Figure 1.

Schematic view of the blood–brain barrier (BBB) and the β1-integrin/matrix interactions proposed to support blood–brain barrier integrity. (Bottom left) Brain endothelial cells are surrounded by the endothelial basement membrane, in which a high number of pericytes is embedded. A second—the parenchymal—basement membrane is layed down by astrocytes, which ensheath the abluminal aspect of brain microvessels with their endfeet. The crosstalk between the cellular and acellular elements of brain microvessels establishes a functional neurovascular unit. (Top right) The study by Osada et al demonstrates that β1-integrin engagement of brain endothelial cells to the endothelial basement membrane maintains intracellular signaling events that stabilize claudin-5 localization in BBB tight junctions (TJs) and BBB integrity.