scholarly journals Direct Evidence that Saquinavir Is Transported by Multidrug Resistance-Associated Protein (MRP1) and Canalicular Multispecific Organic Anion Transporter (MRP2)

2002 ◽  
Vol 46 (11) ◽  
pp. 3456-3462 ◽  
Author(s):  
Gregory C. Williams ◽  
Angela Liu ◽  
Gregory Knipp ◽  
Patrick J. Sinko
Keyword(s):  
Multidrug Resistance ◽  
Cell Lines ◽  
Direct Evidence ◽  
Organic Anion ◽  
Lethal Dose ◽  
Organic Anion Transporter ◽  
Cell Monolayers ◽  
Directed Transport ◽  
Anion Transporter ◽  
Efflux Ratio

ABSTRACT To determine if saquinavir mesylate (saquinavir) is a substrate of human multidrug resistance-associated protein 1 (hMRP1 [ABCC1]) or hMRP2 (cMOAT, or ABCC2), MDCKII cells that overexpress either hMRP1 (MDCKII-MRP1) or hMRP2 (MDCKII-MRP2) were used to investigate saquinavir's cytotoxicity and transport in comparison with those of control MDCKII wild-type (MDCKII/wt) cells. Cytotoxicity was assessed with the mitochondrial marker MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium], and saquinavir transport was measured directly through the cell monolayers. GF120918 (an inhibitor of P glycoprotein, but not of the MRP family) and MK-571 (an MRP family inhibitor) were used to delineate the specific contributions of these transporters to saquinavir cytotoxicity and transport. In the presence of GF120918 and increasing saquinavir concentrations, the MDCKII-MRP1 (50% lethal dose [LD50] = 10.5 μM) and MDCKII-MRP2 (LD50 = 27.1 μM) cell lines exhibited statistically greater viability than the MDCKII/wt cells (LD50 = 7.8 μM). Saquinavir efflux was directional, not saturable, and was inhibited by MK-571 (35 and 75 μM) in all cell lines. The ratios of saquinavir (3 μM) basolateral to apical permeability (i.e., efflux ratios) for the MDCKII/wt, MDCKII-MRP1, and MDCKII-MRP2 cell monolayers were 2.6, 1.8, and 6.8, respectively. The MDCKII-MRP1 cells have a significantly reduced saquinavir efflux ratio relative to MDCKII/wt cells, due to basolaterally directed transport by hMRP1 competing with endogenous, apically directed canine MRP2. The MDCKII-MRP2 cells have a significantly increased saquinavir efflux ratio relative to MDCKII/wt cells, due to the additive effects of the apically directed transport by hMRP2 and endogenous MRP2. Collectively, the cytotoxicity and transport results provide direct evidence that saquinavir is transported by MRP1 and MRP2.

scholarly journals Regorafenib Is Transported by the Organic Anion Transporter 1B1 and the Multidrug Resistance Protein 2

2015 ◽  
Vol 38 (4) ◽  
pp. 582-586 ◽  
Author(s):  
Hiroki Ohya ◽  
Yoshihiko Shibayama ◽  
Jiro Ogura ◽  
Katsuya Narumi ◽  
Masaki Kobayashi ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Multidrug Resistance Protein ◽  
Multidrug Resistance Protein 2 ◽  
Anion Transporter ◽  
Resistance Protein

Interaction of immunosuppressive drugs with human organic anion transporter (OAT) 1 and OAT3, and multidrug resistance-associated protein (MRP) 2 and MRP4

2013 ◽  
Vol 162 (6) ◽  
pp. 398-409 ◽  
Author(s):  
Azza A.K. El-Sheikh ◽  
Rick Greupink ◽  
Heleen M. Wortelboer ◽  
Jeroen J.M.W. van den Heuvel ◽  
Marieke Schreurs ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Organic Anion ◽  
Immunosuppressive Drugs ◽  
Organic Anion Transporter ◽  
Anion Transporter

scholarly journals Multiple Drug Transporters Are Involved in Renal Secretion of Entecavir

2016 ◽  
Vol 60 (10) ◽  
pp. 6260-6270 ◽  
Author(s):  
Xi Yang ◽  
Zhiyuan Ma ◽  
Sisi Zhou ◽  
Yayun Weng ◽  
Hongmei Lei ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Organic Cation ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Multiple Drug ◽  
Renal Secretion ◽  
Renal Tubular Cells ◽  
Anion Transporter ◽  
Chronic Hepatitis B Virus ◽  
In Cells

ABSTRACTEntecavir (ETV) is a first-line antiviral agent for the treatment of chronic hepatitis B virus infection. Renal excretion is the major elimination path of ETV, in which tubular secretion plays the key role. However, the secretion mechanism has not been clarified. We speculated that renal transporters mediated the secretion of ETV. Therefore, the aim of our study was to elucidate which transporters contribute to the renal disposition of ETV. Our results revealed that ETV (50 μM) remarkably reduced the accumulation of probe substrates in MDCK cells stably expressing human multidrug and toxin efflux extrusion proteins (hMATE1/2-K), organic cation transporter 2 (hOCT2), and carnitine/organic cation transporters (hOCTNs) and increased the substrate accumulation in cells transfected with multidrug resistance-associated protein 2 (hMRP2) or multidrug resistance protein 1 (hMDR1). Moreover, ETV was proved to be a substrate of the above-described transporters. In transwell studies, the transport of ETV in MDCK-hOCT2-hMATE1 showed a distinct directionality from BL (hOCT2) to AP (hMATE1), and the cellular accumulation of ETV in cells expressing hMATE1 was dramatically lower than that of the mock-treated cells. The accumulation of ETV in mouse primary renal tubular cells was obviously affected by inhibitors of organic anion transporter 1/3 (Oat1/3), Oct2, Octn1/2, and Mrp2. Therefore, the renal uptake of ETV is likely mediated by OAT1/3 and OCT2 while the efflux is mediated by MATEs, MDR1, and MRP2, and OCTN1/2 may participate in both renal secretion and reabsorption.

scholarly journals Acamprosate Is a Substrate of the Human Organic Anion Transporter (OAT) 1 without OAT3 Inhibitory Properties: Implications for Renal Acamprosate Secretion and Drug–Drug Interactions

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 390 ◽  
Author(s):  
Irina E. Antonescu ◽  
Maria Karlgren ◽  
Maria L. Pedersen ◽  
Ivailo Simoff ◽  
Christel A. S. Bergström ◽  
...  
Keyword(s):  
Gene Product ◽  
Cell Lines ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Substrate Uptake ◽  
Anion Transporters ◽  
Anion Transporter ◽  
Km Value ◽  
Clinically Significant ◽  
Uptake Studies

Acamprosate is an anionic drug substance widely used in treating symptoms of alcohol withdrawal. It was recently shown that oral acamprosate absorption is likely due to paracellular transport. In contrast, little is known about the eliminating mechanism clearing acamprosate from the blood in the kidneys, despite the fact that studies have shown renal secretion of acamprosate. The hypothesis of the present study was therefore that renal organic anion transporters (OATs) facilitate the renal excretion of acamprosate in humans. The aim of the present study was to establish and apply OAT1 (gene product of SLC22A6) and OAT3 (gene product of SLC22A8) expressing cell lines to investigate whether acamprosate is a substrate or inhibitor of OAT1 and/or OAT3. The studies were performed in HEK293-Flp-In cells stably transfected with SLC22A6 or SLC22A8. Protein and functional data showed that the established cell lines are useful for studying OAT1- and OAT3-mediated transport in bi-laboratory studies. Acamprosate inhibited OAT1-mediated p-aminohippuric acid (PAH) uptake but did not inhibit substrate uptake via OAT3 expressing cells, neither when applied concomitantly nor after a 3 h preincubation with acamprosate. The uptake of PAH via OAT1 was inhibited in a competitive manner by acamprosate and cellular uptake studies showed that acamprosate is a substrate for OAT1 with a Km-value of approximately 700 µM. Probenecid inhibited OAT1-mediated acamprosate uptake with a Ki-value of approximately 13 µM, which may translate into an estimated clinically significant DDI index. In conclusion, acamprosate was identified as a substrate of OAT1 but not OAT3.

Estradiol 17 beta-D-glucuronide is a high-affinity substrate for oatp organic anion transporter

1996 ◽  
Vol 270 (2) ◽  
pp. F326-F331 ◽  
Author(s):  
N. Kanai ◽  
R. Lu ◽  
Y. Bao ◽  
A. W. Wolkoff ◽  
M. Vore ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Organic Anion ◽  
Strong Acid ◽  
Organic Anion Transporter ◽  
Cell Monolayers ◽  
Organic Anion Transporting Polypeptide ◽  
Anion Transporter ◽  
Control Plasmid ◽  
Steroid Conjugates

Although substantial evidence indicates that estradiol-17 beta (E2) is conjugated to the glucuronide in the kidney and then excreted by a direct tubular secretory route and that the liver transports E2 glucuronides via carrier-mediated mechanisms, the transporters involved in these processes have not been identified. The so-called "organic anion-transporting polypeptide" (i.e., oatp) has a number of known substrates, including bromosulfophthalein (BSP) and taurocholic acid (TCA) (E. Jacquemin, B. Hagenbuch, B. Stieger, A. W. Wolkoff, and P. J. Meier. Proc. Natl. Acad. Sci. USA 91: 133-137, 1994). In a companion study, we determined that steroid hormones represent a class of hormones that interact strongly with oatp when the latter is transiently expressed in vitro. Here, we studied more extensively steroids and steroid anion conjugates as candidate oatp substrates. In HeLa cell monolayers transfected with a full-length oatp cDNA, [3H]estradiol 17 beta-D-glucuronide ([3H]E2-17G) was transported with a signal-to-noise ratio of 15:1 over that of monolayers transfected with a control plasmid. The affinity of oatp for [3H]E2-17G was significantly higher than that for TCA (K(m) of 3 microM vs. 27 microM, respectively). In contrast to E2-17G, unconjugated estradiol (E2) was not significantly transported by oatp. Several unconjugated steroids and anionic steroid conjugates were tested for their ability to compete with tracer E2-17G for oatp-mediated transport. Conjugation at the 17 or 3 position with the anion of a strong acid (sulfate) resulted in a greater degree of inhibition of tracer E2-17G transport than did conjugation at the 17 or 3 position with an uncharged group (acetate), suggesting that the strength of the negative charge at these positions is an important determinant of the affinity of a given steroid conjugate for oatp. We conclude that the preferred substrates for oatp are steroids with a strong 17- or 3-position anionic group. Since steroid sulfotransferases and glucuronosyltransferases are expressed in the proximal tubule, as is oatp, the transporter may serve as an apical exit pathway for steroids following their conjugation within the tubule cell.

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