Publications by authors named "Alain Grynberg"

Despite significant advances in the understanding of the therapeutic activity of antidepressant drugs, treatment-resistant depression is a public health issue prompting research to identify new therapeutic strategies. Evidence strongly suggests that nutrition might exert a significant impact on the onset, the duration and the severity of major depression. Accordingly, preclinical and clinical investigations demonstrated the beneficial effects of omega-3 fatty acids in anxiety and mood disorders.

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The preservation of a constant pool of free cholesterol (FC) is critical to ensure several functions of cardiomyocytes. We investigated the impact of the membrane incorporation of arachidonic acid (C20:4 ω6, AA) or docosahexaenoic acid (C22:6 ω3, DHA) as ω6 or ω3 polyunsaturated fatty acids (PUFAs) on cholesterol homeostasis in primary cultures of neonatal rat cardiac myocytes. We measured significant alterations to the phospholipid FA profiles, which had markedly different ω6/ω3 ratios between the AA and DHA cells (13 vs.

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Purpose: To study, in high-fructose-fed rats, the effect of a dietary enrichment in omega-3 polyunsaturated fatty acids (n-3 PUFA) on the expression of genes involved in lipid metabolism and cardiovascular function.

Methods: Twenty-eight male "Wistar Han" rats received for 8 weeks, either a standard chow food or an isocaloric 67% fructose diet enriched or not in alpha-linolenic acid (ALA) or in docosahexaenoic (DHA) and eicosapentaenoic acids (EPA) mix (DHA/EPA). After sacrifice, blood was withdrawn for biochemical analyses; heart, periepididymal adipose tissue and liver were collected and analyzed for the expression of 22 genes by real-time PCR.

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Although cholesterol-rich microdomains are highly involved in the functions of cardiomyocytes, the cholesterol homeostasis is largely unknown in these cells. We developed experimental procedures to assess cholesterol synthesis, cholesterol masses and cholesterol efflux from primary cultures of cardiac myocytes obtained from 2 to 4 days old Wistar rats. We first observed that cardiomyocytes poorly internalized exogenously supplied native or modified LDL and that free cholesterol (FC) efflux to free apolipoprotein AI (apo AI) and to HDL was mediated by ATP binding cassette transporter A1 (ABCA1) and likely by ATP binding cassette transporter G1 (ABCG1), respectively, which are both upregulated by liver X receptor/retinoid X receptor (LXR/RXR) activation.

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Consumption of trans fatty acids (TFA) increase cardiovascular risk more than do saturated FA, but the mechanisms explaining their atherogenicity are still unclear. We investigated the impact of membrane incorporation of TFA on cholesterol efflux by exposing J774 mouse macrophages or human monocyte-derived macrophages (HMDM) to media enriched or not (standard medium) with industrially produced elaidic (trans-9 18:1) acid, naturally produced vaccenic (trans-11 18:1) acid (34 h, 70 μM) or palmitic acid. In J774 macrophages, elaidic and palmitic acid, but not vaccenic acid, reduced ABCA1-mediated efflux by ~23% without affecting aqueous diffusion, SR-BI or ABCG1-mediated pathways, and this effect was maintained in cholesterol-loaded cells.

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Aim: Dietary supplements in polyunsaturated fatty acids (PUFA), particularly omega-3, are well known for their beneficial effects in preventing cardiovascular diseases (CVD). The aim of this study was to determine the role of PUFA on the modulation of apoptosis induced by hypochlorous acidoxidized LDL (HOCl-oxLDL) in U937 cells.

Methods: We tested the effect of monocyte cell line U937 supplementation with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (ARA) or oleic acid (OA) on the modulation of HOCl-oxLDL-induced apoptosis.

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Metabolic programming and metabolic imprinting describe early life events, which impact upon on later physiological outcomes. Despite the increasing numbers of papers and studies, the distinction between metabolic programming and metabolic imprinting remains confusing. The former can be defined as a dynamic process whose effects are dependent upon a critical window(s) while the latter can be more strictly associated with imprinting at the genomic level.

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Trimetazidine (TMZ), a partial inhibitor of fatty acid oxidation, has been effective in treating chronic angina, but its effects on the development of post-myocardial infarction (MI) left ventricular remodeling are not defined. In this study, we tested whether chronic pre-MI administration of TMZ would be beneficial during and after acute MI. Two-hundred male Wistar rats were studied in four groups: sham + TMZ diet (n = 20), sham + control diet (n = 20), MI + TMZ diet (n = 80), and MI + control diet (n = 80) splitted into one short-term and one long-term experiments.

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Background: Olive oil and fish oils are known to possess beneficial properties for human health. We investigated whether different oils and fatty acids alone were able to decrease oxidative stress induced on corneal cells.

Methods: In our in vivo study, rats were fed with marine oils rich in polyunsaturated fatty acids (PUFA) or refined olive oil during 28 days.

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Since android overweight/obesity and insulin resistance are independent risk factors for cardiovascular disease, we investigated their impact on basal and postprandial scavenger receptor BI (SR-BI) and ATP binding cassette transporter A1 (ABCA1)-mediated serum cholesterol efflux. Twelve android overweight to obese and 9 normal weight controls women underwent body composition analysis by dual energy X-ray absorptiometry, a euglycemic hyperinsulinemic clamp, and an oral fat load with blood sampling at initial time (T0), 4h (T4) and 10h (T10) after the fat load. Serum lipids and HDL-parameters, capacities of serum to promote cholesterol efflux from SR-BI expressing Fu5AH hepatoma cells or from ABCA1-expressing J774 macrophages and to abilities of serum to induce a net removal of cholesterol from macrophage foam cells were measured at T0, T4 and T10.

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This study was designed to evaluate the effects of individual dietary long-chain n-3 polyunsaturated fatty acids (LCPUFA) on hypertension and cardiac consecutive disorders in spontaneously hypertensive rats (SHR) as compared to Wistar-Kyoto rats (WKY). Rats were fed for 2 months an eicosapentaenoic (EPA)- or docosahexaenoic acid (DHA)-rich diet (240 mg/day) or an n-3 PUFA-free diet. Male SHR (n=6), implanted with cardiovascular telemetry devices, were housed in individual cages for continuous measurements of cardiovascular parameters (blood pressure (BP) and heart rate (HR)) during either activity or rest periods, ECG were recorded during the quiet period.

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Background: Previous work showed that the functional cardiac effect of dietary alpha-linolenic acid (ALA) in rats requires a long feeding period (6 months), although a docosahexaenoic (DHA) acid-supply affects cardiac adrenergic response after 2 months. However, the total cardiac membrane n-3 polyunsaturated fatty acid (PUFA) composition remained unchanged after 2 months. This delay could be due to a specific reorganization of the different subcellular membrane PUFA profiles.

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Oxidized low density lipoprotein (Ox-LDL) is a well-established risk factor in atherosclerosis and lysophosphatidylcholine (LysoPtdCho) is considered to be one of the major atherogenic component of Ox-LDL. The purpose of this work was to investigate the effects of two membrane n-3 long chain polyunsaturated fatty acids (n-3 PUFAs), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) compared to n-6 PUFA, ARA (arachidonic acid), on the activation of endothelial NO synthase (eNOS) by histamine in Ea hy 926 endothelial cells incubated during 24 h in the presence or the absence of LysoPtdCho. DHA (50 muM) produced a ROS induction in cells and aggravated the LysoPtdCho-induced oxidative stress.

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The crossover relationship between cardiometabolic risk, in terms of insulin resistance and vascular dysfunction, and the fatty acid (FA) profile of insulin-sensitive tissues as well as the dietary FA impact has almost never been explored in the same experiment. In this study, the intake of alpha-linolenic acid (ALA) alone and/or with its higher metabolites, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were evaluated in a nonobese, hypertriglyceridemic and insulin-resistant rat model, that exhibits the 2 main characteristics of metabolic syndrome. Wistar rats were fed either a cornstarch and (n-6) PUFA-based diet (C-N6) or a 66% fructose diet over a 10-wk period.

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Long chain polyunsaturated fatty acids (PUFAs) play an important role in cardioprotection. These effects have been largely attributed to membrane docosahexaenoic acid. Conversely, saturated fatty acids trigger apoptosis in cardiomyocytes, with modifications of mitochondrial properties including cardiolipin loss, cytochrome c release and caspase-3 activation.

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This study investigated the influence of an eicosapentaenoic acid (EPA)- or a docosahexaenoic acid (DHA)-supplemented diet on the deleterious effects of lysophosphatidylcholine (LPC) on endothelium-dependent vasorelaxation of Golden Syrian hamster thoracic aorta. In a second step, LPC-modulated phospholipase A(2) (PLA(2))-derived ways of relaxation were investigated. Golden Syrian hamsters were fed for 6 weeks with a control diet or an EPA- or DHA-supplemented diet.

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Hypertriglyceridemia being an independent cardiovascular risk factor, we have compared the potential of sera from asymptomatic hypertriglyceridemic (HTG) type IIb, type IV or normolipidemic (NLP) subjects to promote both fractional cholesterol efflux and cellular cholesterol mass changes using macrophage foam cells. The J774 cells loaded with cholesterol by incubation with acetylated LDL were incubated in the absence or presence of cAMP to upregulate ABCA1 (ATP binding cassette transporter A1) and then incubated for 24h with 1% serum. Compared with NLP, type IV sera exhibited a major increase in ABCA1-dependent efflux while type IIb sera exhibited a moderate but not significant increased ABCA1-mediated efflux.

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The present study was designed to evaluate whether long-term intake of dietary alpha-linolenic acid (ALA), supplied as whole grain-extruded linseed, can increase endogenous production of n-3 long-chain polyunsaturated fatty acids (FAs) in healthy adult rats and influence the heart rate (HR) and adrenergic response in the same way as docosahexaenoic acid (DHA)-rich diets. DHA enrichment was evaluated using FA analysis of tissue phospholipids after 8, 16, 24, and 32 wk of feeding in male Wistar rats randomly assigned to three dietary groups (n = 8 in each group): a reference fat diet (RFD), an ALA-rich (ALA) diet, and a DHA-rich (DHA) diet. At 1 wk before the animals were killed, under anesthesia, HR was measured from ECG recordings during an adrenergic stimulation challenge (n = 8).

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AMP-activated protein kinase (AMPK) plays an important role in controlling energy homeostasis and is envisioned as a promising target to treat metabolic disorders. In the heart, AMPK is involved in short-term regulation and in transcriptional control of proteins involved in energy metabolism. Here, we investigated whether deletion of AMPKalpha2, the main cardiac catalytic isoform, alters mitochondrial function and biogenesis.

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The aim of this study was to evaluate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on NO synthase (eNOS) activation in Ea hy 926 endothelial cells. EPA or DHA (0-80 microM), added to the culture medium during 24h, were dose-dependently incorporated into the cells. In control medium, eNOS activity (evaluated by the citrulline assay) and eNOS phosphorylation on Ser 1177 were correlated.

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We reported previously that glycerol is a substrate for energy production in cardiomyocytes. Increasing glycerol availability results in increased glycerol uptake and its involvement in complex lipid biosynthesis and energy production. This study evaluated the relationship between glycerol supply, energy demand, and intermediary metabolism leading to energy production.

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Although lipids are largely involved in cardiovascular physiopathology, the lipid metabolism in endothelial cells remains largely unknown. Human umbilical vein endothelial cells (HUVECs) were used to investigate the metabolism of complex lipids. The membrane phospholipid homeostasis results from both de novo synthesis and remodelling that ensures the fine tuning of the phospholipid fatty acid composition.

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The present study investigated the ability of trimetazidine (TMZ) to maintain cardiac mitochondrial function during the development of insulin deficiency and hyperinsulinaemia. The anti-ischaemic drug TMZ is known to increase phospholipid synthesis in cardiac membranes and to have a cardioprotective effect. Insulin deficiency was obtained by streptozotocin injection and hyperinsulinaemia was achieved via a fructose diet.

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In the human heart, although all substrates compete for energy production, fatty acids (FA) represent the main substrate for ATP production. In the healthy heart, a balance between FA and carbohydrate utilization ensures that energy supply matches demand. This study was carried out to evaluate, in a model of spontaneously beating neonatal rat cardiomyocytes in culture, the hypothesis that glycerol could play a central role in the metabolic control of the routes involving long chain FAs and may then affect the balance between beta-oxidation and glucose oxidation.

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