Blood-Brain Barrier Pharmacoproteomics-Based Reconstruction of the In Vivo Brain Distribution of P-Glycoprotein Substrates in Cynomolgus Monkeys

Abstract

The aim of this study was to investigate whether in vivo drug distribution in brain in monkeys can be reconstructed by integrating four factors: protein expression levels of P-glycoprotein (P-gp)/ multidrug resistance protein 1 at the blood-brain barrier (BBB), in vitro transport activity per P-gp molecule, and unbound drug fractions in plasma and brain. For five P-gp substrates (indinavir, quinidine, loperamide, paclitaxel, and verapamil) and one nonsubstrate (diazepam), in vitro P-gp transport activities were determined by measuring transcellular transport across monolayers of cynomolgus monkey P-gp-transfected LLC-PK1 and parental cells. In vivo P-gp functions at the BBB were reconstructed from in vitro P-gp transport activities and P-gp expression levels in transfected cells and cynomolgus brain microvessels. Brain-to-plasma concentration ratios (K p,brain ) were reconstructed by integrating the reconstructed in vivo P-gp functions with drug unbound fractions in plasma and brain. For all compounds, the reconstructed K p,brain values were within a 3-fold range of observed values, as determined by constant intravenous infusion in adult cynomolgus monkeys. Among four factors, plasma unbound fraction was the most sensitive factor to species differences in K p,brain between monkeys and mice. Unbound brainto-plasma concentration ratios (K p,uu,brain ) were reconstructed as the reciprocal of the reconstructed in vivo P-gp functions, and the reconstructed K p,uu,brain values were within a 3-fold range of in vivo values, which were estimated from observed K p,brain and unbound fractions. This study experimentally demonstrates that brain distributions of P-gp substrates and nonsubstrate can be reconstructed on the basis of pharmacoproteomic concept in monkeys, which serve as a robust model of drug distribution in human brain.

Solute Carrier Family of the Organic Anion-Transporting Polypeptides 1A2– Madin-Darby Canine Kidney II: A Promising In Vitro System to Understand the Role of Organic Anion-Transporting Polypeptide 1A2 in Blood-Brain Barrier Drug Penetration

“…Accurate and robust quantification of the OATP1A2 protein with membrane extracts of highly purified human brain capillaries will help this further. The physiologic expression data would help us to contextualize the current in vitro findings, as has been previously done for P-gp (Uchida et al, 2011a(Uchida et al, , 2014. The data could also shed light on the emerging debate on neuronal (Gao et al, 2014) and more widely accepted brain endothelial localization (Gao et al, 2000;Bronger et al, 2005;Lee et al, 2005;Kalvass et al, 2013).…”

Cynomolgus Monkey as a Clinically Relevant Model to Study Transport Involving Renal Organic Cation Transporters: In Vitro and In Vivo Evaluation

“…Recently, an increasing number of investigators have used the cynomolgus monkey as a model to study the inhibition of drug transporters in vivo (Tahara et al, 2006;Shen et al, 2013Shen et al, , 2015bTakahashi et al, 2013;Uchida et al, 2014;Chu et al, 2015;Karibe et al, 2015). Such a model offers advantages in drug development, when the transporter inhibition potential of a clinical candidate requires more extensive evaluation of changes in victim drug pharmacokinetics and organ toxicity.…”

Imaging the impact of cyclosporin A and dipyridamole on P-glycoprotein (ABCB1) function at the blood-brain barrier: A [11C]-N-desmethyl-loperamide PET study in nonhuman primates

“…This approach has revealed interspecies differences in the overall impact of P-gp at BBB of rodents and primates (Syvänen et al, 2009;Tournier et al, 2012). As opposed to rodents, recent proteomic studies have confirmed that monkeys may serve as a robust animal model of drug distribution in the human brain (Uchida et al, 2014).…”