title: Transcellular transport of organic anions across a double-transfected Madin-Darby canine kidney II cell monolayer expressing both human organic anion-transporting polypeptide (OATP2/SLC21A6) and Multidrug resistance-associated protein 2 (MRP2/ABCC2).
abstract: Human organic anion transporting polypeptide 2 (OATP2/SLC21A6) and multidrug resistance-associated protein 2 (MRP2/ABCC2) play important roles in the vectorial transport of organic anions across hepatocytes. In the present study, we have established a double-transfected Madin-Darby canine kidney (MDCK II) cell monolayer, which expresses both OATP2 and MRP2 on basal and apical membranes, respectively. The basal-to-apical transport of 17 beta estradiol 17 beta-d-glucuronide (E(2)17 beta G), pravastatin, and leukotriene C(4) (LTC(4)), which are substrates of OATP2 and MRP2, was significantly higher than that in the opposite direction in the double-transfected cells. Such vectorial transport was also observed for taurolithocholate sulfate, which is transported by rat oatp1 and Mrp2. The K(m) values of E(2)17 beta G and pravastatin for the basal-to-apical flux were 27.9 and 24.3 microm, respectively, which were comparable with those reported for OATP2. Moreover, the MRP2-mediated export of E(2)17 beta G across the apical membrane was not saturated. In contrast, basal-to-apical transport of estrone-3-sulfate and dehydroepiandrosterone sulfate, which are significantly transported by OATP2, but not by MRP2, was not stimulated by MRP2 expression. The double-transfected MDCK II monolayer expressing both OATP2 and MRP2 may be used to analyze the hepatic vectorial transport of organic anions and to screen the transport profiles of new drug candidates.
authors.affiliation: Department of Biopharmaceutics, School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Kousei
authors.initials: K
authors.lastname: Ito
authors.forename: Takaaki
authors.initials: T
authors.lastname: Abe
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000818:Animals; D001692:Biological Transport; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D019314:Dehydroepiandrosterone Sulfate / Q000378:metabolism; D004285:Dogs; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism; D004970:Estrone / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D007668:Kidney; D007700:Kinetics; D027381:Liver-Specific Organic Anion Transporter 1 / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013658:Taurolithocholic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D014162:Transfection
chemical_list: D019314:Dehydroepiandrosterone Sulfate; D004958:Estradiol; D004970:Estrone; D027381:Liver-Specific Organic Anion Transporter 1; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011994:Recombinant Proteins; D013658:Taurolithocholic Acid; C000715087:ABCC2 protein, human; C066776:taurolithocholic acid 3-sulfate; C025483:estradiol-17 beta-glucuronide; C017296:estrone sulfate; C421109:multidrug resistance-associated protein 1