Liver X Receptor Regulates Triglyceride Absorption Through Intestinal Down-regulation of Scavenger Receptor Class B, Type 1Briand, O., Touche, V., Colin, S., Brufau, G., Davalos, A., Schonewille, M., Bovenga, F., Carriere, V., de Boer, J. F., Dugardin, C., Riveau, B., Clavey, V., Tailleux, A., Moschetta, A., Lasuncion, M. A., Groen, A. K., Staels, B. & Lestavel, S., Mar-2016, In : Gastroenterology. 150, 3, p. 650-658 9 p.
Research output: Contribution to journal › Article › Academic › peer-review
BACKGROUND & AIMS: Reducing postprandial triglyceridemia may be a promising strategy to lower the risk of cardiovascular disorders associated with obesity and type 2 diabetes. In enterocytes, scavenger receptor class B, type 1 (SR-B1, encoded by SCARB1) mediates lipid-micelle sensing to promote assembly and secretion of chylomicrons. The nuclear receptor subfamily 1, group H, members 2 and 3 (also known as liver X receptors [LXRs]) regulate genes involved in cholesterol and fatty acid metabolism. We aimed to determine whether intestinal LXRs regulate triglyceride absorption. METHODS: C57BL/6J mice were either fed a cholesterol-enriched diet or given synthetic LXR agonists (GW3965 or T0901317). We measured the production of chylomicrons and localized SR-B1 by immunohistochemistry. Mechanisms of postprandial triglyceridemia and SR-B1 regulation were studied in Caco-2/TC7 cells incubated with LXR agonists. RESULTS: In mice and in the Caco-2/TC7 cell line, LXR agonists caused localization of intestinal SR-B1 from apical membranes to intracellular organelles and reduced chylomicron secretion. In Caco-2/TC7 cells, LXR agonists reduced SR-B1-dependent lipidic-micelle-induced Erk phosphorylation. LXR agonists also reduced intracellular trafficking of the apical apolipoprotein B pool toward secretory compartments. LXR reduced levels of SR-B1 in Caco-2/TC7 cells via a post-transcriptional mechanism that involves microRNAs. CONCLUSION: In Caco-2/TC7 cells and mice, intestinal activation of LXR reduces the production of chylomicrons by a mechanism dependent on the apical localization of SR-B1.
|Number of pages||9|
|Publication status||Published - Mar-2016|
- Hypertriglyceridemia, Lipid-Sensing, Fat Absorption, Triglyceride-Rich Lipoproteins, DENSITY-LIPOPROTEIN METABOLISM, POSTPRANDIAL LIPID-METABOLISM, REVERSE CHOLESTEROL TRANSPORT, SR-BI, HDL-CHOLESTEROL, LXR-ALPHA, EXPRESSION, ENTEROCYTES, MICE, GENE