title: Regulation of tissue-specific expression of renal organic anion transporters by hepatocyte nuclear factor 1 α/β and DNA methylation.
abstract: We have reported previously that the kidney- and liver-specific expression of transporters in mice involves the coordinated regulation by hepatocyte nuclear factor 1 (HNF1) and DNA methylation. The present study was aimed at investigating the role of this cascade in the transcriptional regulation of renal organic anion transporters (OATs) yet to be characterized in human and mouse. Luciferase assays and electrophoretic mobility-shift assays demonstrated that HNF1α/β enhances the promoter activity of OAT4/SLC22A11 via binding to the HNF1 motif located near the transcriptional start site (TSS). DNA methylation profiles of human OAT1, OAT3, OAT4, and urate transporter 1 (URAT1) were determined in human liver and kidney cortex by bisulfite sequencing. Most of the CpG dinucleotides around the TSSs of OAT1 and OAT3 were highly methylated in the liver compared with kidney cortex, being consistent with their tissue specificity, whereas the difference in the DNA methylation status was less remarkable between the two tissues for OAT4 and URAT1. Mouse Oat1 gene also contained CpG dinucleotides hypomethylated in the kidney and hypermethylated in the liver downstream its TSS, whereas two of the seven CpG dinucleotides around the TSS of mouse Oat3 were significantly methylated in the liver compared with the kidney. Taken together, these findings underscored the central role of HNF1α/β in the transcriptional regulation of OATs and highlighted DNA methylation-dependent gene silencing as one of the mechanisms underlying the tissue-specific transactivation by this master regulator.
authors.affiliation: Laboratory of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Li
authors.initials: L
authors.lastname: Jin
authors.forename: Ryota
authors.initials: R
authors.lastname: Kikuchi
authors.forename: Takami
authors.initials: T
authors.lastname: Saji
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000818:Animals; D019175:DNA Methylation; D005786:Gene Expression Regulation; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000502:physiology*; D051539:Hepatocyte Nuclear Factor 1-beta / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D027361:Organic Anion Transporters / Q000235:genetics*; D027701:Organic Cation Transport Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic
chemical_list: C496487:HNF1A protein, human; C496495:HNF1B protein, human; D051538:Hepatocyte Nuclear Factor 1-alpha; D027361:Organic Anion Transporters; D027701:Organic Cation Transport Proteins; C491241:SLC22A12 protein, human; D051539:Hepatocyte Nuclear Factor 1-beta