TY - JOUR T1 - Quantitative Expression of Hepatobiliary Transporters and Functional Uptake of Substrates in Hepatic 2D Sandwich-Cultures: A Comparative Evaluation of Upcyte and Primary Human Hepatocytes JF - Drug Metabolism and Disposition JO - Drug Metab Dispos DO - 10.1124/dmd.117.078238 SP - dmd.117.078238 AU - Michelle Schaefer AU - Gaku Morinaga AU - Akiko Matsui AU - Gerhard Schanzle AU - Daniel Bischoff AU - Roderich D Sussmuth Y1 - 2017/01/01 UR - http://dmd.aspetjournals.org/content/early/2017/12/07/dmd.117.078238.abstract N2 - Deficient functional expression of drug transporters incapacitates most hepatic cell lines as reliable tool for evaluating transporter-mediated drug-drug interactions. Recently, genetically-modified cells, referred to as upcyte hepatocytes, have emerged as an expandable, non‑cancerous source of human hepatic cells. Herein, we quantified mRNA and protein levels of key hepatobiliary transporters and assessed associated uptake activity in short- and long-term cultures of upcyte human hepatocytes (UHH), in comparison to cryopreserved primary human hepatocytes (cPHH). Expression of canalicular efflux pumps, such as MDR1/ABCB1, MATE1/SLC47A1 and MRP2/ABCC2 were relatively well preserved in UHH. By contrast, long-term cultivation of UHH in 2D-sandwich-configuration (SCUHH) was required to upregulate OATP1B1/SLCO1B1, OATP2B1/SLCO2B1, NTCP/SLC10A1 and OCT1/SLC22A1 mRNA expression, which correlated well with respective protein abundances. However, mRNA and protein levels of sinusoidal SLC-transporters, except for NTCP and OATP2B1, remained low in SCUHH compared to sandwich-cultured cPHH (SCHH). OCT1- and NTCP-mediated uptake of MPP+ and taurocholate was demonstrated in both hepatic models, whereas active uptake of OATP1B1/1B3-selective marker substrates, paralleled by markedly reduced SLCO1B1/1B3 expression, were not detectable in SCUHH. Uptake studies under Na+-depletion and excess of taurocholate confirmed the presence of functional NTCP protein and indicated that NTCP, apart from OATP2B1, contributed substantially to the overall hepatic uptake of rosuvastatin in SCUHH. In conclusion, our data suggest that SCUHH, despite their limitation for evaluating OATP1B1/1B3-mediated transport processes, retain NTCP-, OATP2B1- and OCT1-transport activities and thus may be considered as tool for elucidating compensatory uptake pathways for OATP1B1/1B3 substrates. ER -