Grape juice causes endothelium-dependent relaxation via a redox-sensitive Src- and Akt-dependent activation of eNOS

Département de Pharmacologie et Physico-Chimie, UMR 7175-LC1, Université Louis Pasteur de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France.
Cardiovascular Research (Impact Factor: 5.94). 02/2007; 73(2):404-13. DOI: 10.1016/j.cardiores.2006.08.004
Source: PubMed


An enhanced endothelial formation of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), is thought to contribute to the protective effect of moderate consumption of red wine on coronary diseases. The present study has characterized endothelium-dependent relaxations to Concord grape juice (CGJ), a non-alcoholic rich source of grape-derived polyphenols, in the coronary artery.
Porcine coronary artery rings were suspended in organ chambers for the measurement of changes in isometric tension in the presence of indomethacin. NO formation was assessed by electron spin resonance spectroscopy, and the phosphorylation of Src, Akt and endothelial NO synthase (eNOS) by Western blot analysis in cultured endothelial cells.
Endothelium-dependent relaxations to CGJ were slightly but significantly reduced by L-NA, not affected by charybdotoxin (CTX) plus apamin (APA, two inhibitors of EDHF-mediated responses) whereas the combination of L-NA, CTX plus APA reduced maximal relaxation to about 50%. In the presence of CTX plus APA, relaxations to CGJ were markedly reduced by the membrane permeant mimetic of superoxide dismutase (SOD), MnTMPyP, the membrane permeant analogue of catalase polyethyleneglycol-catalase (PEG-catalase), PP2, an inhibitor of Src kinase, and by wortmannin, an inhibitor of the PI3-kinase. CGJ stimulated the formation of reactive oxygen species and the N(omega)-nitro-L-arginine-, PP2- and wortmannin-sensitive formation of NO in endothelial cells. The formation of NO was associated with a redox-sensitive and time-dependent phosphorylation of Src, Akt and eNOS.
CGJ induces endothelium-dependent relaxations of coronary arteries, which involve a NO-mediated component and also, to a minor extent, an EDHF-mediated component. In addition, CGJ-induced NO formation is due to the redox-sensitive activation of Src kinase with the subsequent PI3-kinase/Akt-dependent phosphorylation of eNOS.

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Available from: Thierry Chataigneau, Oct 13, 2014
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    • "It has also been proposed that reactive oxygen species (ROS) play a role in RCM toxicity [23] [24] [25] [26] and in vivo studies using rats fed with the antioxidants alpha-tocopherol [27] and grape seed proanthocyanidin extract [28] were seen to be protective against renal tissue damage due to RCM. Given that grape juice is a rich source of antioxidants and has been shown to increase serum antioxidant capacity in adults [29] and given that it has also been shown that Concord grape juice may activate Akt kinase by increasing its phosphorylation at Ser 473 [30], it seemed feasible that grape juice may afford protection against the toxic effects of RCM. On this basis, we set out to test the action of a white grape juice extract (WGJe) on culture human renal proximal tubule cells (HK-2) treated with the high-osmolar contrast medium sodium diatrizoate and in particular to focus on any changes in the signaling pathways in these cells. "
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    ABSTRACT: Radiocontrast media (RCM)-induced nephrotoxicity (CIN) is a major clinical problem accounting for 12% of all hospital-acquired cases of acute kidney injury. The pathophysiology of CIN is not well understood, but direct toxic effects on renal cells have been postulated as contributing to CIN. We have investigated the effect of a white grape (Vitis vinifera) juice extract (WGJe) on human renal proximal tubular (HK-2) cells treated with the radiocontrast medium (RCM) sodium diatrizoate. WGJe caused an increase in phosphorylation of the prosurvival kinases Akt and ERK1/2 in HK-2 cells. Treatment of HK-2 cells with 75 mg I/ml sodium diatrizoate for 2.5 h and then further incubation (for 27.5 h) after removal of the RCM caused a drastic decrease in cell viability. However, pre-treatment with WGJe, prior to incubation with diatrizoate, dramatically improved cell viability. Analysis of key signaling molecules by Western blotting showed that diatrizoate caused a drastic decrease in phosphorylation of Akt (Ser473), FOXO1 (Thr24) and FOXO3a (Thr32) during the initial 2.5 h incubation period, and WGJe pre-treatment caused a reversal of these effects. Further analysis by Western blotting of samples from HK-2 cells cultured for longer periods of time (for up to 27.5 h after an initial 2.5 h exposure to diatrizoate with or without WGJe pre-treatment) showed that WGJe pre-treatment caused a negative effect on phosphorylation of p38, NF-kappa B (Ser276) and pERK1/2 whilst having a positive effect on the phosphorylation of Akt, FOXO1/FOXO3a and maintained levels of Pim-1 kinase. WGJe may alleviate RCM toxicity through modulation of signaling molecules that are known to be involved in cell death and cell survival and its possible beneficial effects should be further investigated.
    Full-text · Article · Jan 2015 · Chemico-Biological Interactions
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    • "Indeed, inhibitors of either Src kinase, PI3-kinase, JNK, p38 MAPK or MEK reduced NO-mediated relaxations to EPA:DHA 6∶1, and EPA:DHA 6∶1 increased the phosphorylation level of activator sites of Src, Akt, JNK, p38 MAPK, ERK and eNOS in endothelial cells. Of interest, the Src/PI3-kinase/Akt pathway has also been shown to mediate the stimulatory effect of other natural products containing high levels of polyphenols such as grape-derived products and tea catechins on eNOS [17], [18], [22], [23]. Similarly to polyphenols [17], [18], [22], [23], the intracellular formation of ROS, in particular superoxide anions and hydrogen peroxide, mediates the stimulatory effect on the Src/PI3-kinase/Akt and MAPKs pathways leading to eNOS activation in response to EPA:DHA 6∶1. "
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    ABSTRACT: Aims Omega-3 fatty acid products containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have vasoprotective effects, in part, by stimulating the endothelial formation of nitric oxide (NO). This study determined the role of the EPA:DHA ratio and amount, and characterized the mechanism leading to endothelial NO synthase (eNOS) activation. Methods and Results EPA:DHA 6∶1 and 9∶1 caused significantly greater endothelium-dependent relaxations in porcine coronary artery rings than EPA:DHA 3∶1, 1∶1, 1∶3, 1∶6, 1∶9, EPA and DHA alone, and EPA:DHA 6∶1 with a reduced EPA + DHA amount, which were inhibited by an eNOS inhibitor. Relaxations to EPA:DHA 6∶1 were insensitive to cyclooxygenase inhibition, and reduced by inhibitors of either oxidative stress, Src kinase, PI3-kinase, p38 MAPK, MEK, or JNK. EPA:DHA 6∶1 induced phosphorylation of Src, Akt, p38 MAPK, ERK, JNK and eNOS; these effects were inhibited by MnTMPyP. EPA:DHA 6∶1 induced the endothelial formation of ROS in coronary artery sections as assessed by dihydroethidium, and of superoxide anions and hydrogen peroxide in cultured endothelial cells as assessed by electron spin resonance with the spin probe CMH, and the Amplex Red based assay, respectively. Conclusion Omega-3 fatty acids cause endothelium-dependent NO-mediated relaxations in coronary artery rings, which are dependent on the EPA:DHA ratio and amount, and involve an intracellular activation of the redox-sensitive PI3-kinase/Akt and MAPKs pathways to activate eNOS.
    Full-text · Article · Aug 2014 · PLoS ONE
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    • "and as a mimetic of superoxide dismutase (SOD) exerted an SOD-like endothelium-dependent effect on the porcine coronary artery contraction in vitro [16]. Furthermore, externally administered porphyrin-based photosensitisers have been demonstrated to accumulate in blood vessels of malignant tumours and surrounding healthy tissue. "
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