title: Closing the gap between the in-vivo and in-vitro blood-brain barrier tightness.
abstract: Numerous in-vitro models of the blood-brain barrier (BBB) have been developed in the hope to mimic as closely as possible the in-vivo BBB characteristics. Most models however display BBB tightness properties still very remote from those found in-vivo. We describe here the properties of an in-vitro BBB model in three configurations: primary porcine brain endothelial cells (PBEC) grown in a monoculture, or as a co-culture in close proximity to rat glial cells (contact), or with the latter at distance (non-contact). The BBB tightness as reflected by measurements of the permeability (Pe) to sucrose and of the transendothelial electrical resistance (TEER) showed that only the contact co-culture closely mimic the in-vivo BBB (Pe=0.1910(-6)+/-0.01 cm/s and TEER up to 1650 Omegacm2). While no changes in the expression pattern of three of the major tight junction proteins, claudin-5, occludin and ZO-1, were observed using immunohistochemistry, western blot analysis showed that the expression levels of claudin-5 and occludin increase when PBEC are cultured in contact with glial cells. In addition, we found, in the contact co-culture model, a reduced sensitivity of the TEER to vinblastine, a P-glycoprotein (Pgp) substrate that disrupts the cell cytoskeleton, indicating an improved functionality of the Pgp transporters in this configuration. We conclude that the close proximity of astrocytes is crucial to the development of a tight BBB.
authors.affiliation: Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Katayun
authors.initials: K
authors.lastname: Cohen-Kashi Malina
authors.forename: Itzik
authors.initials: I
authors.lastname: Cooper
authors.forename: Vivian I
authors.initials: VI
authors.lastname: Teichberg
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000648:ultrastructure; D015153:Blotting, Western; D002450:Cell Communication / Q000502:physiology; D002478:Cells, Cultured; D062507:Claudin-5; D018920:Coculture Techniques / Q000379:methods*; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism; D023421:Models, Animal; D009457:Neuroglia / Q000166:cytology* / Q000378:metabolism; D062793:Occludin; D010539:Permeability; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D013395:Sucrose / Q000378:metabolism / Q000493:pharmacokinetics; D013552:Swine; D019108:Tight Junctions / Q000378:metabolism; D050257:Tubulin Modulators / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology; D062826:Zonula Occludens-1 Protein
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D062507:Claudin-5; C491510:Cldn5 protein, rat; D008565:Membrane Proteins; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D050257:Tubulin Modulators; D062826:Zonula Occludens-1 Protein; D013395:Sucrose; D014747:Vinblastine