CD36 as a lipid sensor

International audience; CD36 is a multifunctional protein homologous to the class B scavenger receptor SR-B1 mainly found in tissues with a sustained lipid metabolism and in several hematopoieic cells. CD36 is thought to be involved in various physiological and pathological processes like angiogenesis, thrombosis, atherogenesis, Alzheimer's disease or malaria. An additive emerging function for CD36 is a role as a lipid sensor. Location of CD36 and orthologue molecules in plasma membrane of cells in contact with the external environment (e.g. gustatory, intestinal or olfactory epithelia) allows the binding of exogenous-derived ligands including dietary lipids, diglycerides from bacterial wal…

O24 Obésité et perception oro-sensorielle des lipides alimentaires : impact sur la triglycéridémie et le taux de cholécystokinine

P129 L’obésité interfère avec la détection oro-sensorielle des acides gras à longue chaîne chez l’homme

The Lipid-Sensor Candidates CD36 and GPR120 Are Differentially Regulated by Dietary Lipids in Mouse Taste Buds: Impact on Spontaneous Fat Preference

BACKGROUND: Recent studies in rodents and humans suggest that the chemoreception of long-chain fatty acids (LCFA) in oral cavity is involved in the spontaneous preference for fatty foods and might contribute to the obesity risk. CD36 and GPR120 are LCFA receptors identified in rodent taste bud cells. The fact that CD36 or GPR120 gene inactivation leads to a decrease in the preference for lipids raises the question of the respective role(s) played by these gustatory lipid-sensor candidates. METHODOLOGY/PRINCIPAL FINDINGS: Using a combination of biochemical, nutritional and behavioural studies in wild-type, CD36(+/-)and CD36(-/-) mice, it was found that: 1°) CD36 and GPR120 display different …

Is the taste of fat regulated?

Over the last decade, converging data have been accumulated both in rodents and humans, supporting the existence of a sixth taste modality devoted to the perception of dietary lipids. It is well known that the sense of taste is determinant for the food choice and that the overconsumption of highly palatable energy-dense foods contributes to the current obesity epidemic. Thus, an important issue in terms of Public Health is to understand the mechanisms by which the oro-sensory perception of fat is regulated. An overview of our current knowledge in this field of investigations is proposed in this mini-review.

P208: La chute de la détection oro-sensorielle des lipides alimentaires chez la souris obèse a-t-elle une origine inflammatoire ?

Introduction et but de l’etude Nous avons recemment montre qu’une obesite induite chez la souris par un regime riche en acides gras satures perturbe la detection oro-sensorielle des lipides alimentaires. En effet, les souris obeses deviennent incapables de detecter correctement la presence de faibles concentrations de lipides lors de tests de double choix. Une correlation inverse entre masse grasse et seuil de detection orale des lipides a ete trouvee. Ce phenomene, dont l’origine est un dysfonctionnement de la cascade de signalisation CD36 dependante dans la papille gustative caliciforme (CVP), est reversible puisqu’une perte de masse grasse induite par une restriction calorique permet une…

Obesity interferes with the orosensory detection of long-chain fatty acids in humans

Background: The association between the orosensory detection of lipids, preference for fatty foods, and body mass index (BMI; in kg/m 2 ) is controversial in humans. Objective: We explored the oral lipid-sensing system and the orosensory-induced autonomic reflex system in lean and obese subjects. Design: Lean (BMI: 19 to ,25; n = 30) and obese (BMI .30; n = 29) age-matched men were enrolled. Their oral threshold sensitivity to linoleic acid (LA) was determined by using a 3-alternative forced-choice ascending procedure, and their eating habits were established by the analysis of 4 consecutive 24-h food-consumption diaries. The effect of brief oral lipid stimulations on plasma triglyceride [(…

Obesity alters the gustatory perception of lipids in the mouse: plausible involvement of lingual CD36. : Obesity decreases the fat preference

International audience; A relationship between orosensory detection of dietary lipids, regulation of fat intake, and body mass index was recently suggested. However, involved mechanisms are poorly understood. Moreover, whether obesity can directly modulate preference for fatty foods remains unknown. To address this question, exploration of the oral lipid sensing system was undertaken in diet-induced obese (DIO) mice. By using a combination of biochemical, physiological, and behavioral approaches, we found that i) the attraction for lipids is decreased in obese mice, ii) this behavioral change has an orosensory origin, iii) it is reversed in calorie-restricted DIO mice, revealing an inverse …

P073 L’obésité diminue, de manière réversible, la préférence pour les lipides alimentaires chez la souris

International audience; Introduction et but de l’étude. – Au cours des dernières années, il a été suggéré l’existence d’un lien étroit entre la détection oro-sensorielle des lipides alimentaire, la régulation de la prise alimentaire et l’IMC. Toutefois, les mécanismes affectant la sensibilité aux lipides ainsi que l’éventuelle implication directe de l’obésité restent mal connus.

Different effects of pioglitazone and rosiglitazone on lipid metabolism in mouse cultured liver explants.

Background Pioglitazone (PIO) and rosiglitazone (ROSI) are widely used as oral antidiabetic agents for treatment of type 2 diabetes. Although these medications exert similar effects on blood glucose, recent clinical studies indicated that PIO has a more pronounced beneficial effect on lipid parameters than ROSI. In order to get further insight into the lipid effects of both drugs, we tested whether PIO, compared to ROSI, could exert direct effects on lipid liver metabolism in relation with plasma lipids. Methods We performed in vitro studies using mice liver slices incubated 21 h either with ROSI (1 µmol/L) or PIO (7.5 µmol/L). Results We showed that both glitazones slightly reduced HMG-CoA…

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

Role of CD36 in Oral and Postoral Sensing of Lipids

Obesity and associated plethora of diseases constitute a major public health challenge worldwide. The conjunction of profound changes in our lifestyle and a thrifty genetic that evolved in an environment of food scarcity largely explains this epidemic situation. Food abundance promotes our specific appetite for the more palatable food generally rich in lipids. It is noteworthy that this attraction for fatty food is not specific to humans. Rats and mice also spontaneously prefer lipid-rich food in a free-choice situation. Detection of lipids in food requires the presence of specific sensors located in strategic places (e.g., oral cavity, small intestine, brain) whose activation results in a …

Lipid-mediated release of GLP-1 by mouse taste buds from circumvallate papillae: putative involvement of GPR120 and impact on taste sensitivity

Glucagon-like peptide-1 (GLP-1) signaling modulates sweet-taste sensitivity in the mouse. Because circumvallate papillae (CVPs) express both GLP-1 and its receptor, a local regulation has been suggested. However, whether dietary lipids are involved in this regulation, as shown in the gut, is unknown. By using a combination of biochemical, immunohistochemical, and behavioral approaches, the present data i) confirm the role of GLP-1 signaling in the attraction for sucrose, ii) demonstrate that minute quantities of long-chain FAs (LCFAs) reinforce the attraction for sucrose in a GLP-1 receptor-dependent manner, iii) suggest an involvement of the LCFA receptor GPR120 expressed in taste buds in …