title: Characterization of a novel brain barrier ex vivo insect-based P-glycoprotein screening model.
abstract: In earlier studies insects were proposed as suitable models for vertebrate blood-brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain barrier of the desert locust (Schistocerca gregaria). In an in vivo study on the locust, we found an increased uptake of the two well-known Pgp substrates, rhodamine 123 and loperamide after co-administration with the Pgp inhibitors cyclosporine A or verapamil. Furthermore, ex vivo studies on isolated locust brains demonstrated differences in permeation of high and low permeability compounds. The vertebrate Pgp inhibitor verapamil did not affect the uptake of passively diffusing compounds but significantly increased the brain uptake of Pgp substrates in the ex vivo model. In addition, studies at 2°C and 30°C showed differences in brain uptake between Pgp-effluxed and passively diffusing compounds. The transcriptome data show a high degree of sequence identity of the locust Pgp transporter protein sequences to the human Pgp sequence (37%), as well as the presence of conserved domains. As in vertebrates, the locust brain-barrier function is morphologically confined to one specific cell layer and by using a whole-brain ex vivo drug exposure technique our locust model may retain the major cues that maintain and modulate the physiological function of the brain barrier. We show that the locust model has the potential to act as a robust and convenient model for assessing BBB permeability in early drug discovery.
authors.affiliation: EntomoPharm, R&D Medicon Village, S-223 81, Lund, Sweden.
authors.forename: Olga
authors.initials: O
authors.lastname: Andersson
authors.affiliation: Department of Animal Physiology and Neurobiology, Katholieke Universiteit Leuven Leuven, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Badisco
authors.affiliation: EntomoPharm, R&D Medicon Village, S-223 81, Lund, Sweden.
authors.forename: Ane Håkansson
authors.initials: AH
authors.lastname: Hansen
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen DK-2100, Copenhagen, Denmark.
authors.forename: Steen Honoré
authors.initials: SH
authors.lastname: Hansen
authors.affiliation: EntomoPharm, R&D Medicon Village, S-223 81, Lund, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Hellman
authors.affiliation: EntomoPharm, R&D Medicon Village, S-223 81, Lund, Sweden.
authors.forename: Peter Aadal
authors.initials: PA
authors.lastname: Nielsen
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen DK-2100, Copenhagen, Denmark.
authors.forename: Line Rørbæk
authors.initials: LR
authors.lastname: Olsen
authors.affiliation: Department of Animal Physiology and Neurobiology, Katholieke Universiteit Leuven Leuven, Belgium.
authors.forename: Rik
authors.initials: R
authors.lastname: Verdonck
authors.affiliation: BBB Group, Institute of Pharmaceutical Science, King's College London Franklin Wilkins Building, London, SE1 9NH, United Kingdom.
authors.forename: N Joan
authors.initials: NJ
authors.lastname: Abbott
authors.affiliation: Department of Animal Physiology and Neurobiology, Katholieke Universiteit Leuven Leuven, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Vanden Broeck
authors.affiliation: EntomoPharm, R&D Medicon Village, S-223 81, Lund, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Andersson
keywords: Brain–barrier permeability; Pgp-transporter; efflux transporter; insect brain barrier; screening model