title: Effects of quercetin and quercetin 3-glucuronide on the expression of bone sialoprotein gene.
abstract: Quercetin is a typical flavonol-type flavonoid and is present in a variety of vegetables, and their antioxidant effect implies their possible role in the prevention of oxidative stress related chronic diseases. Bone sialoprotein (BSP) is a noncollagenous protein of the extracellular matrix in the mineralized connective tissues that has been implicated in the nucleation of hydroxyapatite crystals. Previously, we reported that isoflavone (genistein) activated BSP gene transcription is mediated through an inverted CCAAT box in the proximal BSP gene promoter. The present study investigates the regulation of BSP transcription in a rat osteoblast-like cell line, ROS 17/2.8 cells, by quercetin and its conjugated metabolite quercetin 3-glucuronide. Quercetin and quercetin 3-glucuronide (5 microM) increased the BSP mRNA levels at 12 h and quercetin upregulated the Cbfa1/Runx2 mRNA expression at 12 h. From transient transfection assays using various sized BSP promoter-luciferase constructs, quercetin increased the luciferase activity of the construct (pLUC3), including the promoter sequence nucleotides -116 to -43. Transcriptional stimulations by quercetin were almost completely abrogated in the constructs that included 2 bp mutations in the inverted CCAAT and FRE elements whereas the CCAAT-protein complex did not change after stimulation by quercetin according to gel shift assays. Quercetin increased the nuclear protein binding to the FRE and 3'-FRE. These data suggest that quercetin and quercetin 3-glucuronide increased the BSP mRNA expression, and that the inverted CCAAT and FRE elements in the promoter of the BSP gene are required for quercetin induced BSP transcription.
authors.affiliation: Department of Periodontology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
authors.forename: Dong-Soon
authors.initials: DS
authors.lastname: Kim
authors.forename: Hideki
authors.initials: H
authors.lastname: Takai
authors.forename: Masato
authors.initials: M
authors.lastname: Arai
authors.forename: Shouta
authors.initials: S
authors.lastname: Araki
authors.forename: Masaru
authors.initials: M
authors.lastname: Mezawa
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Kawai
authors.forename: Kaeko
authors.initials: K
authors.lastname: Murota
authors.forename: Junji
authors.initials: J
authors.lastname: Terao
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D024202:Electrophoretic Mobility Shift Assay; D015870:Gene Expression / Q000187:drug effects*; D058574:Integrin-Binding Sialoprotein; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012795:Sialoglycoproteins / Q000235:genetics*
chemical_list: C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D009841:Oligonucleotides; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C443401:quercetin 3-O-glucuronide; D011794:Quercetin; D008156:Luciferases