Elucidation of disease-related changes of drug brain distributions based on intrinsic efflux activity and absolute expression level of P-glycoprotein at the brain barrier

本研究旨在建立一种方法学来阐明疾病状态下血脑屏障（BBB）上P-糖蛋白（P-gp）的药物外排功能。我们的实验表明，在疾病的绝对蛋白质表达水平的P-gp的变化（癫痫），在体内功能的P-gp在血脑屏障可以重建从在体外通过整合每一个P-gp分子的外排活性在其过表达的细胞系和绝对表达水平在分离的脑毛细血管。我们发现，在每一个P-gp分子的外排活性发生变化的疾病状态（炎性氧化应激）中，小窝蛋白1 Tyr 14的磷酸化水平是估计活性变化的生物标志物之一。本研究还在猴和啮齿类动物中证实了P-gp功能的重建，为从体外系统阐明疾病中P-gp在人血脑屏障的外排功能开辟了新的途径。

This study aimed to establish a methodology to clarify drug efflux function of P-glycoprotein (P-gp) at the blood-brain barrier (BBB) in disease conditions. We experimentally demonstrated that, in the disease which the absolute protein expression level of P-gp changes (epilepsy), the in vivo function of P-gp at the BBB can be reconstructed from in vitro by integrating the efflux activity per one P-gp molecule measured in its overexpressing cell lines and the absolute expression level in isolated brain capillaries. We found that, in the disease condition which the efflux activity per one P-gp molecule changes (inflammatory oxidative stress), the phosphorylation level of caveolin1 Tyr14 is one of the biomarkers to estimate the change of the activity. We also demonstrated the reconstruction of P-gp function in monkeys as well as rodents, and opened the new way to clarify the efflux function of P-gp at the human BBB in diseases from in vitro system.