Search results for "Cholesterol"
showing 10 items of 1211 documents
Localization and interactions of melatonin in dry cholesterol/lecithin mixed reversed micelles used as cell membrane models
2005
The state of melatonin confined in dry cholesterol/lecithin mixed reversed micelles dispersed in CCl4 was investigated using 1H-NMR and FT-IR spectroscopies as a function of the melatonin to lecithin molar ratio (R(MLT)) and of the cholesterol to lecithin molar ratio (R(CHL)). An analysis of experimental results leads to the hypothesis that, independent of R(MLT) and as a consequence of anisotropic melatonin/lecithin, melatonin/cholesterol and cholesterol/lecithin interactions, melatonin is totally solubilized in reversed micelles. Melatonin is mainly located in and oriented in the nanodomain constituted by the hydrophilic groups of cholesterol and lecithin. A competition of melatonin and c…
Mechanisms involved in lipid accumulation and apoptosis induced by 1-nitropyrene in Hepa1c1c7 cells
2011
International audience; 1-Nitropyrene (1-NP) is a nitro-polycyclic aromatic hydrocarbon (nitro-PAH) present in diesel exhaust and bound to particular matter in urban air. We show that 1-NP and the referent PAH benzo(a)pyrene (BP) induce apoptosis and a lipid accumulation dependent on cytochrome P450 1A1-metabolites in mouse hepatoma cells, whereas 1-amino-pyrene had no effect. The caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-fmk), inhibits 1-NP-induced apoptosis, but failed to alter 1-NP-triggered lipid accumulation determined by Nile red staining. We further show that cholesterol and fatty acid contents are modified after nitro-PAH exposure and that 1…
Menopause modulates the circulating metabolome: evidence from a prospective cohort study
2022
Abstract Aims We studied the changes in the circulating metabolome and their relation to the menopausal hormonal shift in 17β-oestradiol and follicle-stimulating hormone levels among women transitioning from perimenopause to early postmenopause. Methods and results We analysed longitudinal data from 218 Finnish women, 35 of whom started menopausal hormone therapy during the study. The menopausal transition was monitored with menstrual diaries and serum hormone measurements. The median follow-up was 14 months (interquartile range: 8–20). Serum metabolites were quantified with targeted nuclear magnetic resonance metabolomics. The model results were adjusted for age, follow-up duration, educat…
Chemokine axes and inflammatory status in Metabolic Syndrome. Effect of PCSK9 inhibitors in the systemic inflammation associated to Familial Hypercho…
2019
Metabolic syndrome (MS) is a metabolic disorder characterized by a cluster of cardiovascular risk factors and its prevalence remains increasing in Western world. It is associated to low-grade systemic inflammation, a key driver of premature atherosclerosis and the major cause of cardiovascular disease (CVD). Given that CXCL16/CXCR6, CX3CL1/CX3CR1 and CCL2/CCR2 axes have been implicated in the development of CVD, we investigated the role of these axes in leukocyte adhesion to the dysfunctional arterial endothelium in a MS model. We also performed a comprehensive analysis of different cellular and soluble immune players in patients with MS. When compared with the controls, MS patients present…
Translational Research for Improving the Care of Familial Hypercholesterolemia: The “Ten Countries Study” and Beyond
2016
Familial hypercholesterolemia (FH) is the most common and serious form of inherited hyperlipidaemia. Dominantly inherited with high penetrance, untreated FH leads to premature death from coronary artery disease due to accelerated atherosclerosis from birth. Despite its importance, there is still a major shortfall in awareness, detection and treatment of FH worldwide. International models of care for FH have recently been published, but their effective implementation requires the garnering of more knowledge about the condition. The “Ten Countries Study” aims to investigate diagnostic, epidemiological and service aspects, as well as physician practices and patient experiences of FH in several…
Mixtures of lecithin with polymerizable derivatives of cholesterol. A monolayer film balance study.
1986
One of the best investigated binary lipid mixtures is the lecithin-cholesterol system. We show here that it is possible to modify the cholesterol in such a way that it can be polymerized without changing its behaviour in mixtures with lecithin. The polymerizable derivatives exhibit a very similar phase diagram in the mixture with dipalmitoyl-phosphatidylcholine as the cholesterol itself. This is demonstrated by filmbalance measurements.
24S-hydroxycholesterol and cholesterol-24S-hydroxylase (CYP46A1) in the retina: from cholesterol homeostasis to pathophysiology of glaucoma.
2011
http://www.sciencedirect.com/; International audience; Free cholesterol is the predominant form of cholesterol in the neural retina. The vertebrate neural retina exhibits its own capacity to synthesize cholesterol and meets its demand also by taking it from the circulation. Defects in cholesterol synthesis and trafficking in the neural retina has detrimental consequences on its structure and function, highlighting the crucial importance of maintaining cholesterol homeostasis in the retina. Our purpose was to give a review on the functioning of the retina, the role of cholesterol and cholesterol metabolism therein, with special emphasis on cholesterol-24S-hydroxylase (CYP46A1). Similar to th…
In vivo consequences of cholesterol-24s-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina
2011
Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60mg/kg), minocycline (22mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatography-mass spectrometry. T…
Separating the Mechanism-Based and Off-Target Actions of Cholesteryl Ester Transfer Protein Inhibitors With CETP Gene Polymorphisms
2010
Background— Cholesteryl ester transfer protein (CETP) inhibitors raise high-density lipoprotein (HDL) cholesterol, but torcetrapib, the first-in-class inhibitor tested in a large outcome trial, caused an unexpected blood pressure elevation and increased cardiovascular events. Whether the hypertensive effect resulted from CETP inhibition or an off-target action of torcetrapib has been debated. We hypothesized that common single-nucleotide polymorphisms in the CETP gene could help distinguish mechanism-based from off-target actions of CETP inhibitors to inform on the validity of CETP as a therapeutic target. Methods and Results— We compared the effect of CETP single-nucleotide polymorphisms …
Dysfunctional High-Density Lipoproteins Are Associated With a Greater Incidence of Acute Coronary Syndrome in a Population at High Cardiovascular Risk
2020
Background: Studies have failed to establish a clear link between high-density lipoprotein (HDL) cholesterol and cardiovascular disease, leading to the hypothesis that the atheroprotective role of HDL lies in its biological activity rather than in its cholesterol content. However, to date, the association between HDL functional characteristics and acute coronary syndrome has not been investigated comprehensively. Methods: We conducted a case-control study nested within the PREDIMED (Prevención con Dieta Mediterránea) cohort, originally a randomized trial in which participants followed a Mediterranean or low-fat diet. Incident acute coronary syndrome cases (N=167) were individually matched …