Ja. Wijsman et Rr. Shivers, Immortalized mouse brain endothelial cells are ultrastructurally similar to endothelial cells and respond to astrocyte-conditioned medium, IN VITRO-AN, 34(10), 1998, pp. 777-784
Studies of brain microvessel endothelial cell physiology and blood-brain ba
rrier properties are often hampered by the requirement of repeatedly produc
ing and characterizing primary endothelial cell cultures. The use of viral
oncogenes to produce several immortalized brain microvessel cell lines has
been reported. The resulting cell lines express many properties of the bloo
d-brain barrier phenotype but do not completely mimic primary endothelial c
ells in culture. As immortalized brain microvessel endothelial cell lines h
ave not yet been produced from mice, we transformed mouse brain endothelial
cells with the adenovirus E1A gene using a retroviral vector (DOL). Eight
of 11 clones produced exhibited an endothelial-like cobblestone morphology
and were characterized as endothelial with a panel of antibodies, lectins,
and ultrastructural criteria. These cells are endothelial in origin and sha
re ultrastructural features with primary cultures of endothelial cells. Exa
mination of freeze fracture and transmission electron micrographs show adhe
rens junctions exist between the transformed cells, and culture in astrocyt
e-conditioned medium induces the formation of gap junctions. This is one in
dication that responses to astrocyte-derived factors are retained by the tr
ansformed cell lines.