Intestinal Drug Transporters in Veterinary Animals

兽用动物的肠道药物转运蛋白 三磷酸腺苷结合盒家族(ABC)中的肠道转运体减少了许多外来物质的吸收 包括处方药。ABCG2编码BCRP，这是一种重要的转运蛋白，在 肠道以及其他屏障组织，如血脑屏障。BCRP限制其口服生物利用度 它的底物和被发现与BCRP高度相互作用的候选药物经常被丢弃 在药物研发过程中。只有那些与BCRP互动有限或没有互动的人才会被选作进一步的选择 发展。然而，对于兽药开发，表达适当物种的细胞系 BCRP的同源基因不可用。由于底物和缓蚀剂选择性的物种差异 转运蛋白很可能发生，缺乏表达转运蛋白同源基因的细胞系代表了一种 兽药发展的巨大差距。此第一阶段SBIR研究的目标是创建和 稳定表达兽用动物BCRP的细胞系和酵母菌株的鉴定 羊和猪。这些细胞系和酵母菌株将作为药物开发商的资源，并将代表 创新“替代方法，支持动物活动的替代/减少/改进 研究。“在目标1的研究中，我们将创造稳定的细胞系和表达该物种的酵母菌株。 BCRP的同源同源物。在目标2中，我们将创建可靠的分析方法，并使用BCRP的模型底物和抑制剂来 表征底物的物种差异和转运蛋白的抑制剂专一性。中使用的方法 建议的研究包括用于创建稳定表达转运蛋白同源基因的细胞系的技术， 以及细胞中的同位素摄取和通量分析。酵母转化程序和细胞毒性检测也将 被应用。总的来说，这些研究将通过提供急需的细胞来促进兽药的开发 用于预测药物吸收的线条。细胞系将减少对反复试验的依赖 在动物身上的方法。

Intestinal Drug Transporters in Veterinary Animals Intestinal transporters in the ATP Binding Cassette Family (ABC) reduce the absorption of many xenobiotics including prescription drugs. ABCG2 encodes BCRP, an important transporter that is highly expressed in the intestine as well as other barrier tissues such as the Blood Brain Barrier. BCRP limits the oral bioavailability of its substrates and therefore candidate drugs that are found to highly interact with BCRP are often discarded during drug development. Only those with limited or no interactions with BCRP are selected for further development. However, for veterinary drug development, cell lines expressing the appropriate species orthologs of BCRP are not available. Since species differences in the substrate and inhibitor selectivity of transporters are likely to occur, the lack of cell lines expressing species orthologs of transporters represents an enormous gap for veterinary drug development. The goals of this Phase I SBIR research are to create and characterize cell lines and yeast strains stably expressing veterinary animal BCRP from dog, cat, sheep and pig. The cell lines and yeast strains will serve as resources for drug developers, and will represent innovative “alternative methods, in support of replacement/reduction/refinement for activities involving animal research.” In studies under aim 1, we will create stable cell lines and yeast strains expressing the species orthologs of BCRP. In aim 2, we will create robust assays and use model substrates and inhibitors of BCRP to characterize species differences in the substrate and inhibitor specificity of the transporter. Methods used in the proposed studies include technologies for creation of cell lines stably expressing the transporter orthologs, and isotopic uptake and flux assays in cells. Yeast transformation procedures and cytotoxicity assays will also be applied. Collectively these studies will enable veterinary drug development by providing much needed cell lines for predicting drug absorption. The cell lines will reduce the reliance on trial-and-error experimental approaches in animals.