Induction of blood-brain barrier differentiation in a rat brain-derived endothelial cell line.

An immortalized brain capillary endothelial cell line displaying blood-brain barrier characteristics may represent a useful tool for studying blood-brain barrier endothelial cell differentiation and for the in vitro prediction of drug brain penetration. In the present study, we have established a rat cerebral capillary endothelial cell line (CR3) by genomic introduction of the immortalizing SV40 large T gene under the control of the human vimentin promoter. The CR3 cell line displayed endothelial morphological and biochemical characteristics for up to 30 passages. However, the CR3 cell line did not spontaneously express the specific blood-brain barrier markers gamma-glutamyl transpeptidase and mdr P-glycoprotein. However, when the cells were treated with the cell differentiating agent all-trans-retinoic acid, the blood-brain barrier markers were induced. Retinoic acid-treated CR3 cells may thus represent a useful tool for biological and pharmacological research related to the blood-brain barrier.