Intestinal Drug Transporters in Veterinary Animals

兽医动物肠道药物转运蛋白 ATP结合盒家族（ABC）中的肠道转运蛋白减少许多外源性物质的吸收 包括处方药ABCG 2编码BCRP，BCRP是一种重要的转运蛋白， 肠以及其他屏障组织如血脑屏障。BCRP限制了 它的底物和因此发现与BCRP高度相互作用的候选药物经常被丢弃 在药物开发过程中。仅选择与BCRP相互作用有限或无相互作用的药物进行进一步研究。 发展然而，对于兽药开发，表达适当种属的细胞系 BCRP的直系同源物不可用。由于底物和抑制剂选择性的物种差异， 由于可能存在转运蛋白，缺乏表达转运蛋白物种直系同源物的细胞系代表了 兽药开发的巨大缺口。第一阶段SBIR研究的目标是创建和 表征稳定表达来自犬、猫的兽医动物BCRP的细胞系和酵母菌株， 羊和猪细胞系和酵母菌株将作为药物开发人员的资源，并将代表 创新“替代方法，以支持替代/减少/改进涉及动物的活动 研究”在aim 1的研究中，我们将创建稳定的细胞系和表达该物种的酵母菌株 BCRP的直系同源物。在目标2中，我们将建立稳健的检测方法，并使用BCRP的模型底物和抑制剂， 表征转运蛋白的底物和抑制剂特异性的物种差异。中使用的方法 所提出的研究包括产生稳定表达转运蛋白直系同源物的细胞系的技术， 以及细胞中的同位素摄取和通量测定。酵母转化程序和细胞毒性测定也将 被应用。总的来说，这些研究将通过提供急需的细胞， 用于预测药物吸收的线。该细胞系将减少对试错实验的依赖 接近动物。

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.