Immortalized Rat Brain Microvessel Endothelial Cells: I - Expression of Blood-Brain Barrier Markers During Angiogenesis

Abstract

The blood-brain barrier (BBB) controls the exchange of solutes between the blood and the brain parenchyma. It is constituted by the endothelial cells lining the brain microvessels, in close relationship with astrocytes. These endothelial cells display a unique phenotype, characterized essentially by the presence of numerous intercellular tight junctions and the expression of specific enzymes, like γ-glutamyltranspeptidase (γ-GT) and alkaline phosphatase. It is known that the induction of this endothelial phenotype is controlled in vivo by the perivascular astrocytes. The in vitro study of the molecular mechanisms of this induction has been dependent so far on the availability of primary cultures of brain microvessel endothelial cells. In order to get rid of the intrinsic drawbacks of such primary cultures, i.e., contamination by various cell types and rapidly appearing senescence, we immortalized rat brain microvessel endothelial cells by transfection with the E1A-Adenovirus encoding gene. This study describes a phenotypic and pharmacological characterization of the immortalized cellular clone RBE4 and presents evidence for the expression by these cells of BBB enzymatic markers during angiogenesis.KeywordsAlkaline Phosphatase ActivityMicrovascular Endothelial CellBrain MicrovesselRBE4 CellBrain Microvessel Endothelial CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.