Search results for "Cholestérol"
showing 10 items of 17 documents
Brain Control of Plasma Cholesterol Involves Polysialic Acid Molecules in the Hypothalamus
2017
IF 3.566; International audience; The polysialic acid (PSA) is a large glycan that is added to cell-surface proteins during their post-translational maturation. In the brain, PSA modulates distances between cells and controls the plasticity of the nervous system. In the hypothalamus, PSA is involved in many aspects of energy balance including food intake, osmoregulation, circadian rhythm, and sleep. In this work, we investigated the role of hypothalamic PSA in the regulation of plasma cholesterol levels and distribution. We report that HFD consumption in mice rapidly increased plasma cholesterol, including VLDL, LDL, and HDL-cholesterol. Although plasma VLDL-cholesterol was normalized withi…
7-ketocholesterol and 7β-hydroxycholesterol: in vitro and animal models used to characterize their activities and to identify molecules preventing th…
2020
International audience; Oxysterols are molecules derived by the oxidation of cholesterol and can be formed either by auto-oxidation, enzymatically or by both processes. Among the oxysterols formed by auto-oxidation, 7-ketocholesterol and 7beta-hydroxycholesterol are the main forms generated. These oxysterols, formed endogenously and brought in large quantities by certain foods, have major cytotoxic properties. They are powerful inducers of oxidative stress, inducing dysfunction of organelles (mitochondria, lysosomes and peroxisomes) that can cause cell death. These molecules are often identified in increased amounts in common pathological states such as cardiovascular diseases, certain eye …
Preparation and characterization of extracts argania spinosa and argan oil and evaluation of their neuroprotective effects in vivo and in vitro
2016
من بين الزيوت الطبيعية أثار زيت أركان الكثير من الاهتمام. فقد استخدم زيت الأركان في الطب التقليدي، من قبل نساء البربرللعناية بالجسم و الشعر، و لمنع بعض الأمراض القلب و الأوعية الدموية . يتميز زيت الأركان بوظائفه التي تخص خفض الكوليسترول، مكافحة داء السكري ومكافحة التكاثر في خطوط الخلايا السرطانية البشرية للبروستات. يعتبر زيت اركان غنيا بالأحماض الدهنية غير المشبعة، البوليفينول، التوكوفيرول و الستيرول .هذه المواد تجعله مادة مضادة للأكسدة.يتركز دور مضادات الأكسدة الغذائية في وظيفة الجهاز العصبي وبعض الأمراض المرتبطة بالعمر على فيتامين E الذي يعتبر المكون الرئيسي لزيت أركان . الهدف من هذا العمل هو أولا دراسة كيميائية لنبتة اركان وتقييم القوة المضادة للأكسدة لمقتطفات هذه النبتة مع توصيف شامل لت…
Involvement of Kv3.1 potassium chanels in 7-ketocholesterol, 24S-hydroxycholesterol and C24 : 0-induced lipotoxicity on 158N and BV-2 cells : relatio…
2017
Potassium (K+) is involved in the regulation of cellular excitability, cell cycle regulation, cell viability, neuroprotection and maintenance of microglial and oligodendrocytic functions. Potassium dysfunction, described in several neurodegenerative diseases such as Alzheimer's Disease (AD), multiple sclerosis (MS), Parkinson's disease and Huntington's disease, may be a potential therapeutic target. The underlying toxic mechanisms of these neurodegenerative pathologies involve oxysterols, which are oxidized cholesterol derivatives, and fatty acids including those associated with peroxisomal metabolism. 7-ketocholesterol (7KC), 24S-hydroxycholesterol (24S-OHC) and tetracosanoic acid (C24:0),…
Highlighting the divertsity of cactus populations (Opuntia spp.) in Morocco and modulation of lipid metabolism by natural extracts and phytosterols f…
2015
The objective of this PhD thesis is to characterize the Moroccan germplasm of the cactus Opuntia collected from different regions in Morocco, by studying the phenologic behavior, the genetic features and physicochemical composition, along with the molecules of high therapeutic potential which may have beneficial effects on the central nervous system cells from cactus extracts (fruit, flower, seed, oil, cladodes and spine) and compared to Argan oil. This work has been conducted in fours different laboratories sharing complementary analyses skills at agronomic, biochemistry, molecular levels. Our results are presented in three parts : (i) cactus agronomic characteristics, (ii) purification an…
Altérations mitochondriales et processus inflammatoire dans la déficience en acyl- Coenzyme A oxydase 1 peroxysomale
2012
Acyl-CoA oxidase 1 (ACOX1) is the rate-limiting enzyme of the peroxisomal fatty acid β-oxidation pathway of very-long-chain fatty acid (VLCFAs). In humans, ACOX1 deficiency, also called pseudo-neonatal adrenoleukodystrophy, is an autosomal recessive and a severe form of the peroxisomal β-oxidation deficiency. Patients suffer from severe delayed motor development followed by a progressive neurological regression including progressive hypodensity of cerebral white matter, hepatomegaly and deafness and die during late-infantile period. Elevated plasma and tissues VLCFAs levels are detected in these patients. Mice lacking ACOX1 develop severe microvesicular steatohepatitis with increased intrah…
Regulation of cholesterol metabolism in the retina under experimental conditions associated with glaucoma
2019
Cholesterol is a lipid found in every animal cell and is necessary for its survival. Among its multiple roles in the body, it is a component of cell membranes that is crucial for the maintenance of their structure and fluidity and is thus implicated in the modulation of many signalling pathways. Neurons are especially dependant on cholesterol input since the proper composition of their plasma membrane is required for vesicular exocytosis of neurotransmitters and transduction of the post-synaptic signal. It has been shown that both an excess and a lack of cholesterol is neurotoxic. Moreover, many neurodegenerative diseases, such as Alzheimer’s or Huntington’s disease, have been associated wi…
modifications peroxysomales associées à l'oxyapoptophagie induite par le 7-cétocholestérol et identification de lipides cytoprotecteurs
2020
Oxidative stress is often increased in several diseases such as age-related diseases (cardiovascular diseases, eye diseases (age-related macular degeneration (AMD) and cataracts), neurodegenerative diseases (Alzheimer's disease, multiple sclerosis), chronic inflammatory diseases (chronic inflammatory bowel disease (IBD)) as well as certain rare genetic diseases (Niemann Pick's disease, X-linked adrenoleukodystrophy (X-ALD)). Oxidative stress can oxidize various molecules, in particular the cholesterol present in lipid membranes, and lead to the formation of oxidized cholesterol derivatives: oxysterols. Some of them, such as 7-ketocholesterol (7KC), are toxic and may be the cause of a type o…
Lifelong exposure to low dose xeno-hormones in rats : multi-generational effects of xeno-hormone mixtures on taste preferences, maternal behavior, an…
2012
During the last decade, the issue of health-related endocrine disruptors (ED) has been extended to the toxicity of mixtures. The objective of this study was to define the effects of lifelong exposure to ED mixtures, at low doses defined as "non-harmful" by the authorities. In this aim, the effects of mixtures combining genistein, vinclozolin and bisphenol A, have been investigated in the rat by using an integrative and multi-generational experimental approach which takes into account maternal behavior, feeding behavior and development. Our results show that these mixtures could: a) reduce maternal behavior, b) change taste preferences (sweet, salty), c) affect the development from the in ut…
Exposition continue aux xéno-hormones à faibles doses chez le rat : effets multi-générationnels de mélanges sur les préférences gustatives, le compor…
2012
During the last decade, the issue of health-related endocrine disruptors (ED) has been extended to the toxicity of mixtures. The objective of this study was to define the effects of lifelong exposure to ED mixtures, at low doses defined as "non-harmful" by the authorities. In this aim, the effects of mixtures combining genistein, vinclozolin and bisphenol A, have been investigated in the rat by using an integrative and multi-generational experimental approach which takes into account maternal behavior, feeding behavior and development. Our results show that these mixtures could: a) reduce maternal behavior, b) change taste preferences (sweet, salty), c) affect the development from the in ut…