Fig. 5.

Disrupted BTB structural elements in GBM. a Characteristic structure of brain BV elements in normal CTX. Overview of the architectural integrity of brain BV formed by protoplasmic astrocytic endfeet, COL-IV basement membrane and CD31 endothelium (1). 3D detail of a BV-related protoplasmic astrocyte (2). Higher magnification of the brain vessel integrity (3). Diagram of the normal CTX BBB elements (4). b Characteristic disrupted structure of brain BV elements in GBM. Overview of the altered vascular structure in GBM gemistocytic tumor nest (1). Detail of classical GBM gemistocyte on disorganized basement membrane (2). Detail of the intermingled elements of the GBM associated vessels (3). Diagram of the GBM BTB elements (4). c 3D reconstruction of a normal cortical BV (Large increments in frame are 5 μm). d 3D reconstruction of a GBM-associated BV (Small increments in frame are 5 μm). e Diagram illustrating the alterations in GBM-associated BV versus non-tumor BV