Comparison of Inducibility of Multidrug Resistance (MDR)1, Multidrug Resistance-Associated Protein (MRP)1, and MRP2 mRNAs by Prototypical Microsomal Enzyme Inducers in Primary Cultures of Human and Cynomolgus Monkey Hepatocytes

Abstract

Multidrug resistance 1 (MDR1, p-glycoprotein (P-gp), ABCB1) was the first human ATP binding cassette (ABC) transporter whose cDNA was cloned and characterized based on its ability to confer a multidrug-resistance phenotype to cancer cells. 1) Multidrug resistance-associated protein 1 (MRP1, ABCC1) and multidrug resistance-associated protein 2 (MRP2, ABCC2) have been identified as multidrug-resistance genes and demonstrated to transport glutathione conjugates of many toxic compounds.2,3) The tissue localization of MDR1 includes the choroid plexus (so-called bloodbrain barrier), adrenal gland, kidney, intestine, and liver; that of MRP1 is ubiquitous (but low in the liver); and that of MRP2 includes the kidney, intestine, and liver. [2][3][4] . Several in vivo studies have demonstrated that the expression of ABC transporters such as MDR1, MRP1, and MRP2 is up-or down-regulated by chemical compounds and nutrients in the rat 5,6) and mouse 7,8) liver. Several in vitro studies using human hepatocytes have demonstrated that the expression of ABC transporters such as MDR1 is up-regulated by microsomal enzyme inducers such as rifampicin (Rif) and dexamethasone (Dex).9,10) Furthermore, we have previously described a method for evaluating the mRNA induction of transporters following exposure to microsomal enzyme inducers and candidate drugs in primary cultures of human and rat hepatocytes.11,12) However, few studies have investigated the evaluation of MDR1, MRP1, and MRP2 mRNA expression in cynomolgus monkeys following exposure to drugs, although cynomolgus monkeys have commonly been employed in studies of drug metabolism and toxicity. Furthermore, evaluation employing cynomolgus monkeys as well as evaluation employing rats has been performed in numerous preclinical studies. In order to ensure that the results of preclinical studies involving evaluation by in vitro methods using primary cultures of hepatocytes are applicable to clinical studies, it is important to evaluate the information obtained by the primary culture of both human and cynomolgus monkey hepatocytes. The present study was therefore conducted to compare the inducibility of MDR1, MRP1, and MRP2 mRNAs following exposure to the prototypical microsomal enzyme inducers Rif, Dex, and omeprazole (Ome) in primary cultures of cryopreserved hepatocytes obtained from humans and cynomolgus monkeys. Research and Development Center, Otsuka Pharmaceutical Factory, Inc.; Japan: b Ina Research Inc.; Nishiminowa, Ina, Japan: c Ichikawa General Hospital; Ichikawa, Japan: and d Laboratory of Health Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University; Tsushima-naka, Okayama 700-8530, Japan. Received June 23, 2008; accepted September 8, 2008; published online September 8, 2008 This study investigated the changes in the mRNA levels of the ATP binding cassette (ABC) transporters multidrug resistance 1 (MDR1), multidrug resistance-associated protein 1 (MRP1), and multidrug resistance-associated protein 2 (MRP2) following ex...

Molecular cloning and tissue distribution of a novel marmoset ABC transporter

“…Marmoset ABCB1 mRNA was induced by omeprazole, phenobarbital and rifampicin (Figure S4). Rifampicin increased ABCB1 mRNA levels in primary human and cynomolgus monkey hepatocytes, while omeprazole slightly increased ABCB1 mRNA levels in cynomolgus monkey hepatocytes (Nishimura et al, ; Sahi et al, ). However, omeprazole‐inducible expression of ABCB1 mRNA was not detected in human hepatocytes, unlike marmoset and cynomolgus monkey hepatocytes (Nishimura et al, ), which might partially indicate the species differences of hepatic ABCB1 inducibility in marmosets, cynomolgus monkeys and humans.…”

Regulation of hepatic ABCC transporters by xenobiotics and in disease states

“…MRP2 protein is induced in a gender-dependent manner (Kauffmann et al, 1998). Similarly, treatment of human and cynomolgus monkey hepatocytes, and human liver slices with omeprazole or rifampicin, increases MRP2 expression (Jigorel et al, 2006; Nishimura et al, 2008; Olinga et al, 2008). In SD rats, treatment with pregnenolone 16a-carbonitrile does not markedly change Mrp2 mRNA levels in liver, compared to controls, while it significantly increases Mrp2 protein levels in a time-dependent manner.…”

“…In both human and cynomolgus monkey hepatocytes, MRP1 mRNA levels are shown to increase by rifampicin or omeprazole treatment and tend to decrease with dexamethasone treatment (Nishimura et al, 2008). …”

“…The induction of Mrp2 protein by dexamethasone produces spatially disproportional changes, with the most prominent increases in perivenous hepatocytes (Micuda et al, 2008). Rat hepatocyte isolation does not affect Mrp2 mRNA levels significantly (Nishimura et al, 2008). Further, treatment with dexamethasone induces Mrp2 expression in rat hepatocytes in culture (Courtois et al, 1999; Kubitz et al, 1999a; Luttringer et al, 2002; Lee et al, 2008) and tends to decrease MRP2 mRNA levels in both human and cynomolgus monkey hepatocytes.…”

“…Further, treatment with dexamethasone induces Mrp2 expression in rat hepatocytes in culture (Courtois et al, 1999; Kubitz et al, 1999a; Luttringer et al, 2002; Lee et al, 2008) and tends to decrease MRP2 mRNA levels in both human and cynomolgus monkey hepatocytes. Cynomolgus monkey hepatocytes appear to be more sensitive in response to treatment than human hepatocytes (Nishimura et al, 2008). In mice, dexamethasone treatment does not change liver Mrp2 mRNA (Wang et al, 2008).…”