Risk Factors for Development of Cholestatic Drug-Induced Liver Injury: Inhibition of Hepatic Basolateral Bile Acid Transporters Multidrug Resistance-Associated Proteins 3 and 4

Abstract

Impaired hepatic bile acid export may contribute to development of cholestatic drug-induced liver injury (DILI). The multidrug resistance-associated proteins (MRP) 3 and 4 are postulated to be compensatory hepatic basolateral bile acid efflux transporters when biliary excretion by the bile salt export pump (BSEP) is impaired. BSEP inhibition is a risk factor for cholestatic DILI. This study aimed to characterize the relationship between MRP3, MRP4, and BSEP inhibition and cholestatic potential of drugs. The inhibitory effect of 88 drugs (100 mM) on MRP3-and MRP4-mediated substrate transport was measured in membrane vesicles. Drugs selected for investigation included 50 BSEP non-inhibitors (24 non-cholestatic; 26 cholestatic) and 38 BSEP inhibitors (16 noncholestatic; 22 cholestatic). MRP4 inhibition was associated with an increased risk of cholestatic potential among BSEP non-inhibitors. In this group, for each 1% increase in MRP4 inhibition, the odds of the drug being cholestatic increased by 3.1%. Using an inhibition cutoff of 21%, which predicted a 50% chance of cholestasis, 62% of cholestatic drugs inhibited MRP4 (P < 0.05); in contrast, only 17% of non-cholestatic drugs were MRP4 inhibitors. Among BSEP inhibitors, MRP4 inhibition did not provide additional predictive value of cholestatic potential; almost all BSEP inhibitors were also MRP4 inhibitors. Inclusion of pharmacokinetic predictor variables (e.g., maximal unbound concentration in plasma) in addition to percent MRP4 inhibition in logistic regression models did not improve cholestasis prediction. Association of cholestasis with percent MRP3 inhibition was not statistically significant, regardless of BSEP-inhibition status. Inhibition of MRP4, in addition to BSEP, may be a risk factor for the development of cholestatic DILI.

Tyrosine and aurora kinase inhibitors diminish transport function of multidrug resistance-associated protein (MRP) 4 and breast cancer resistance protein (BCRP)

“…MRP4 transports nucleosides, Phase II conjugation products, and conjugated bile acids [20,29]. Inhibition of MRP4-mediated transport has been associated with an increased risk of cholestatic potential, particularly among compounds that do not inhibit the bile salt export pump (BSEP) [29]. Similarities in the chemical properties of MRP4 inhibitors and BSEP inhibitors have been identified [30].…”

“…To confirm transport based on previously developed assays, transport of [ [29,34]. AMP was replaced with ATP for incubations conducted in the absence of an ATP-regenerating system.…”

“…, and untransfected MDCKII cells were cultured in DMEM supplemented with 10 % FBS as previously described [29,31]. MRP4 or BCRP overexpression was maintained by antibiotic selection with hygromycin B [29].…”

“…MRP4 or BCRP overexpression was maintained by antibiotic selection with hygromycin B [29]. Cells were grown to ~85-95 % confluence before membrane vesicle preparation.…”

“…Similar to MRP3, MRP4 resides on the basolateral membrane of hepatocytes, while BCRP, like MRP2, is localized to the apical membrane with each differentially extruding drugs and metabolites into the systemic circulation and bile, respectively. MRP4 transports nucleosides, Phase II conjugation products, and conjugated bile acids [20,29]. Inhibition of MRP4-mediated transport has been associated with an increased risk of cholestatic potential, particularly among compounds that do not inhibit the bile salt export pump (BSEP) [29].…”