Search results for "CD36"

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…

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 …

The study of calcium signaling in lipid gustatory cells in mice

2012

The lipid-binding glycoprotein CD36, expressed by circumvallate papillae (CVP) of the mouse tongue, has been shown to be implicated in oro-gustatory perception of dietary lipids. We demonstrate that linoleic acid (LA) by activating sPLA2, cPLA2 and iPLA2 via CD36, produced arachidonic acid (AA) and lyso-phosphatidylcholine (Lyso-PC) which triggered Ca2+ influx in CD36-positive taste bud cells (TBC), purified from mouse CVP. LA induced the production of Ca2+ influx factor (CIF). CIF, AA and Lyso-PC exerted different actions on the opening of store-operated Ca2+ (SOC) channels, constituted of Orai proteins and regulated by STIM1, a sensor of Ca2+ depletion in the endoplasmic reticulum. We use…

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…

Interaction between 24-hydroxycholesterol, oxidative stress, and amyloid-β in amplifying neuronal damage in Alzheimer’s disease: three partners in cr…

2011

All three cholesterol oxidation products implicated thus far in the pathogenesis of Alzheimer's disease, 7β-hydroxycholesterol, 24-hydroxycholesterol, and 27-hydroxycholesterol, markedly enhance the binding of amyloid-beta (Aβ) to human differentiated neuronal cell lines (SK-N-BE and NT-2) by up-regulating net expression and synthesis of CD36 and β1-integrin receptors. However, only 24-hydroxycholesterol markedly potentiates the pro-apoptotic and pro-necrogenic effects of Aβ(1-42) peptide on these cells: 7β-hydroxycholesterol and 27-hydroxycholesterol, like unoxidized cholesterol, show no potentiating effect. This peculiar behavior of 24-hydroxycholesterol at physiologic concentrations (1 μ…

Mécanisme d’absorption intestinale des acides gras à longue chaîne : rôle émergent du CD36

2012

International audience; Excessive lipid intake, associated with a qualitative imbalance, favors the development of obesity and associated diseases. Among the organs involved in lipid homeostasis, the small intestine remains the most poorly known although it is responsible for the lipid bioavailability and largely contributes to the regulation of postprandial hypertriglyceridemia. The mechanism of long chain fatty acid (LCFA) intestinal absorption is not totally elucidated. The synthesis of recent literature indicates that the intestine is able to adapt its absorption capacity to the fat content of the diet. This adaptation takes place through a fat-coordinated induction of LBP and apolipopr…

CD36 is regulated by dietary lipids in mouse circumvallate papillae. Impact on spontaneous fat preference

2011

CD36 Displays Features of a Lipid-Sensor Involved in Chylomicron Processing in the Rodent Small Intestine

2010

International audience; The membrane glycoprotein CD36 binds nanomolar concentrations of long-chain fatty acids (LCFA) and is highly expressed on the luminal surface of enterocytes. CD36 deficiency reduces chylomicron production through unknown mechanisms.In this report, we provide novel insights into the potential underlying mechanisms. Our in vivo data demonstrated that CD36 gene deletion in mice did not affect LCFA uptake and their subsequent esterification into triglycerides by the intestinal mucosa at micellar LCFA concentrations prevailing in the intestine. In rodents, CD36 protein early disappeared from the luminal side of intestinal villi during the post-prandial period but only whe…

Perception oro-sensorielle des lipides alimentaires et obésité

2016

International audience; The gustation is a dynamic system able to rapid physiological adaptations in response to on-going environmental changes that characterize our feed (rhythm, quality, quantity). Based on the modulation of taste sensitivity thresholds, this homeostatic system contributes to build the feeding behavior by driving the food choices. Therefore, a dysfunction of this regulatory system might impact on dietary habits and thus, ultimately, on health. Consistent with this assumption, recent data report that a diet-induced obesity is associated both with a dysfunction of the oral fat detection system and a preferential consumption of fat-rich diets in rats and mice. In humans, a s…