An enhanced endothelial formation of nitric oxide (NO) by red wine polyphenolic compounds (RWPs) has been involved in the protective effect of chronic intake of red wine on coronary diseases. However, the mechanism underlying the activation of endothelial NO synthase (eNOS) remains unclear. In the presence of indomethacin and charybdotoxin plus apamin to prevent the formation of prostanoids and endothelium-derived hyperpolarizing factor, respectively, RWPs caused pronounced endothelium-dependent relaxations in porcine coronary arteries. Relaxations to RWPs were abolished by N(omega)-nitro-L-arginine (L-NA, a competitive inhibitor of NO synthase) and the membrane permeant analog of superoxide dismutase (SOD), MnTMPyP, and reduced by polyethylene glycol-SOD (PEG-SOD), PEG-catalase and inhibitors of PI3-kinase (wortmannin and LY294002). RWPs caused the L-NA-sensitive formation of NO, as assessed by electron spin resonance spectroscopy and the formation of cyclic guanosine monophosphate in coronary artery endothelial cells; these responses were reduced by MnTMPyP, PEG-catalase, and inhibitors of PI3-kinase. RWPs caused the sustained phosphorylation of Akt and eNOS at Ser1177 in endothelial cells, which were abolished by MnTMPyP and inhibitors of PI3-kinase. These data demonstrate that RWPs induce the redox-sensitive activation of the PI3-kinase/Akt pathway in endothelial cells which, in turn, causes phosphorylation of eNOS, resulting in an increased formation of NO.

Background-The therapeutic effects of nonspecific ␤-blockers are limited by vasoconstriction, thus justifying the interest in molecules with ancillary vasodilating properties. Nebivolol is a selective ␤ 1 -adrenoreceptor antagonist that releases nitric oxide (NO) through incompletely characterized mechanisms. We identified endothelial ␤ 3 -adrenoreceptors in human coronary microarteries that mediate endothelium-and NO-dependent relaxation and hypothesized that nebivolol activates these ␤ 3 -adrenoreceptors. Methods and Results-Nebivolol dose-dependently relaxed rodent coronary resistance microarteries studied by videomicroscopy (10 mol/L, Ϫ86Ϯ6% of prostaglandin F2␣ contraction); this was sensitive to NO synthase (NOS) inhibition, unaffected by the ␤ 1-2 -blocker nadolol, and prevented by the ␤ 1-2-3 -blocker bupranolol (PϽ0.05; nϭ3 to 8). Importantly, nebivolol failed to relax microarteries from ␤ 3 -adrenoreceptor-deficient mice. Nebivolol (10 mol/L) also relaxed human coronary microvessels (Ϫ71Ϯ5% of KCl contraction); this was dependent on a functional endothelium and NO synthase but insensitive to ␤ 1-2 -blockade (all PϽ0.05). In a mouse aortic ring assay of neoangiogenesis, nebivolol induced neocapillary tube formation in rings from wild-type but not ␤ 3 -adrenoreceptor-or endothelial NOS-deficient mice. In cultured endothelial cells, 10 mol/L nebivolol increased NO release by 200% as measured by electron paramagnetic spin trapping, which was also reversed by NOS inhibition. In parallel, endothelial NOS was dephosphorylated on threonine 495 , and fura-2 calcium fluorescence increased by 91.8Ϯ23.7%; this effect was unaffected by ␤ 1-2 -blockade but abrogated by ␤ 1-2-3 -blockade (all PϽ0.05). Conclusions-Nebivolol dilates human and rodent coronary resistance microarteries through an agonist effect on endothelial ␤ 3 -adrenoreceptors to release NO and promote neoangiogenesis. These properties may prove particularly beneficial for the treatment of ischemic and cardiac failure diseases through preservation of coronary reserve.

451H emodynamic overload and ischemic or oxidative stress promote adverse cardiac remodeling, a leading cause of worsening heart failure.1,2 Most of these pathophysiologic conditions are associated with (and to a certain extent, mediated by) adrenergic stimulation and catecholamines release, resulting in adrenoceptor (AR) activation on different cell types within the myocardium. Among these, cardiac myocyte β1-ARs are classically considered to mediate short-term positive effects on all aspects of myocardial contractility; however, long-term stimulation produces adverse effects on myocardial remodeling, in part through activation of calciumdependent prohypertrophic effects, ultimately associated with cardiomyocyte loss. 3,4 Such maladaptive remodeling is usually accompanied by left ventricle (LV) geometry disruption Background-β1-2-adrenergic receptors (AR) are key regulators of cardiac contractility and remodeling in response to catecholamines. β3-AR expression is enhanced in diseased human myocardium, but its impact on remodeling is unknown. Methods and Results-Mice with cardiac myocyte-specific expression of human β3-AR (β3-TG) and wild-type (WT) littermates were used to compare myocardial remodeling in response to isoproterenol (Iso) or Angiotensin II (Ang II). β3-TG and WT had similar morphometric and hemodynamic parameters at baseline. β3-AR colocalized with caveolin-3, endothelial nitric oxide synthase (NOS) and neuronal NOS in adult transgenic myocytes, which constitutively produced more cyclic GMP, detected with a new transgenic FRET sensor. Iso and Ang II produced hypertrophy and fibrosis in WT mice, but not in β3-TG mice, which also had less re-expression of fetal genes and transforming growth factor β1.Protection from Iso-induced hypertrophy was reversed by nonspecific NOS inhibition at low dose Iso, and by preferential neuronal NOS inhibition at high-dose Iso. Adenoviral overexpression of β3-AR in isolated cardiac myocytes also increased NO production and attenuated hypertrophy to Iso and phenylephrine. Hypertrophy was restored on NOS or protein kinase G inhibition. Mechanistically, β3-AR overexpression inhibited phenylephrine-induced nuclear factor of activated T-cell activation. Conclusions-Cardiac-specific overexpression of β3-AR does not affect cardiac morphology at baseline but inhibits the hypertrophic response to neurohormonal stimulation in vivo and in vitro, through a NOS-mediated mechanism. Activation of the cardiac β3-AR pathway may provide future therapeutic avenues for the modulation of hypertrophic remodeling. and interstitial and replacement fibrosis leading to progressive diastolic and systolic heart failure. Deciphering the underlying signaling pathways may lead to new therapeutic strategies that favorably modulate remodeling. The use of β1-AR blockers provided a major advance in this direction, albeit far from totally efficient. 5 The third isotype of β-AR (β3-AR) has classically been considered as a metabolic regulator (eg, by mediating lipolysis in the adipose tissue).6 β3-ARs ...

ObjectiveTo investigate the beneficial role of prebiotics on endothelial dysfunction, an early key marker of cardiovascular diseases, in an original mouse model linking steatosis and endothelial dysfunction.DesignWe examined the contribution of the gut microbiota to vascular dysfunction observed in apolipoprotein E knockout (Apoe−/−) mice fed an n-3 polyunsaturated fatty acid (PUFA)-depleted diet for 12 weeks with or without inulin-type fructans (ITFs) supplementation for the last 15 days. Mesenteric and carotid arteries were isolated to evaluate endothelium-dependent relaxation ex vivo. Caecal microbiota composition (Illumina Sequencing of the 16S rRNA gene) and key pathways/mediators involved in the control of vascular function, including bile acid (BA) profiling, gut and liver key gene expression, nitric oxide and gut hormones production were also assessed.ResultsITF supplementation totally reverses endothelial dysfunction in mesenteric and carotid arteries of n-3 PUFA-depleted Apoe−/− mice via activation of the nitric oxide (NO) synthase/NO pathway. Gut microbiota changes induced by prebiotic treatment consist in increased NO-producing bacteria, replenishment of abundance in Akkermansia and decreased abundance in bacterial taxa involved in secondary BA synthesis. Changes in gut and liver gene expression also occur upon ITFs suggesting increased glucagon-like peptide 1 production and BA turnover as drivers of endothelium function preservation.ConclusionsWe demonstrate for the first time that ITF improve endothelial dysfunction, implicating a short-term adaptation of both gut microbiota and key gut peptides. If confirmed in humans, prebiotics could be proposed as a novel approach in the prevention of metabolic disorders-related cardiovascular diseases.

Nebivolol improves LV dysfunction and survival early after MI likely beyond the effects provided by conventional β₁-receptor blockade. Nebivolol induced effects on NO-mediated endothelial function, early endothelial progenitor cells and inhibition of myocardial NADPH oxidase likely contribute to these beneficial effects of nebivolol early after MI.

The biology of NO (nitric oxide) is poorly explained by the activity of the free radical NO ((.)NO) itself. Although (.)NO acts in an autocrine and paracrine manner, it is also in chemical equilibrium with other NO species that constitute stable stores of NO bioactivity. Among these species, S-nitrosylated hemoglobin (S-nitrosohemoglobin; SNO-Hb) is an evolved transducer of NO bioactivity that acts in a responsive and exquisitely regulated manner to control cardiopulmonary and vascular homeostasis. In SNO-Hb, O(2) sensing is dynamically coupled to formation and release of vasodilating SNOs, endowing the red blood cell (RBC) with the capacity to regulate its own principal function, O(2) delivery, via regulation of blood flow. Analogous, physiological actions of RBC SNO-Hb also contribute to central nervous responses to blood hypoxia, the uptake of O(2) from the lung to blood, and baroreceptor-mediated control of the systemic flow of blood. Dysregulation of the formation, export, or actions of RBC-derived SNOs has been implicated in human diseases including sepsis, sickle cell anemia, pulmonary arterial hypertension, and diabetes mellitus. Delivery of SNOs by the RBC can be harnessed for therapeutic gain, and early results support the logic of this approach in the treatment of diseases as varied as cancer and neonatal pulmonary hypertension.

These data highlight the functional importance of cav-1 for the production of bioactive NO in conduit arteries and its control of central BP variability. Given the impact of the latter on target organ damage, this raises the interest for genetic, pharmacological, or molecular interventions that modulate cav-1 expression in diseases with NO-dependent endothelial dysfunction.

BACKGROUND Nitric oxide (NO) is present in various human solid tumors and tumor cell lines, and it is believed that NO plays an important role in tumor growth. An increased NO concentration catalyzed by NO synthase (NOS) is cytotoxic and can promote apoptosis. The expression of endothelial NOS (e‐NOS) and induced NOS (i‐NOS) was examined in various breast tumors. METHODS Immunohistochemical staining with a monoclonal antibody (Ab) against e‐NOS and a polyclonal Ab against i‐NOS was performed on paraffin embedded tissues from 41 benign breast lesions, 9 in situ breast lesions, and 54 invasive breast lesions. Functionality was confirmed by detection of NO using spin‐trapping electron paramagnetic resonance (EPR) spectroscopy. RESULTS e‐NOS expression was found in 2 benign lesions (5%; 1 fibroadenoma and 1 proliferative mastopathy), in 5 in situ lesions (56%), and in 33 invasive lesions (61%). None of the benign lesions was positive for i‐NOS, but 6 in situ lesions (67%) and 33 invasive lesions (61%) showed tumor cell staining. In particular, capillaries that were embedded in lymphocytic stroma showed a positive reaction for e‐NOS. The functionality of NOS was demonstrated by direct NO formation using the EPR spin‐trapping method. Tumors that were positive for e‐NOS were observed more often in younger patients (P = 0.05). These tumors more frequently were highly differentiated or moderately differentiated and more often showed invasive ductal subtypes and a lower proliferation rate. Tumors that were positive for both e‐NOS and i‐NOS were more likely to be lymph node negative tumors. Both i‐NOS‐expressing lesions and e‐NOS‐expressing lesions showed strong coexpression (P = 0.00001). CONCLUSIONS NOS is detected predominantly in in situ lesions and invasive breast lesions but rarely in benign lesions. NOS is found more frequently in invasive carcinomas with low malignancy. Using the spin‐trapping EPR method, this study demonstrates direct NO formation in human breast tumors for the first time. Cancer 2002;95:1191–8. © 2002 American Cancer Society. DOI 10.1002/cncr.10817