Guiomar Mendieta

Intake of cooked tomato sauce preserves coronary endothelial function and improves apolipoprotein A-I and apolipoprotein J protein profile in high-density lipoproteins

Intake of tomatoes has been linked with healthy diets (eg, Mediterranean diet). However, it remains unknown whether tomato intake exerts protective effects on the vasculature. The aim of this study was to determine whether medium-term supplementation with cooked tomato sauce (CTS) Mediterranean style (sofrito) attenuates diet-induced coronary endothelial dysfunction in an animal model with clinical impact and explore the mechanisms behind the effects. Pigs (N = 18) were fed a 10-day hypercholesterolemic diet. Half of the animals were given a supplement of 100 g/d of CTS (21.5 mg lycopene per day). Coronary responses to escalating doses of vasoactive drugs (acetylcholine, calcium ionophore, and sodium nitroprusside) and L-NG-monomethylarginine (endothelial nitric oxide synthase [eNOS] inhibitor) were measured using flow Doppler. In the coronary arteries, we investigated eNOS gene expression and activation, monocyte chemoattractant protein 1 (MCP-1) expression, and oxidative DNA damage. In the circulation, we investigated lipoprotein resistance to oxidation and the differential proteomic protein profile. In dyslipidemic animals, CTS intake prevented diet-induced impairment of receptor-operated and nonreceptor-operated endothelial-dependent coronary vasodilation. These beneficial effects were associated with enhanced eNOS transcription and activation and diminished DNA damage in the coronary arteries. CTS-fed animals showed lower lipid peroxidation, higher high-density lipoprotein (HDL) antioxidant potential and plasma lycopene levels of 0.16 mg/L. Interestingly, improved HDL functionality was associated with protein profile changes in apolipoprotein A-I and apolipoprotein J. Lipids levels and MCP-1 expression were not affected by CTS. We report that CTS intake protects against low-density lipoprotein-induced coronary endothelial dysfunction by reducing oxidative damage, enhancing eNOS expression and activity, and improving HDL functionality.

Polyphenol-enriched Diet Prevents Coronary Endothelial Dysfunction by Activating the Akt/eNOS Pathway

INTRODUCTION AND OBJECTIVES The Mediterranean diet, rich in polyphenols, has shown to be cardioprotective. However the mechanisms involved remain unknown. We investigated whether supplementation with a pomegranate extract rich in polyphenols renders beneficial effects on coronary function in a clinically relevant experimental model and characterized the underlying mechanisms. METHODS Pigs were fed a 10-day normocholesterolemic or hypercholesterolemic diet. Half of the animals were given a supplement of 625 mg/day of a pomegranate extract (Pomanox; 200 mg punicalagins/day). Coronary responses to escalating doses of vasoactive drugs (acetylcholine, calcium ionophore, and sodium nitroprusside) and L-NG-monomethylarginine (endothelial nitric oxide-synthase inhibitor) were measured using flow Doppler. Akt/endothelial nitric oxide-synthase axis activation, monocyte chemoattractant protein-1 expression, oxidative deoxyribonucleic acid damage in the coronary artery, and lipoprotein resistance to oxidation were evaluated. RESULTS In dyslipidemic animals, Pomanox supplementation prevented diet-induced impairment of endothelial relaxation, reaching vasodilatory values comparable to normocholesterolemic animals upon stimulation with acetylcholine and/or calcium ionophore. These beneficial effects were associated with vascular Akt/endothelial nitric oxide-synthase activation and lower monocyte chemoattractant protein-1 expression. Pomanox supplementation reduced systemic oxidative stress (higher high-density lipoprotein-antioxidant capacity and higher low-density lipoprotein resistance to oxidation) and coronary deoxyribonucleic acid damage. Normocholesterolemic animals elicited similar drug-related vasodilation regardless of Pomanox supplementation. All animals displayed a similar vasodilatory response to sodium nitroprusside and L-NG-monomethylarginine blunted all vasorelaxation responses except for sodium nitroprusside. CONCLUSIONS Pomanox supplementation hinders hyperlipemia-induced coronary endothelial dysfunction by activating the Akt/endothelial nitric oxide-synthase pathway and favorably counteracting vascular inflammation and oxidative damage.

HMG-CoA reductase inhibition prior reperfusion improves reparative fibrosis post-myocardial infarction in a preclinical experimental model☆

BACKGROUND Studies in patients support a beneficial effect of statin treatment early after acute coronary syndrome and/or prior percutaneous coronary intervention. However, statin effect during total occlusion remains unknown. OBJECTIVES To investigate whether infusion of activated simvastatin during ischemia and prior reperfusion and oral administration thereafter confers cardioprotection and improves cardiac healing in a preclinical model of myocardial infarction. METHODS Pigs (n=24) fed a 10 day Western-type diet underwent a 90 min coronary-balloon occlusion (MI) being randomized to a single intravenous infusion of active β-hydroxy acid derivative of simvastatin (β-OH-S; 0.3 mg/kg) 15 min prior to reperfusion or vehicle. Animals were either sacrificed 2.5 h post-reperfusion or kept under the same regime ± simvastatin (p.o., 20 mg/day) for 3 weeks. Jeopardized and remote myocardium was obtained for molecular/histological studies. Echocardiography was assessed. RESULTS β-OH-S infusion prior to reperfusion reduced coronary and cardiac oxidative DNA-damage, diminished neutrophil infiltration at the site of ischemia, preserved mitochondrial membrane potential and reduced apoptosis in the ischemic myocardium (lower mRNA levels of Fas, casp8, p53, and casp3 and mitochondrial-p-Bcl2; and reduced TUNEL and active caspase-3; p<0.05 vs. vehicle/control). This treatment regime attenuated reperfusion-related arrhythmias and stunning leading to a 40% increased myocardial salvage (p<0.05 vs. vehicle/control). 3 weeks post-MI simvastatin-treated animals showed P-PKCε increase, lower intramyocardial lipotoxicity, TβRII/Smad2/3 signaling restoration and subsequent myofibroblast differentiation and collagen-fibril formation in the evolving scar (p<0.05 vs. control). Simvastatin suppressed cardiac RhoA mobilization and triggered Akt/eNOS signaling. CONCLUSIONS Acute HMG-CoA-reductase inhibition during total ischemia and prior reperfusion limits reperfusion injury and prolonged oral simvastatin treatment thereafter improves cardiac healing post-MI.

Beer elicits vasculoprotective effects through Akt/eNOS activation

There is controversy regarding the effect of alcohol beverage intake in vascular vasodilatory function in peripheral arteries. The effects of beer intake in coronary vasodilation remain unknown. We investigated whether regular beer intake (alcohol and alcohol‐free) protects against hypercholesterolaemia‐induced coronary endothelial dysfunction and the mechanisms behind this effect.

Targeting the molecular mechanisms of ischemic damage: Protective effects of alpha-crystallin-B

AIMS Molecular chaperones constitute protectors of intracellular protein integrity and seem to confer short-term defence against various cell insults. Myocardial damage is associated to a loss of protective chaperones. Ischemic post-conditioning (IPost-Co) is a procedure that seems to protect against reperfusion injury. However, little is known on alpha-crystallin-B-chain (cryab/HspB5) evolution in IPost-Co. Here we have investigated cryab in myocardial ischemia and IPost-Co. METHODS AND RESULTS Pigs underwent closed-chest 1.5h mid-left anterior descending (LAD) balloon occlusion and were either sacrificed without reperfusion (I;N=10), subjected to 2.5h of reperfusion and sacrificed (I/R; N=5); or subjected to IPost-Co before reperfusion and sacrificed 2.5h afterwards (IPost-Co; N=5). A sham-operated group was included (N=6). Proteomic analysis (2-D-electrophoresis/MALDI-TOF/TOF) revealed cryab as a single spot (20kDa; pI7.6). Myocardial cryab-20-protein and cryab-gene expression levels were decreased after ischemia and I/R(P<0.05). After IPost-Co, cryab-20-protein and cryab-gene expression levels were similar to those found in the heart of sham-operated animals (P<0.05). There was a direct correlation between LVEF-improvement after IPost-Co and myocardial cryab-20-protein levels. In a mice proof-of-principle study, cryab-20-peptide was synthesized and administered 1h before LAD-ligation and ECG-proven MI. A 59% reduction in infarct size was achieved in cryab-20-treated animals (P<0.05). CONCLUSIONS Ischemia and reperfusion induce a decrease in myocardial cryab-20-protein levels together with a clinical impairment of cardiac function. IPost-Co induces a clinical improvement of cardiac function and a preservation of cryab-20 levels. Intervention studies on a mice-MI model showed that cryab-20-peptide administration reduces infarct size. All together our results show a significant cardioprotective effect of cryab.

Silybum marianum provides cardioprotection and limits adverse remodeling post-myocardial infarction by mitigating oxidative stress and reactive fibrosis

AIMS Milk thistle (Silybum marianum; SM) is an herb commonly used for hepatoprotection with antioxidant and antifibrotic properties. We investigated in pigs the cardiac effects of SM intake during the acute phase of myocardial infarction (MI) and remodeling period post-MI. METHODS Study-1 tested the effect of SM use on the acute phase of MI. Hence, animals were distributed to a control group or to receive SM prior infarction (1.5 h ischemia). Animals were sacrificed after 2.5 h of reperfusion. Study-2 tested the effect of SM use in the cardiac remodeling phase. Accordingly, animals received for 10 d diet ± SM prior MI and followed the same regime for 3 weeks and then sacrificed. Study-3 tested the effect of SM in a non-infarcted heart; therefore, animals received for 10 d diet ± SM and then sacrificed. RESULTS Animals taking SM before MI showed a reduction in cardiac damage (decreased oxidative damage, ROS production and xanthine oxidase levels; preserved mitochondrial function; and increased myocardial salvage; p < 0.05) versus controls. Animals that remained on chronic SM intake post-MI improved left ventricular remodeling. This was associated with the attenuation of the TGFß1/TßRs/SMAD2/3 signaling, lower myofibroblast transdifferentiation and collagen content in the border zone (p < 0.05 vs. all other groups). Cardiac contractility improved in animals taking SM (p < 0.05 vs. post-MI-control). No changes in cardiac function or fibrosis were detected in animals on SM but without MI. CONCLUSION Intake of SM protects the heart against the deleterious effects of an MI and favors cardiac healing. These benefits may be attributed to the antioxidant and antifibrotic properties of SM.

P2Y12 antagonists and cardiac repair post-myocardial infarction: global and regional heart function analysis and molecular assessments in pigs

Aims P2Y12 antagonists are the standard in antiplatelet therapy but their potential effects on functional myocardial recovery and cardioprotection post-myocardial infarction (MI) are unknown. We investigated in a preclinical model of MI whether ticagrelor and clopidogrel differently affect cardiac repair post-MI. Methods and results Pigs either received: (i) clopidogrel (600 mg; 75 mg/qd); (ii) ticagrelor (180 mg; 90 mg/bid); and (iii) placebo control. MI was induced by mid-left anterior descending coronary artery balloon occlusion (60 min) and animals received the maintenance doses for the following 42 days. Serial cardiac magnetic resonance was performed at Day 3 and Day 42 for the assessment of global and regional cardiac parameters. We determined cardiac AMP-activated protein kinase (AMPK), Akt/PKB, aquaporin-4, vascular density, and fibrosis. In comparison to controls, both P2Y12 antagonists limited infarct expansion at Day 3, although ticagrelor induced a further 5% reduction (P < 0.05 vs. clopidogrel) whereas oedema was only reduced by ticagrelor (≈23% P < 0.05). Scar size decreased at Day 42 in ticagrelor-treated pigs vs. controls but not in clopidogrel-treated pigs. Left ventricular ejection fraction was higher 3 days post-MI in ticagrelor-treated pigs and persisted up to Day 42 (P < 0.05 vs. post-MI). Regional analysis revealed that control and clopidogrel-treated pigs had severe and extensive wall motion abnormalities in the jeopardized myocardium and a reduced myocardial viability that was not as evident in ticagrelor-treated pigs (χ2P < 0.05 vs. ticagrelor). Only ticagrelor enhanced myocardial AMPK and Akt/PKB activation and reduced aquaporin-4 levels (P < 0.05 vs. control and clopidogrel). No differences were observed in vessel density and fibrosis markers among groups. Conclusions Ticagrelor is more efficient than clopidogrel in attenuating myocardial structural and functional alterations post-MI and in improving cardiac healing. These benefits are associated with persistent AMPK and Akt/PKB activation.

Gene Expression, Atherogenesis, and the Mediterranean Diet

Abstract Dietary patterns are well-known modulators of cardiovascular disease (CVD). There is consensus on recommending the Mediterranean diet for the prevention of coronary heart disease. The PREDIMED trial and the Lyon Diet Heart Study have thoroughly demonstrated the protective effects associated with the adherence of a Mediterranean-type diet in primary and secondary prevention of CVD, respectively. These studies have generated enormous interest in identifying the components and mechanisms involved in the protection against CVD and its underlying cause, atherosclerosis. In fact, the Mediterranean diet provides characteristic micro- and macro-nutrients with the capacity to act as dietary signals exerting beneficial effects on health, either directly or through a decrease in reactive oxygen species, eventually modulating gene expression. In the following chapter, we will review the pathogenesis of atherosclerosis and examine the effects of the components of the Mediterranean diet on genes that modulate its progression.

Diferencias en los mecanismos de acción de los nuevos antiagregantes: ¿cómo actúan?

Conventional treatment with aspirin and the thienopyridine clopidogrel has been superseded by the introduction of novel P2Y12 receptor blockers such as prasugrel and ticagrelor. Prasugrel, like all thienopyridines, is administered orally and is an irreversible inhibitor of the receptor. Despite being a prodrug, prasugrel is metabolized more rapidly and effectively than clopidogrel and consequently offers a greater clinical benefit. Ticagrelor is a nucleoside analog that reversibly blocks the receptor and does not require hepatic bioactivation, which makes it a rapid and potent platelet inhibitor. In addition, two other compounds under investigation -cangrelor and elinogrel- are available in intravenous formulations. They have a direct, reversible effect on the P2Y12 receptor and appear to have a better safety profile in patients undergoing coronary surgery. In recent years, all these compounds, and in particular ticagrelor, have been shown to have other clinical benefits in addition to platelet inhibition - their so-called pleiotropic effects.