Evaluation of bEnd5 cell line as an in vitro model for the blood–brain barrier under normal and hypoxic/aglycemic conditions

The purpose of the study was to assess the suitability of the mouse endothelial cell line bEnd5 as a blood–brain barrier (BBB) model under normal or pathologic (stroke) conditions. In comparison to the well-established bovine brain endothelial cell (BBMEC) model, cultured bEnd5 monolayers reached a maximal transendothelial electrical resistance (TEER) of 121 Ω cm² on day 7, and possessed oval and spindle shape morphology. Structurally, confluent monolayers of bEnd5 cells and BBMECs exhibit peripheral band staining of the tight junction protein ZO-1 and occludin. Both bEnd5 and BBMECs express important tight junctional proteins, ZO-1, occludin and claudin-1, as well as the transporters P-glycoprotein (P-gp), NKCC, GLUT1, and most PKC isoforms. Marker permeability experiments suggest that bEnd5 cells form a tight barrier that compares to well-established in vitro BBB models, such as the BBMEC. After short durations of hypoxia/aglycemia (H/A), hyperpermeability was seen in the bEnd5 endothelial monolayer compared to later time periods for BBMECs, suggesting that bEnd5 cells are more sensitive to hypoxia/algycemia treatment than BBMECs. Taken together, bEnd5 cell culture model may provide a useful in vitro model of the BBB for drug delivery studies and modeling pathological states such as oxygen glucose deprivation associated with stroke. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 3196–3213, 2007