Immunolocalization of dystrobrevin in the astrocytic endfeet and endothelial cells in the rat cerebellum.

Dystrobrevin is a newly discovered dystrophin-associated protein that is classified as alpha- and beta-dystrobrevin. Previous studies reported that dystrophin, utrophin, syntrophin and beta-dystroglycan were expressed in the cerebellum. In the present study, we examined cellular and subcellular localization of dystrobrevin in the adult rat cerebellum immunohistochemically. Confocal microscopy showed that dystrobrevin was expressed around blood vessels and under the pia mater as dystrophin, utrophin and beta-dystroglycan were. Immunoelectron microscopy demonstrated that dystrobrevin was localized not only in the astrocytic endfeet around blood vessels and under the pia mater, but also in endothelial cells. Considering the fact that dystrobrevin possesses multiple phosphotyrosine kinase residues, these data suggest that dystrobrevin plays a role in blood-brain barrier functions as a component of the dystrophin complex.