Characterization of organic anion transporting polypeptide (OATP) expression and its functional contribution to the uptake of substrates in human hepatocytes
| Autor: | Kenta Yoshida, Yurong Lai, Larissa M. Balogh, Kazuya Maeda, Yuichi Sugiyama, Yi-an Bi, Ayman El-Kattan, Emi Kimoto |
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| Rok vydání: | 2012 |
| Předmět: |
Gene isoform
Substrate Specificities Organic anion transporter 1 Blotting Western Pharmaceutical Science Organic Anion Transporters Organic Anion Transporters Sodium-Independent Sincalide Solute Carrier Organic Anion Transporter Family Member 1B3 Tandem Mass Spectrometry Drug Discovery medicine Humans Pitavastatin Cells Cultured Pravastatin biology Chemistry Liver-Specific Organic Anion Transporter 1 Transporter Organic anion-transporting polypeptide Blot Biochemistry biology.protein Hepatocytes Molecular Medicine medicine.drug Chromatography Liquid |
| Zdroj: | Molecular pharmaceutics. 9(12) |
| ISSN: | 1543-8392 |
| Popis: | Since the substrate specificities of OATP1B1, 1B3, and 2B1 are broad and overlapping, the contribution of each isoform to the overall hepatic uptake is of concern when assessing transporter-mediated drug-drug interactions (DDIs) or genetic polymorphism impact in the clinic. Herein, we quantitatively measured OATP proteins in cryopreserved hepatocytes, sandwich-cultured human hepatocytes (SCHH), and the liver, and examined the relationship with functional uptake of OATP substrates in an effort to identify the OATP isoform(s) contributing to the hepatic uptake of pitavastatin. The modulation of OATP expression in SCHH was found to be lot-dependent. However, OATP protein measurements averaged from 5 lots of SCHH were comparable to that of suspended hepatocytes. All three OATP transporters in suspended hepatocytes and SCHH were significantly lower than those in the liver. In SCHH, the uptake of CCK-8 and pravastatin was found to be associated with the expression of OATP1B3 and OATP1B1, respectively. In suspended hepatocytes, OATP1B1 appeared to show a positive trend with respect to the uptake of pitavastatin, which suggests a selective contribution of OATP1B1 to pitavastatin transport and thus an OATP quantitative protein expression-activity relationship. While the passive diffusion of rosuvastatin in SCHH was consistent across hepatocyte lots, the passive diffusion of pitavastatin varied over a broad range (4-fold) in suspended hepatocytes and was inversely correlated with transporter-mediated uptake, presumably due to cell membrane alterations imparted by cryopreservation. Collectively, SCHH maintains OATP protein expression and membrane integrity and, if feasible when considering research goals, would be considered a superior tool for the characterization of in vitro transport parameters without the complication of membrane leakage. |
| Databáze: | OpenAIRE |
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