In Vivo Bioluminescent Imaging of ATP-Binding Cassette Transporter-Mediated Efflux at the Blood–Brain Barrier
We provide a detailed protocol for imaging ATP-binding cassette subfamily G member 2 (ABCG2) function at the blood–brain barrier (BBB) of transgenic mice. d-Luciferin is specifically transported by ABCG2 found on the apical side of endothelial cells at the BBB. The luciferase–luciferin enzymatic reaction produces bioluminescence, which allows a direct measurement of ABCG2 function at the BBB. Therefore bioluminescence imaging (BLI) correlates with ABCG2 function at the BBB and this can be measured by administering luciferin in a mouse model that expresses luciferase in the brain parenchyma. BLI allows for a relatively low-cost alternative for studying transporter function in vivo compared to other strategies such as positron emission tomography. This method for imaging ABCG2 function at the BBB can be used to investigate pharmacokinetic inhibition of the transporter.
Key wordsd-Luciferin BCRP ABCG2 Optical imaging Neuroimaging
We thank Mr. George Leiman for editorial assistance. This research was supported by the Intramural Research Program of the National Institutes of Health (NIH), National Cancer Institute. Joshua Bakhsheshian is a NIH Medical Research Scholar. The Medical Research Scholars Program is a public–private partnership supported jointly by the NIH and contributions to the Foundation for the NIH from Pfizer, the Leona M. and Harry B. Helmsley Charitable Trust, the Howard Hughes Medical Institute, as well as other private donors (listed at www.fnih.org/work/programs-development/medicalresearch-scholars-program).
- 10.Dickie M (1975) Keeping records in biology of the laboratory Mouse. Dover Publications, New York, NYGoogle Scholar
- 12.Allen JD, van Loevezijn A, Lakhai JM, van der Valk M, van Tellingen O, Reid G, Schellens JH, Koomen GJ, Schinkel AH (2002) Potent and specific inhibition of the breast cancer resistance protein multidrug transporter in vitro and in mouse intestine by a novel analogue of fumitremorgin C. Mol Cancer Ther 1:417–425CrossRefPubMedGoogle Scholar
- 21.Kanzaki S, Fujioka M, Yasuda A, Shibata S, Nakamura M, Okano HJ, Ogawa K, Okano H (2012) Novel in vivo imaging analysis of an inner ear drug delivery system in mice: comparison of inner ear drug concentrations over time after transtympanic and systemic injections. PLoS One 7:e48480CrossRefPubMedPubMedCentralGoogle Scholar