Identification of new LAT-1 transporter substrates for drug delivery

用于药物输送的新型 LAT-1 转运蛋白底物的鉴定

• 批准号: 9377441
• 负责人: Allen Thomas
• 金额: $ 39.91万
• 依托单位: UNIVERSITY OF NEBRASKA KEARNEY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-18 至 2022-03-17
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9377441
• 关键词: Active Biological Transport; Alzheimer' s Disease; Amino Acid Transporter; Amino Acids; Antineoplastic Agents; Binding; Binding Sites; Biological; Biological Assay; Biology; Blood - brain barrier anatomy; Brain; Brain Diseases; Carboxylic Acids; Carrier Proteins; Cells; Central Nervous System Agents; Chemicals; Computer Simulation; Data; Development; Disease; Drug Delivery Systems; Drug Design; Drug Industry; Drug Kinetics; Drug Targeting; Drug Transport; Drug vehicle; Glucose; Hormones; Knowledge; Legal patent; Levodopa; Link; Literature; Malignant Neoplasms; Malignant neoplasm of brain; Mass Spectrum Analysis; Melphalan; Modeling; Neuraxis; Neutral Amino Acids; Organic Chemistry; Parkinson Disease; Peer Review; Pharmaceutical Preparations; Phenylalanine; Prodrugs; Proteins; Publications; Research; Role; Route; SN-38; Scientist; Structure; Structure-Activity Relationship; Surface; Techniques; Testing; Thyroid Hormones; Time; Tissues; Topoisomerase-I Inhibitor; Work; analog; base; beta-site APP cleaving enzyme 1; cancer cell; cancer clinical trial; cancer type; chemical property; chemical substitution; clinical toxicology; cost; design; experience; experimental study; gabapentin; improved; inhibitor/antagonist; irinotecan; mimetics; novel; pre-clinical; predictive modeling; prevent; scaffold; targeted agent; targeted delivery; tumor; uptake

The blood-brain barrier (BBB) prevents entry of most drug molecules into the brain, an obstacle which adds time and cost to the discovery and development of central nervous system (CNS) drugs. The BBB possesses transporter proteins that allow biological molecules including amino acids, glucose, and hormones to cross as needed. One of these transporter proteins, the L-type amino acid transporter (LAT-1) transports specific amino acids (e.g. phenylalanine) as well as compounds that resemble them (e.g. the drug L-DOPA). This transporter offers a potential route for targeted drug delivery to the brain; moreover, it has been demonstrated that drugs chemically linked to amino acids can cross the BBB via LAT-1. It is known that some molecules are transported (substrates), while others only bind to the transporter surface (inhibitors); however, the structural requirements for either type of activity is poorly understood. We propose mapping the structure-activity relationship (SAR) for molecules that interact with LAT-1 with the aspiration of making this transporter a practical and widely used vehicle for drug delivery. Our approach involves using a computational model of the LAT-1 binding site to guide the synthesis of compounds similar in structure to natural amino acids but with unique chemical properties that could be used to design improved drug delivery agents. Our specific aims are three-fold. First, we will synthesize amino acids chemically substituted with groups that our model predicts will form beneficial interactions with the transporter. Second, we will use cell-based assays to test these compounds. To determine whether they are transported, we will use cis-inhibition and trans-stimulation cell assays which have successfully identified previously unknown substrates. SAR from these experiments will be used to refine our computational model in order to generate hypotheses to guide further substrate optimization. The intracellular concentration of selected compounds will be analyzed by LC-MS/MS to verify our hypothesis that LAT-1 activity increases cell uptake. A third aim of this project will involve the synthesis and testing of amino acid prodrugs of a topoisomerase I inhibitor for cancer (SN-38) to assess whether the SAR derived from optimization of LAT-1 substrates in specific aims 1 and 2 can be applied to improve prodrug cellular uptake. Additionally, the effect of the linker joining SN-38 and the amino acid promoiety, which may have a significant impact on prodrug pharmacokinetics and efficacy, will be examined. This project has broad applications for treating many different diseases both in the brain and other tissues where LAT-1 is heavily expressed, including cancer.

血脑屏障（BBB）防止大多数药物分子进入大脑，这是增加时间的障碍 以及中枢神经系统（CNS）药物的发现和开发的成本。 BBB拥有 允许包括氨基酸，葡萄糖和激素在内的生物分子的转运蛋白越过 需要。这些转运蛋白之一，L型氨基酸转运蛋白（LAT-1）传递特定的氨基 酸（例如苯丙氨酸）以及类似于它们的化合物（例如药物L-DOPA）。这个转运蛋白 为靶向药物传递到大脑提供了潜在的途径；而且，已经证明了药物 与氨基酸的化学联系可以通过LAT-1越过BBB。众所周知，某些分子是运输的 （底物），而其他人仅与转运蛋白表面（抑制剂）结合；但是，结构要求 对于任何一种类型的活动，人们都了解得很糟糕。我们建议映射结构活性关系（SAR） 与LAT-1相互作用的分子和使该转运蛋白成为实用且广泛使用的分子 吸毒的车辆。我们的方法涉及使用LAT-1结合位点的计算模型指导 化合物在结构上的合成与天然氨基酸相似，但具有独特的化学特性 可用于设计改进的药物输送剂。我们的具体目标是三倍。首先，我们将合成 我们的模型预测的基团化学取代的氨基酸将形成有益的相互作用 转运蛋白。其次，我们将使用基于细胞的测定测试这些化合物。确定它们是否是 运输，我们将使用已成功鉴定的CIS抑制和反刺激细胞测定 以前未知的底物。这些实验中的SAR将用于完善我们的计算模型 为了生成假设以指导进一步的底物优化。选定的细胞内浓度 LC-MS/MS将对化合物进行分析，以验证我们的LAT-1活性增加细胞摄取的假设。一个 该项目的第三目将涉及拓扑异构酶I抑制剂的氨基酸前药的合成和测试 对于癌症（SN-38），可以评估在特定目的中从LAT-1底物优化的SAR 1 2可以应用于改善前药细胞摄取。此外，连接sn-38和 氨基酸促进剂可能会对前药药物和功效产生重大影响，将会产生重大影响 被检查。该项目为治疗大脑和其他许多不同的疾病都有广泛的应用 LAT-1大量表达的组织，包括癌症。