scholarly journals A Common CD36 Variant Influences Endothelial Function and Response to Treatment with Phosphodiesterase 5 Inhibition

2016 ◽  
Vol 101 (7) ◽  
pp. 2751-2758 ◽  
Author(s):  
Cyndya A. Shibao ◽  
Jorge E. Celedonio ◽  
Claudia E. Ramirez ◽  
Latisha Love-Gregory ◽  
Amy C. Arnold ◽  
...  

Context: The scavenger receptor CD36 influences the endothelial nitric oxide-cGMP pathway in vitro. Genetic variants that alter CD36 level are common in African Americans (AAs), a population at high risk of endothelial dysfunction. Objective: To examine if the minor allele (G) of coding CD36 variant rs3211938 (G/T) which reduces CD36 level by approximately 50% influences endothelial function, insulin sensitivity (IS), and the response to treatment with the nitric oxide-cGMP potentiator sildenafil. Design: IS (frequently sampled iv glucose tolerance) and endothelial function (flow mediated dilation [FMD]) were determined in age- and body mass index-matched obese AA women with or without the G allele of rs3211938 (protocol 1). Effect of chronic sildenafil treatment on IS and FMD was tested in AA women with metabolic syndrome and with/without the CD36 variant, using a randomized, placebo-controlled trial (protocol 2). Setting: Two-center study. Participants: Obese AA women. Intervention: A total of 20-mg sildenafil citrate or placebo thrice daily for 4 weeks. Main outcome: IS, FMD. Results: G allele carriers have lower FMD (P = .03) and cGMP levels (P = .01) than noncarriers. Sildenafil did not improve IS, mean difference 0.12 (95% confidence interval [CI], −0.33 to 0.58; P = .550). However, there was a significant interaction between FMD response to sildenafil and rs3211938 (P = .018). FMD tended to improve in G carriers, 2.9 (95% CI, −0.9 to 6.8; P = .126), whereas it deteriorated in noncarriers, −2.6 (95% CI, −5.1 to −0.1; P = .04). Conclusions: The data document influence of a common genetic variant on susceptibility to endothelial dysfunction and its response to sildenafil treatment.

2012 ◽  
Vol 302 (5) ◽  
pp. E481-E495 ◽  
Author(s):  
Rinrada Kietadisorn ◽  
Rio P. Juni ◽  
An L. Moens

Endothelial nitric oxide synthase (eNOS) serves as a critical enzyme in maintaining vascular pressure by producing nitric oxide (NO); hence, it has a crucial role in the regulation of endothelial function. The bioavailability of eNOS-derived NO is crucial for this function and might be affected at multiple levels. Uncoupling of eNOS, with subsequently less NO and more superoxide generation, is one of the major underlying causes of endothelial dysfunction found in atherosclerosis, diabetes, hypertension, cigarette smoking, hyperhomocysteinemia, and ischemia/reperfusion injury. Therefore, modulating eNOS uncoupling by stabilizing eNOS activity, enhancing its substrate, cofactors, and transcription, and reversing uncoupled eNOS are attractive therapeutic approaches to improve endothelial function. This review provides an extensive overview of the important role of eNOS uncoupling in the pathogenesis of endothelial dysfunction and the potential therapeutic interventions to modulate eNOS for tackling endothelial dysfunction.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Cyndya A Shibao ◽  
Jorge E Celedonio ◽  
Latisha Gregory-Love ◽  
Claudia E Ramirez ◽  
Amy C Arnold ◽  
...  

CD36, a scavenger receptor expressed on endothelial cells, interacts with thrombospodin-1, a matrix protein that modulates nitric oxide-soluble guanylate cyclase (NO-sGC) signaling. CD36 genetic variants associate with endothelial dysfunction, atherosclerosis, hypertension and insulin resistance. A coding variant of CD36 (rs3211938, G/T genotype) that causes partial CD36 deficiency (50% reduction) is common (~18%) in African Americans (AA); however, it is unknown, if this genotype influences NO-dependent endothelial function. This study examined whether potentiating NO-sGC pathways with the phosphodiesterase 5 inhibitor, sildenafil citrate, improves endothelial function and insulin sensitivity in AA women with or without the G/T genotype. Forty-six AA women with metabolic syndrome (MetS) participated in a 4-week, parallel-arm, double-blind, and placebo-controlled study. Carefully matched subjects were randomly assigned to sildenafil citrate 20 mg TID versus placebo; sildenafil (n= 23, 42±10 years old, BMI 39±5 kg/m2, fasting insulin 15±8 uU/ml) and placebo (n=23, age 43±10, BMI 39±6 kg/m2, fasting insulin 14±10 uU/ml). Primary endpoints were insulin sensitivity and endothelial function measured by intravenous glucose tolerance test and flow mediated dilation, respectively. Treatment compliance was documented with plasma sildenafil levels (mean 57±50 ng/ml). There was no difference in insulin sensitivity (p=0.676) or flow-mediated dilation (p=0.649) between intervention groups. However, subgroup analyses showed a significant interaction between sildenafil citrate treatment and G/T genotype (p=0.018). Sildenafil citrate improved endothelial function in G/T carriers (the mean difference: 2.9, the 95% CI: -0.90 to 6.8, p = 0.126) and decreased endothelial function in T/T carriers (the mean difference: -2.6, the 95% CI: -5.1 to -0.1, p = 0.040). We conclude that the rs3211938 common CD36 genetic variant influences NO-dependent endothelial function in response to chronic treatment with phosphodiesterase 5 inhibition. Further studies are needed to determine if rs3211938 and other common CD36 genotypes influence endothelial function and the inter-individual variability in response to the drug.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Abel Romero Corral ◽  
Justo Sierra-Johnson ◽  
Marek Orban ◽  
Apoor S Gami ◽  
Fatima H Sert Kuniyoshi ◽  
...  

Background: Endothelial dysfunction assessed by flow mediated dilation (FMD) of the brachial artery has been identified as an independent predictor of cardiovascular events. However, whether weight gain impairs endothelial function is unknown. Methods: A randomized blinded controlled-trial to assess the effects of weight gain on endothelial function. After a weight maintenance period supervised by an experience dietitian, volunteers were randomized to gain weight (4 kg) or maintain weight. We recruited lean (BMI 18.5–24.9 kg/m 2 ) healthy volunteers (no diseases, medications and non-smokers) from the community. Using ultrasound, endothelial function was measured by FMD and non-flow mediated dilation (NFMD) of the brachial artery in the early morning (6:30 a.m.). Endothelial function was measured at baseline, after fat gain at 8 weeks and after weight loss at 16 weeks for fat-gainers and at baseline and follow-up (8 weeks) for weight maintainers. Body composition techniques to measure body fat %, such as dual x-ray absorptiometry and abdominal CT scans were performed. Results: We recruited 35 fat-gainers and 8 weight maintainers. Mean age was 29 ± 6 years and 18 (42 %) were women. There were no differences in age, anthropometric and body composition measurements, blood pressure, heart rate or apnea hypopnea index at baseline between both groups. After an average gain of 4 kg, the fat-gainer group significantly increased their total, visceral and subcutaneous fat. Brachial artery FMD and NFMD remained unchanged in weight maintainers. However, it decreaed in fat-gainers (FMD=9.1 ± 3 vs. 7.6 ± 3.2, p=0.003 and NFMD=12.0 ± 4.9 vs. 10.1 ± 6.0, p=0.01), but recovered to baseline after subjects shed the gained weight (basleline vs. recovery: FMD=9.1 ± 3 vs. 9.0 ± 3, p=NS and NFMD =12.0 ± 4.9 vs.12.6 ± 5.0, p=NS). Visceral fat gain, but not subcutaneous fat gain was significantly correlated with the decrease in brachial artery FMD (rho =−0.42, p=0.004 and rho =−0.22, p=0.15, respectively). Conclusions: In lean healthy young subjects, modest weight gain results in impaired endothelial function, even in the absence of changes in blood pressure. Endothelial funcion recovers after weight loss. Viscerar rather than subcutaneous fat predicts endothelial dysfunction.


2009 ◽  
Vol 296 (6) ◽  
pp. H1781-H1792 ◽  
Author(s):  
Gonzalo Peluffo ◽  
Pablo Calcerrada ◽  
Lucia Piacenza ◽  
Nelson Pizzano ◽  
Rafael Radi

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.


2015 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Wai Keung Christopher Lai ◽  
Ming Yin Kan

This review discussed and in particular emphasis the potential cellular pathways and the biological processes involved that lead to homocysteine-induced endothelial dysfunction, in particular in the impaired endothelial dependent dilatation aspect. Hyperhomocysteinemia is an independent cardiovascular risk factor that has been associated with atherosclerotic vascular diseases and ischemic heart attacks. The potential mechanisms by which elevated plasma homocysteine level leads to reduction in nitric oxide bioavailability include the disruptive uncoupling of nitric oxide synthase activity and quenching of nitric oxide by oxidative stress, the enzymatic inhibition by asymmetric dimethylarginine, endoplasmic reticulum stress with eventual endothelial cell apoptosis, and chronic inflammation/prothrombotic conditions. Homocysteine-induced endothelial dysfunction presumably affecting the bioavailability of the potent vasodilator ‘nitric oxide', and such dysfunction can easily be monitor by flow-mediated dilation method using ultrasound. Understanding the mechanisms by which plasma homocysteine alter endothelial nitric oxide production is therefore essential in the comprehension of homocysteine-induced impairment of endothelial dependent dilatation, and its association of cardiovascular risk and its pathophysiology.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Anna E Dikalova ◽  
Hana A Itani ◽  
Arvind K Pandey ◽  
David G Harrison ◽  
Sergey I Dikalov

We have recently reported SOD2 hyperacetylation and reduced Sirt3 level in human subjects with essential hypertension. We hypothesized that diminished Sirt3 expression promotes endothelial dysfunction and hypertension while Sirt3 overexpression protects endothelial function and attenuates hypertension. Indeed, hypertension was markedly increased in Sirt3 knockout (Sirt3 -/- ) in response to angiotensin II (0.7 mg/kg/day) compared with wild-type C57Bl/6J mice. Sirt3 depletion caused SOD2 inactivation due to SOD2 hyperacetylation, increased mitochondrial O 2 • and diminished endothelial nitric oxide. Angiotensin II infusion in wild-type mice was associated with Sirt3 inactivation and SOD2 hyperacetylation in aorta and kidney. To test the specific role of Sirt3 in vasculature we have generated tamoxifen-inducible endothelium specific Sirt3 knockout mice (Ec Sirt3 KO ) and tamoxifen-inducible smooth muscle specific Sirt3 knockout mice (Smc Sirt3 KO ). Deletion of Sirt3 in smooth muscle exacerbated hypertension (165 mm Hg vs 155 mm Hg in wild-type) and significantly increased mortality in angiotensin II infused Smc Sirt3 KO mice (30% vs 3% in wild-type) which was associated with higher rate of aortic aneurysm. Ec Sirt3 KO mice had elevated basal blood pressure by 12 mm Hg and hypertension was exacerbated in Ec Sirt3 KO mice accompanied by impaired vascular relaxation and reduced endothelial nitric oxide. Treatment of angiotensin II-infused Sirt3 -/- mice with SOD2 mimetic mitoTEMPO rescued endothelial-dependent relaxation and reduced blood pressure. We tested if Sirt3 overexpression protects endothelial function and attenuates angiotensin II-induced hypertension. These new mice were obtained by crossing the EIIa-cre with Sirt3flox mice resulting in constitutively increased Sirt3 in the whole body. Sirt3 overexpression abolished angiotensin II induced impairment of vasorelaxation and attenuated development of hypertension. Our data suggest that diminished Sirt3 activity leads to SOD2 hyperacetylation and contributes to the pathogenesis of hypertension. It is conceivable that Sirt3 agonists and SOD2 mimetics may have therapeutic potential in cardiovascular disease.


2008 ◽  
Vol 294 (2) ◽  
pp. H801-H809 ◽  
Author(s):  
Xiaowei Sun ◽  
David D. Ku

We recently reported that increased vascular endothelial nitric oxide production could protect against the development of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and right ventricular hypertrophy (RVH) in rats ( 32 ). The present study investigated whether the pleiotropic action of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors in upregulating endothelial function could also protect against the MCT-induced end-organ damages. Rosuvastatin (2 mg·kg−1·day−1 via oral gavage) or placebo was initiated 1 wk before or 1 wk after MCT (60 mg/kg ip) administration. One month after MCT, significant PAH developed in the placebo rats, which were accompanied by histological evidence of pulmonary vascular thickening and right ventricular hypertrophy. The coronary endothelial vasodilatory function, assessed with endothelial/nitric oxide-dependent responses to acetylcholine and NG-nitro-l-arginine methyl ester (l-NAME), was depressed, while the constrictory responses to known coronary constrictors was enhanced. In rats that received rosuvastatin treatment 1 wk before MCT administration, a significantly reduced PAH and RVH was observed, as well as reduced pulmonary vascular and right ventricular remodelings. Rosuvastatin 1-wk posttreatment had no effect on PAH, but inhibited RVH. Right coronary endothelial dysfunction, which was shown in placebo rats, was effectively prevented by both pre- and postrosuvastatin treatment, while this effect was more dramatic in the pretreated group. Left coronary endothelial function, which was not affected by MCT, also showed an upregulation by rosuvastatin. Taken together, our results demonstrated the pleiotropic protection of rosuvastatin against the development of PAH and RVH and confirmed our previous finding that the targeted preservation of coronary endothelial function and vasoactivity may provide a novel approach to protect against cardiac remodeling.


2010 ◽  
Vol 112 (3) ◽  
pp. 586-594 ◽  
Author(s):  
Binglan Yu ◽  
Mohd Shahid ◽  
Elena M. Egorina ◽  
Mikhail A. Sovershaev ◽  
Michael J. Raher ◽  
...  

Background To date, there is no safe and effective hemoglobin-based oxygen carrier (HBOC) to substitute for erythrocyte transfusion. It is uncertain whether a deficiency of endothelial nitric oxide bioavailability (endothelial dysfunction) prevents or augments HBOC-induced vasoconstriction. Methods Hemodynamic effects of infusion of PolyHeme (1.08 g hemoglobin/kg; Northfield Laboratories, Evanston, IL) or murine tetrameric hemoglobin (0.48 g hemoglobin/kg) were determined in awake healthy lambs, awake mice, and anesthetized mice. In vitro, a cumulative dose-tension response was obtained by sequential addition of PolyHeme or tetrameric hemoglobin to phenylephrine-precontracted murine aortic rings. Results Infusion of PolyHeme did not cause systemic hypertension in awake lambs but produced acute systemic and pulmonary vasoconstriction. Infusion of PolyHeme did not cause systemic hypertension in healthy wild-type mice but induced severe systemic vasoconstriction in mice with endothelial dysfunction (either db/db mice or high-fat fed wild-type mice for 4-6 weeks). The db/db mice were more sensitive to systemic vasoconstriction than wild-type mice after the infusion of either tetrameric hemoglobin or PolyHeme. Murine aortic ring studies confirmed that db/db mice have an impaired response to an endothelial-dependent vasodilator and an enhanced vasoconstrictor response to HBOC. Conclusions Reduction in low molecular weight hemoglobin concentrations to less than 1% is insufficient to abrogate the vasoconstrictor effects of HBOC infusion in healthy awake sheep or in mice with reduced vascular nitric oxide levels associated with endothelial dysfunction. These findings suggest that testing HBOCs in animals with endothelial dysfunction can provide a more sensitive indication of their potential vasoconstrictor effects.


2014 ◽  
Vol 13 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Bruno Costa Teixeira ◽  
André Luiz Lopes ◽  
Rodrigo Cauduro Oliveira Macedo ◽  
Cleiton Silva Correa ◽  
Thiago Rozales Ramis ◽  
...  

The need to study cardiovascular diseases (CVD) has become more and more relevant as their prevalence has increased over the years. An intact endothelial wall is essential to vascular health. Certain factors are responsible for maintaining this tissue intact, including nitric oxide (NO), which provokes dilation of blood vessels in response to shear stress. Expression of the endothelial nitric oxide synthase (eNOS) enzyme, which produces nitric oxide in response to increases in blood flow, is of fundamental importance to maintenance of the vascular system. When this enzyme is inhibited, nitric oxide production is reduced, causing endothelial dysfunction. Since C-reactive protein inhibits production of nitric oxide by the eNOS enzyme, it is one of the causes of endothelial dysfunction and cardiovascular events. The objective of the present study was to review scientific articles in the literature related to the subject 'inflammatory markers and endothelial function'. A wide-ranging review of the current literature was conducted, using systematic analysis of bibliographic references indexed in PubMed, Scielo, Medline and LILACS database, for the years 1992 to 2013. The studies reviewed show that increases in inflammation causes reductions in NO and increases in cardiovascular events. Increased inflammation is associated with higher incidence of cardiovascular diseases.


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