Absence of Glial alpha-Dystrobrevin Causes Abnormalities of the Blood-Brain Barrier and Progressive Brain Edema

作者：Lien Chun Fu; Mohanta Sarajo Kumar; Frontczak Baniewicz Malgorzata; Swinny Jerome D; Zablocka Barbara; Gorecki Dariusz C^*

来源：Journal of Biological Chemistry, 2012, 287(49): 41374-41385.

DOI：10.1074/jbc.M112.400044

The blood-brain barrier (BBB) plays a key role in maintaining brain functionality. Although mammalian BBB is formed by endothelial cells, its function requires interactions between endotheliocytes and glia. To understand the molecular mechanisms involved in these interactions is currently a major challenge. We show here that alpha-dystrobrevin (alpha-DB), a protein contributing to dystrophin-associated protein scaffolds in astrocytic endfeet, is essential for the formation and functioning of BBB. The absence of alpha-DB in null brains resulted in abnormal brain capillary permeability, progressively escalating brain edema, and damage of the neurovascular unit. Analyses in situ and in two-dimensional and three-dimensional in vitro models of BBB containing alpha-DB-null astrocytes demonstrated these abnormalities to be associated with loss of aquaporin-4 water and Kir4.1 potassium channels from glial endfeet, formation of intracellular vacuoles in alpha-DB-null astrocytes, and defects of the astrocyte-endothelial interactions. These caused deregulation of tight junction proteins in the endothelia. Importantly, alpha-DB but not dystrophins showed continuous expression throughout development in BBB models. Thus, alpha-DB emerges as a central organizer of dystrophin-associated protein in glial endfeet and a rare example of a glial protein with a role in maintaining BBB function. Its abnormalities might therefore lead to BBB dysfunction.

• 出版日期2012-11-30