title: Regulation of the angiopoietin-like protein 3 gene by LXR.
abstract: Angiopoietins are members of the vascular endothelial growth factor family. One family member, angiopoietin-like protein 3 (Angptl3), was recently shown to be predominantly expressed in the liver and to play an important role in regulating lipid metabolism. In this study, we show that the Angptl3 gene is a direct target of the liver X receptor (LXR). Mice fed a high cholesterol diet exhibited a significant increase in Angptl3 expression in the liver. Oral administration to mice of T0901317, a synthetic LXR-selective agonist, increases levels of plasma lipids and Angptl3 mRNA in the liver. Treatment of HepG2 cells with LXR selective agonists led to a dose-dependent increase of Angptl3 mRNA. Analysis of the DNA sequence just 5' of the Angptl3 transcriptional start site revealed the presence of several potential transcription factor binding sites, including that for LXR. When transfected into HepG2 cells, the promoter activity of Angptl3 was significantly induced by LXR- or retinoid X receptor-selective agonists. Mutation of the predicted LXR binding site (DR4 element) completely abolished the LXR agonist-mediated activation of the promoter. Together, these studies show that Angptl3 is transcriptionally regulated by LXR, and reveals a novel mechanism by which LXR may regulate lipid metabolism.
authors.affiliation: Department of Atherosclerosis, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Kaplan
authors.forename: Theresa
authors.initials: T
authors.lastname: Zhang
authors.forename: Melba
authors.initials: M
authors.lastname: Hernandez
authors.forename: Frank Xiaodong
authors.initials: FX
authors.lastname: Gan
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Wright
authors.forename: M Gerard
authors.initials: MG
authors.lastname: Waters
authors.forename: Tian-Quan
authors.initials: TQ
authors.lastname: Cai
mesh_terms: D000284:Administration, Oral; D000091303:Angiopoietin-Like Protein 3; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins; D000818:Animals; D001483:Base Sequence; D002784:Cholesterol / Q000008:administration & dosage / Q000494:pharmacology; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D000071518:Liver X Receptors; D051379:Mice; D008969:Molecular Sequence Data; D057093:Orphan Nuclear Receptors; D011401:Promoter Regions, Genetic / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017385:Sequence Homology; D014407:Tumor Cells, Cultured
chemical_list: D000091303:Angiopoietin-Like Protein 3; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins; C404495:Angptl3 protein, mouse; D004268:DNA-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D002784:Cholesterol