title: Identification of PLTP as an LXR target gene and apoE as an FXR target gene reveals overlapping targets for the two nuclear receptors.
abstract: Affymetrix microarray data and Northern blot assays demonstrated that phospholipid transfer protein (PLTP) was induced 6-fold when either murine or human macrophages were incubated in the presence of ligands for the liver X receptor (LXR) and the retinoid X receptor. Two functional LXR response elements (LXREs) were identified and characterized in the proximal promoter of the human PLTP gene. One LXRE corresponds to a traditional direct repeat separated by 4 bp. However, the second LXRE is novel in that it corresponds to an inverted repeat separated by 1 bp, and is identical to the farnesoid X receptor response element. These studies demonstrate that PLTP is a direct target for activated LXR and farnesoid X receptor (FXR). In addition, apolipoprotein E (apoE), a known LXR target gene in macrophages, was shown to be activated in liver cells by FXR ligands. Taken together, the current data suggest that a small number of genes that currently include PLTP, apoE, and apoC-II, are induced in macrophages by activated LXR and in liver by activated FXR.
authors.affiliation: Departments of Biological Chemistry and Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Puiying A
authors.initials: PA
authors.lastname: Mak
authors.forename: Heidi R
authors.initials: HR
authors.lastname: Kast-Woelbern
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Anisfeld
authors.forename: Peter A
authors.initials: PA
authors.lastname: Edwards
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D000071518:Liver X Receptors; D008264:Macrophages / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D057093:Orphan Nuclear Receptors; D049294:Phospholipid Transfer Proteins; D011401:Promoter Regions, Genetic; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D000099150:Receptor, Farnesoid X-Activated
chemical_list: D001057:Apolipoproteins E; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D000071518:Liver X Receptors; D008565:Membrane Proteins; D057093:Orphan Nuclear Receptors; D049294:Phospholipid Transfer Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D000099150:Receptor, Farnesoid X-Activated