title: Bioluminescent imaging of ABCG2 efflux activity at the blood-placenta barrier.
abstract: 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.
authors: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,U.S.A.
authors: Jeyan S
authors: JS
authors: Kumar
authors: Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD20892, U.S.A.
authors: Bih-Rong
authors: BR
authors: Wei
authors: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,U.S.A.
authors: James P
authors: JP
authors: Madigan
authors: Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD20892, U.S.A.
authors: R Mark
authors: RM
authors: Simpson
authors: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,U.S.A.
authors: Matthew D
authors: MD
authors: Hall
authors: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,U.S.A.
authors: Michael M
authors: MM
authors: Gottesman
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2 / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D052160:Benzothiazoles / Q000493:pharmacokinetics / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects*; D001812:Blood-Brain Barrier / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015153:Blotting, Western; D002478:Cells, Cultured; D002822:Choriocarcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D000077156:Gefitinib; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D049409:Luciferases, Firefly / Q000493:pharmacokinetics; D049408:Luminescent Agents / Q000493:pharmacokinetics; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010920:Placenta; D011247:Pregnancy; D011799:Quinazolines / Q000493:pharmacokinetics / Q000494:pharmacology; D014018:Tissue Distribution
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; C501412:Abcg2 protein, mouse; D000970:Antineoplastic Agents; D052160:Benzothiazoles; C532924:D-luciferin; D049408:Luminescent Agents; D011799:Quinazolines; D049409:Luciferases, Firefly; D000077156:Gefitinib