Search results for "Lipids"
showing 10 items of 2228 documents
Détection orosensorielle des lipides alimentaires chez la souris : mécanismes impliqués et altérations au cours de l'obésité
2015
Dietary lipids are detected by the gustatory system in rodents and humans. Two candidate lipid-receptors are found in taste buds: CD36, which is involved in the fat taste as shown by studies conducted in our laboratory, and GPR120. Our results show that GPR120 is not directly involved in the gustatory detection of lipids in mice, but could rather be involved in the modulation of the sensitivity for fat. When this gustatory system works properly, food choices can meet the organism’s energy needs. Besides, the pleasure brought by the consumption of palatable foods is satisfied. However, obese people often overconsume energy-dense food. In the central nervous system, perturbations of the rewar…
Lipid and homeostatic alterations in nervous tissues associated with aging and metabolic dysregulations: implication of gut microbiota and autophagy
2020
The retina and the brain are two nervous tissues rich in lipids. Aging and metabolic syndrome (MetS) are associated with functional and physiological alterations of these tissues as well as modifications in the composition of the gut microbiota. The global objective of this thesis work is to understand the lipid and homeostatic alterations in aging and MetS contexts in the retina and the brain. In a first study, we evaluated the impact of the modifications in the composition of the gut microbiota associated with aging on the lipid/fatty acid contents of the liver and the brain (cortex). We showed that colonization of germ-free mice with the gut microbiota of old mice modulated the hepatic e…
Characterization of cholesterol metabolism in an experimental model of glaucoma in rats
2019
International audience; Glaucoma is a neurodegenerative pathology characterized by retinal ganglion cell death. Cholesterol homeostasis disruption has been implicated in several neurodegenerative diseases such as Alzheimer and Huntington. However, its specific role in the retina and association with glaucoma remain unclear. The aim of this study was to characterize the modifications of cholesterol metabolism occurring during an experimental model of glaucoma in rats. Eight-weeks old male rats were subjected to laser photocoagulation of episcleral veins, limbus and trabecular meshwork to elevate intraocular pressure. At a short (3 days) and a long (2 months) time period post-laser, the retin…
Etude des facteurs nutritionnels et métaboliques de la cancérogenèse hépatique chez des patients atteints de cirrhose
2019
Hepatocellular Carcinoma (HCC) is worldwide the 5th most common diagnosed cancer in men and the 7th in women and the 4th cause of cancer death with a median survival between 10 and 11 months. The incidence rate in France is relatively high (7.8/100 000 with 10 624 estimated new cases in 2018). HCC prognosis is very poor due to the difficulty to diagnose it at an early stage. Around 80% of HCC occur in the setting of cirrhosis, mainly caused by alcoholism, chronic infections with HBV and HCV or metabolic syndrome. Cirrhotic patients have a high-risk to develop chronic inflammation or other liver complications that can progress toward cancer. Thus, it is important to identify the risk factors…
Polyunsaturated fatty acids and plasmalogens in diabetics
2013
PurposePlasmalogens are phospholipids characterized by a vinyl ether bond and a preferential esterification of polyunsaturated fatty acids (PUFA). We have previously shown that the lack of plasmalogens leads to retinal hyper-capillarization. We hypothesize that plasmalogens are negative regulators of vascular development, and aimed to check their circulating levels in diabetic patients with a retinopathy. MethodsBlood samples were collected from 88 patients and 14 control subjects. Among diabetics we had 14 patients without diabetic retinopathy (DR), 12 with a mild non proliferative DR, 12 with a moderate non proliferative DR, 22 with a severe non proliferative DR and 24 with a proliferativ…
Implication of 24-S-hydroxycholesterol in Muller glial cell's membrane dynamics in the rat.
2016
Implication of 24-S-hydroxycholesterol in Muller glial cell's membrane dynamics in the rat.. Association-for-Research-in-Vision-and-Ophthalmology (ARVO)
Role of intestinal epithelial CD36 in obesity and endotoxemia driven by lipid absorption
2021
Intestinal dysbiosis, increased permeability and inflammation are the hallmarks in obese patients, highlighting the role of small intestine beyond providing with calories. CD36 is a ubiquitous scavenger receptor that exhibits high binding affinity for long-chain fatty acids and is highly expressed in enterocytes, endothelial and immune cells. Interestingly, CD36-/- mice and humans with CD36 polymorphisms have an impaired synthesis of triglyceride-rich lipoprotein (TRL). To evaluate the role of CD36 expressed by intestinal-epithelial cells (IEC) in obesity, we conducted experiments on male and female mice deleted in CD36 in IEC (ENT-KO) and control mice (ENT-FL), under standard and high-fat …
Cellular metabolic alteration : the voice of monoinsaturated fatty acid as therapeutic target
2010
Stearoyl Co-A desaturase (SCD) is the key enzyme of the metabolism of mono-unsaturated fatty acids (MUFA). Its activity 9 desaturase introduces a double bond cis in position 9 of saturated fatty acids (SFA), induced formation of MUFA. Impaired biosynthesis of MUFA is involved in many diseases such as cancer and cardiovascular disease. Cancer cells have a de novo synthesis of fatty acids increased with an accumulation MUFA. This change in the metabolism of fatty acids is associated with overexpression SCD1 which catalyzes the conversion of saturated fatty acids, monounsaturated fat. Several reports have shown that inhibition of SCD1 leads to blockage of proliferation and induction of apopt…
Postprandial adaptation of intestinal lipid metabolism : role of CD36 and PPAR beta
2011
Postprandial hypertriglyceridemia is an emerging risk factor for cardiovascular diseases and is associated with metabolic syndrome, obesity and insulin resistance. The small intestine participates in the postprandial triglyceridemia since both the size and number of secreted chylomicrons modulate lipoprotein lipase activity (LPL). Chylomicron synthesis is a complex mechanism in which the lipidation of Apolipoprotein B48 (ApoB48) by the Microsomal Triglyceride Transfer Protein (MTP) and the transfer between reticulum and Golgi in which the Liver Fatty Acid Binding Protein (L -FABP) is involved are limiting steps. An intestinal fat-mediated adaptation in postprandial period has been demonstra…
Influence of phytosterols on the structural and dynamic properties of plant plasma membrane
2008
National audience; The complex mixture of sterols, namely phytosterols, found in the plasma membrane (PM) of plant cells is an intriguing characteristic. In the present work, we characterized the sterol composition of tobacco BY-2 cell PM, and we adapted a sterol manipulation method to this plant material. Methyl-b-cyclodextrin was found to induce a drastic reduction of the PM total free sterol content, with a low specificity for the different phytosterols, and without effect on steryl-conjugates. The consequences of phytosterols depletion were investigated by means of fluorescence spectroscopy and biochemical detergent resistant membrane (DRM) fraction purification methods. Data obtained w…