Kumar Jeyan S, Wei Bih-Rong, Madigan James P, Simpson R Mark, Hall Matthew D, Gottesman Michael M
Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,U.S.A.
Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD20892, U.S.A.
Sci Rep. 2016 Feb 8;6:20418. doi: 10.1038/srep20418.
Physiologic barriers such as the blood placenta barrier (BPB) and the blood brain barrier protect the underlying parenchyma from pathogens and toxins. ATP-binding cassette (ABC) transporters are transmembrane proteins found at these barriers, and function to efflux xenobiotics and maintain chemical homeostasis. Despite the plethora of ex vivo and in vitro data showing the function and expression of ABC transporters, no imaging modality exists to study ABC transporter activity in vivo at the BPB. In the present study, we show that in vitro models of the placenta possess ABCG2 activity and can specifically transport D-luciferin, the endogenous substrate of firefly luciferase. To test ABCG2 transport activity at the BPB, we devised a breeding strategy to generate a bioluminescent pregnant mouse model to demonstrate transporter function in vivo. We found that coadministering the ABCG2 inhibitors Ko143 and gefitinib with D-luciferin increased bioluminescent signal from fetuses and placentae, whereas the control P-gp inhibitor DCPQ had no effect. We believe that our bioluminescent pregnant mouse model will facilitate greater understanding of the BPB and ABCG2 activity in health and disease.
生理屏障，如血胎盘屏障（BPB）和血脑屏障，可保护其下方的实质组织免受病原体和毒素的侵害。ATP结合盒（ABC）转运蛋白是在这些屏障处发现的跨膜蛋白，其功能是排出外源性物质并维持化学稳态。尽管有大量的体外和体内数据显示了ABC转运蛋白的功能和表达，但目前尚无成像方法可用于研究BPB处ABC转运蛋白在体内的活性。在本研究中，我们发现胎盘的体外模型具有ABCG2活性，并且能够特异性转运萤火虫荧光素酶的内源性底物D-荧光素。为了测试BPB处的ABCG2转运活性，我们设计了一种育种策略，以生成一种生物发光的妊娠小鼠模型，用于在体内证明转运蛋白的功能。我们发现，将ABCG2抑制剂Ko143和吉非替尼与D-荧光素共同给药可增加胎儿和胎盘的生物发光信号，而对照P-糖蛋白抑制剂DCPQ则没有效果。我们相信，我们的生物发光妊娠小鼠模型将有助于更深入地了解BPB以及健康和疾病状态下的ABCG2活性。
