title: Liver X receptor agonist TO-901317 upregulates SCD1 expression in renal proximal straight tubule.
abstract: Liver X receptors (LXRs), including LXRalpha and LXRbeta, are intracellular sterol sensors that regulate expression of genes controlling fatty acid and cholesterol absorption, excretion, catabolism, and cellular efflux. Because the kidney plays an important role in lipid metabolism and dyslipidemia accelerates renal damage, we investigated the effect of TO-901317, an LXR agonist, on the gene expression profile in mouse kidney. Treatment of C57 Bl/6 mice with TO-901317 (3 mg.kg(-1).day(-1)) for 3 days resulted in 51 transcripts that were significantly regulated in the kidney. Among them, the stearoyl-CoA desaturase-1 (SCD1) was upregulated most dramatically. Northern blot analysis revealed that SCD1 mRNA levels were markedly higher than that in control kidneys. Enhanced SCD1 expression by TO-901317 also resulted in increased fatty acid desaturation in the kidney. In control mice, constitutive renal SCD1 expression was low; however, TO-901317 treatment markedly increased SCD1 expression in the outer stripe of the outer medulla as assessed by both in situ hybridization and immunostain. Double-labeling studies further indicated that SCD1 mRNA was selectively expressed in proximal straight tubules negative for aquaporin-2 and Tamm-Horsfall protein. In vitro studies in cultured murine proximal tubule cells further demonstrated that LXR activation enhanced SCD1 transcription via increased sterol regulatory element binding protein-1. Taken together, these data suggest LXR activation of SCD1 expression may play an important role in regulating lipid metabolism and cell function in renal proximal straight tubules.
authors.affiliation: Division of Nephrology, S-3223 MCN, Vanderbilt Univ. Medical Center, Nashville, TN 37232-2372, USA.
authors.forename: Yahua
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Lihong
authors.initials: L
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Dongming
authors.initials: D
authors.lastname: Su
authors.forename: Wendell J
authors.initials: WJ
authors.lastname: Lu
authors.forename: Mei-Tsuey
authors.initials: MT
authors.lastname: Hwang
authors.forename: Guangrui
authors.initials: G
authors.lastname: Yang
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.forename: Minfen
authors.initials: M
authors.lastname: Wei
authors.forename: Linda
authors.initials: L
authors.lastname: Davis
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Breyer
authors.forename: Youfei
authors.initials: Y
authors.lastname: Guan
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D050171:Dyslipidemias / Q000150:complications / Q000503:physiopathology; D006845:Hydrocarbons, Fluorinated; D007684:Kidney Tubules / Q000502:physiology*; D050356:Lipid Metabolism; D000071518:Liver X Receptors; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger / Q000096:biosynthesis; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors; D013230:Stearoyl-CoA Desaturase / Q000096:biosynthesis*; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*; D015854:Up-Regulation; D005466:Fluorocarbons; D000096926:Benzenesulfonamides
chemical_list: D004268:DNA-Binding Proteins; D006845:Hydrocarbons, Fluorinated; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D013230:Stearoyl-CoA Desaturase; D013449:Sulfonamides; C000605214:Nr1h3 protein, mouse; C423915:T0901317; D005466:Fluorocarbons; D000096926:Benzenesulfonamides; C490333:Scd1 protein, mouse