title: Induction of intestinal ATP-binding cassette transporters by a phytosterol-derived liver X receptor agonist.
abstract: The nuclear receptors liver X receptor (LXR) alpha and LXRbeta serve as oxysterol receptors and regulate the expression of genes involved in lipid metabolism. LXR activation induces the expression of ATP-binding cassette (ABC) transporters, such as ABCG5 and ABCG8, which inhibit intestinal absorption of cholesterol and phytosterols. Although several synthetic LXR agonists have been generated, these compounds have limited clinical application, because they cause hypertriglycemia by inducing the expression of lipogenic genes in the liver. We synthesized derivatives of phytosterols and found some of them to act as LXR agonists. Among them, YT-32 [(22E)-ergost-22-ene-1alpha,3beta-diol], which is related to ergosterol and brassicasterol, is the most potent LXR agonist. YT-32 directly bound to LXRalpha and LXRbeta and induced the interaction of LXRalpha with cofactors, such as steroid receptor coactivator-1, as effectively as the natural ligands, 22(R)-hydroxycholesterol and 24(S),25-epoxycholesterol. Although the nonsteroidal synthetic LXR agonist T0901317 induced the expression of intestinal ABC transporters and liver lipogenic genes, oral administration of YT-32 selectively activated intestinal ABC transporters in mice. Unlike T0901317 treatment, YT-32 inhibited intestinal cholesterol absorption without increasing plasma triglyceride levels. The phytosterol-derived LXR agonist YT-32 might selectively modulate intestinal cholesterol metabolism.
authors.affiliation: Graduate School of Medicine and Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Kaneko
authors.forename: Morihiro
authors.initials: M
authors.lastname: Matsuda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yamada
authors.forename: Yoji
authors.initials: Y
authors.lastname: Tachibana
authors.forename: Iichiro
authors.initials: I
authors.lastname: Shimomura
authors.forename: Makoto
authors.initials: M
authors.lastname: Makishima
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology; D001692:Biological Transport; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000378:metabolism; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004875:Ergosterol / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D017930:Genes, Reporter; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D006845:Hydrocarbons, Fluorinated; D006888:Hydroxycholesterols / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008024:Ligands; D008099:Liver / Q000378:metabolism; D000071518:Liver X Receptors; D051379:Mice; D008956:Models, Chemical; D057093:Orphan Nuclear Receptors; D010840:Phytosterols / Q000378:metabolism*; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013449:Sulfonamides; D013997:Time Factors; D014162:Transfection; D005466:Fluorocarbons; D000096926:Benzenesulfonamides
chemical_list: D018528:ATP-Binding Cassette Transporters; D000924:Anticholesteremic Agents; D002784:Cholesterol; D004268:DNA-Binding Proteins; D004875:Ergosterol; D005982:Glutathione Transferase; D006845:Hydrocarbons, Fluorinated; D006888:Hydroxycholesterols; D008024:Ligands; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D010840:Phytosterols; D018160:Receptors, Cytoplasmic and Nuclear; D013449:Sulfonamides; C000605213:NR1H3 protein, human; C000605214:Nr1h3 protein, mouse; C423915:T0901317; D005466:Fluorocarbons; D000096926:Benzenesulfonamides; C478772:ergost-22-ene-1,3-diol; C003585:22-hydroxycholesterol; C028358:24,25-epoxycholesterol