College of Pharmacy, Department of Pharmacology & Toxicology (S.R.M., N.J.C.), and College of Medicine, Department of Physiology (S.H.W.), University of Arizona, Tucson, Arizona; and Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina (T.R.L., K.M.Z., S.E.).
College of Pharmacy, Department of Pharmacology & Toxicology (S.R.M., N.J.C.), and College of Medicine, Department of Physiology (S.H.W.), University of Arizona, Tucson, Arizona; and Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina (T.R.L., K.M.Z., S.E.)
Drug Metab Dispos. 2021 Jul;49(7):479-489. doi: 10.1124/dmd.121.000423. Epub 2021 May 12.
Equilibrativenucleoside transporters (ENTs) participate in the pharmacokinetics and disposition of nucleoside analog drugs. Understanding drug interactions with the ENTs may inform and facilitate the development of new drugs, including chemotherapeutics and antivirals that require access to sanctuary sites such as the male genital tract. This study created three-dimensional pharmacophores for ENT1 and ENT2 substrates and inhibitors using K and IC data curated from the literature. Substrate pharmacophores for ENT1 and ENT2 are distinct, with partial overlap of hydrogen bond donors, whereas the inhibitor pharmacophores predominantly feature hydrogen bond acceptors. Mizoribine and ribavirin mapped to the ENT1 substrate pharmacophore and proved to be substrates of the ENTs. The presence of the ENT-specific inhibitor 6--[(4-nitrophenyl)methyl]-6-thioinosine (NBMPR) decreased mizoribine accumulation in ENT1 and ENT2 cells (ENT1, ∼70% decrease, = 0.0046; ENT2, ∼50% decrease, = 0.0012). NBMPR also decreased ribavirin accumulation in ENT1 and ENT2 cells (ENT1: ∼50% decrease, = 0.0498; ENT2: ∼30% decrease, = 0.0125). Darunavir mapped to the ENT1 inhibitor pharmacophore and NBMPR did not significantly influence darunavir accumulation in either ENT1 or ENT2 cells (ENT1: = 0.28; ENT2: = 0.53), indicating that darunavir's interaction with the ENTs is limited to inhibition. These computational and in vitro models can inform compound selection in the drug discovery and development process, thereby reducing time and expense of identification and optimization of ENT-interacting compounds. SIGNIFICANCE STATEMENT: This study developed computational models of human equilibrative nucleoside transporters (ENTs) to predict drug interactions and validated these models with two compounds in vitro. Identification and prediction of ENT1 and ENT2 substrates allows for the determination of drugs that can penetrate tissues expressing these transporters.
平衡核苷转运体（ENTs）参与核苷类似物药物的药代动力学和分布。了解药物与 ENT 的相互作用可能为新药物的开发提供信息和便利，包括需要进入避难所部位（如男性生殖道）的化疗药物和抗病毒药物。本研究使用文献中 curated 的 K 和 IC 数据为 ENT1 和 ENT2 底物和抑制剂创建了三维药效团。ENT1 和 ENT2 的底物药效团是不同的，有部分氢键供体重叠，而抑制剂药效团主要为氢键受体。 Mizoribine 和 ribavirin 映射到 ENT1 底物药效团，被证明是 ENT 的底物。ENT 特异性抑制剂 6--[(4-硝基苯)甲基]-6-硫代肌苷（NBMPR）的存在降低了 ENT1 和 ENT2 细胞中 Mizoribine 的积累（ENT1，约 70%降低， = 0.0046；ENT2，约 50%降低， = 0.0012）。NBMPR 还降低了 ENT1 和 ENT2 细胞中 ribavirin 的积累（ENT1：约 50%降低， = 0.0498；ENT2：约 30%降低， = 0.0125）。Darunavir 映射到 ENT1 抑制剂药效团，NBMPR 对 ENT1 或 ENT2 细胞中 darunavir 的积累没有显著影响（ENT1： = 0.28；ENT2： = 0.53），表明 darunavir 与 ENT 的相互作用仅限于抑制。这些计算和体外模型可以为药物发现和开发过程中的化合物选择提供信息，从而减少鉴定和优化与 ENT 相互作用的化合物的时间和费用。 意义陈述：本研究开发了人平衡核苷转运体（ENTs）的计算模型，以预测药物相互作用，并通过两种化合物在体外验证了这些模型。ENT1 和 ENT2 底物的鉴定和预测允许确定可以穿透表达这些转运体的组织的药物。
