU all-rac-α-tocopherol every 12 h for 165 days. Smokers had endothelial dysfunction compared with control subjects (95% confidence interval: 2.5, 8.3 vs. 10.6, 14.2; P < 0.05) as assessed by flow-mediated dilation of the brachial artery, and plasma levels of protein 3-nitrotyrosine were 1.4-fold higher. The loss of flow-mediated dilation in smokers reverted after a long-term antioxidant supplementation (95% confidence interval: 13.9, 19.9; P < 0.05), reaching values comparable with the control population. Our data indicate that elements on tobacco smoke, most likely through redox cycling, divert·NO toward peroxynitrite by inducing O2·−production in vascular endothelial cells both in vitro and in vivo.

Abstract 3635: Inhibition of Inhibitor Kappa B Kinase Beta Augments Endothelial Nitric Oxide Synthase Activity and Nitric Oxide Production in Aortic Endothelial Cells

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Sumathy Mohan ◽  
Ryzard Konopinski ◽  
Mohan Natarajan
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Vascular Endothelial Cells ◽  
No Production ◽  
Enos Activity ◽  
Hsp 90 ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

A decline in the bioavailability of nitric oxide (NO) that causes endothelial dysfunction is a hall-mark of diabetes. The availability of NO to the vasculature is regulated by endothelial nitric oxide synthase (eNOS) activity and the involvement of heat shock protein 90 (Hsp-90) in the regulation of eNOS activity has been demonstrated. Hsp-90 has been shown to interact with upstream kinases (inhibitor kappa B kinases α, β and γ) in non-vascular cells. In this study, we have investigated the interaction of Hsp-90-IKKβ in endothelial cells under conditions of high glucose (HG) as a possible mechanism that diminishes Hsp-90-eNOS interaction, which could contribute to reduced bioavailability of NO. We report for the first time that IKKβ interacts with Hsp-90 and this interaction is augmented by HG in vascular endothelial cells. HG also augments transcriptional (4.02 ± 0.81-folds) and translational (1.97 ± 0.17-fold) expression as well as the catalytic activity of IKKβ (2.04 ± 0.06-folds). Another important and novel finding is that both IKKβ and eNOS could be co-immunoprecipitated with Hsp-90 (Figures A & B ) thus indicating the possible existence of a complex of IKKβ and eNOS interacting with single pool of Hsp-90. Inhibition of Hsp-90 with geldanamycin (2μM) or Radicicol (20μM) mitigated (0.45 ± 0.04 -fold and 0.93 ± 0.16-fold, respectively) HG induced-IKKβ activity (2.5 ± 0.416-fold). Blocking of IKKβ expression by IKK inhibitor II (15μM wedelolactone) or siRNA improved Hsp-90-eNOS interaction and NO production under conditions of HG. These results illuminate a possible mechanism for the declining eNOS activity reported under conditions of HG.

scholarly journals Phytoestrogen Genistein Up-Regulates Endothelial Nitric Oxide Synthase Expression Via Activation of cAMP Response Element-Binding Protein in Human Aortic Endothelial Cells

Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 3190-3198 ◽  
Author(s):  
Hongwei Si ◽  
Jie Yu ◽  
Hongling Jiang ◽  
Hazel Lum ◽  
Dongmin Liu
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
No Production ◽  
Enos Expression ◽  
Camp Response Element ◽  
Aortic Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Human Aortic Endothelial Cells

We previously reported that genistein, a phytoestrogen, up-regulates endothelial nitric oxide synthase (eNOS) and prevents hypertension in rats that are independent of estrogen signaling machinery. However, how genistein regulates eNOS expression is unknown. In the present study, we show that genistein enhanced eNOS expression and NO synthesis in primary human aortic endothelial cells. Inhibition of extracellular signal regulated kinase, phosphoinositol-3 kinase, or protein kinase C did not affect genistein-enhanced eNOS expression and NO synthesis. However, chemical inhibition of protein kinase A (PKA) or adenoviral transfer of the specific endogenous PKA inhibitor gene completely abolished PKA activity and genistein-stimulated eNOS expression and NO production. Accordingly, genistein induced PKA activity and subsequent phosphorylation of cAMP response element (CRE)-binding protein (CREB) at Ser133. Suppression of CREB by small interfering RNA transfection abolished genistein-enhanced eNOS expression and NO production. Consistently, deletion of the CRE site within human eNOS promoter eliminated genistein-stimulated eNOS promoter activity. These findings provide the first evidence to our knowledge that genistein may play a beneficial role in vascular function through targeting the PKA/CREB/eNOS/NO signaling pathway.

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