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Abstract：
Implementing the 3R initiative to reduce animal experiments in brain penetration prediction for CNS-targeting drugs requires more predictive in vitro and in silico models. However, animal studies are still indispensable to obtaining brain concentration and determining the prediction performance of in vitro models. To reveal species differences and provide reliable data for IVIVE, in vitro models are required. Systems overexpressing MDR1 and BCRP are widely used to predict BBB penetration, highlighting the impact of the in vitro system on predictive performance. In this study, endogenous Abcb1 knock-out MDCKII cells overexpressing MDR1 of human, mouse, rat or cynomolgus monkey origin were used. Good correlations between ERs of 83 drugs determined in each cell line suggest limited species specificities. All cell lines differentiated CNS-penetrating compounds based on ERs with high efficiency and sensitivity. The correlation between in vivo and predicted Kp,uu,brain was the highest using total ER of human MDR1 and BCRP and optimized scaling factors. MDR1 interactors were tested on all MDR1 orthologs using digoxin and quinidine as substrates. We found several examples of inhibition dependent on either substrate or transporter abundance. In summary, this assay system has the potential for early-stage brain penetration screening. IC50 comparison between orthologs is complex; correlation with transporter abundance data is not necessarily proportional and requires the understanding of modes of transporter inhibition.
摘要：
实施3R计划以减少中枢神经系统靶向药物的脑渗透预测中的动物实验需要更多的体外和计算机模型预测。然而,动物研究对于获得脑浓度和确定体外模型的预测性能仍然是必不可少的。为了揭示物种差异并为IVIVE提供可靠的数据，需要体外模型。过表达MDR1和BCRP的系统被广泛用于预测BBB渗透，强调体外系统对预测性能的影响。在这项研究中,内源性Abcb1敲除过表达人MDR1的MDCKII细胞，鼠标,使用大鼠或食蟹猴来源。在每个细胞系中确定的83种药物的ER之间的良好相关性表明有限的物种特异性。所有细胞系都以高效率和高灵敏度为基础分化CNS穿透化合物。体内与预测的Kp之间的相关性，uu,使用人类MDR1和BCRP的总ER和优化的比例因子，大脑最高。使用地高辛和奎尼丁作为底物对所有MDR1直向同源物测试MDR1相互作用物。我们发现了几个依赖于底物或转运蛋白丰度的抑制实例。总之,该检测系统具有早期脑渗透筛查的潜力.直向同源物之间的IC50比较是复杂的；与转运蛋白丰度数据的相关性不一定成比例，需要了解转运蛋白抑制的模式。
