Astrocytes blood-brain barrier interactions

Abbott, N.J. 2002. Astrocyte-endothelial cell interactions and blood-brain barrier permeability. J Anat 200 629. 

Abbott NJ, Ronnback L, Hansson E. Astrocyte-endothelial interactions at the blood-brain barrier. Nat Rev Neurosci 2006 7(l) 41-53. 

Instead of using cococulteres with rat astrocytes, some laboratories are also using astrocytic conditioned medium in order to reinduce blood-brain barrier properties (Dehouck et al. 1994). They have found that induction does not require direct cell-cell interactions. 

Figure 4.1. The vascular blood-brain barrier three levels of complexity. The upper panel illustrates the brain endothelial cell. This is the functional and anatomical site of both barrier function and of saturable and non-saturable mechanisms of passage. The major modifications allowing both barrier function and selective penetration of substances are indicated. The middle panel illustrates other ceU types and structures important in BBB function. Pericytes are embedded in a basement membrane and astrocytes form a net-like structure over the capillary bed. Both cell types are in paracellular communication with the brain endothelial cells. Pericytes and astrocytes to some extent oppose each others effects on BBB fnnctions. The lower panel illnstrates the neurovascnlar nnit, a concept, that emphasizes integration of peripheral, BBB, and central interactions.

Abbott NJ (2002) Astrocyte endothelial interaction and blood brain barrier. Permeability. A Anat 200 629-638. 

Abbott, N.J. (2002) Astrocyte-endotheUal interactions and blood—brain barrier permeability. Journal of Anatomy, 200, 629-638. 

Cells of the CNS directly interact with other cell types, notably the capillary endothelial cells that comprise the blood-brain barrier (BBB). Astrocytes are essential for the maintenance of BBB structural integrity ami permeability... 

The neurovascular unit places stroke in the context of an integrative tissue response in which all cellular and matrix elements, not just neurons or blood vessels, are players in the evolution of tissue injury. For example, efficacy of the blood-brain barrier is critically dependent upon endothelial-astrocyte-matrix interactions [93]. Disruption of the neurovascular matrix, which includes basement membrane components such as type IV collagen, heparan sulfate proteoglycan, laminin, and... 

FIGURE 14.16 Schematic view of the blood-brain barrier. Endothelial cells form a continuous layer covering the inner surface of blood microvessels. At the point of contacts with brain tissues, these endothelial cells interact with pericytes and astrocytes. Nerve ending with specific neurotransmitters can also be observed. The light junctions (TJ) that link endothelial cells act as a physical barrier that blocks the paraceUular route and forces the molecular traffic to take the transceUijlar pathway (double arrows). 

CucuUo L, McAUister MS, Kight K, Krizanac-Bengez L, Marroni M, Mayberg MR, Stanness KA, Janigro D, 2002. A new dynamic in vitro model for the multidimensional study of astrocyte-endotheUal ceU interactions at the blood-brain barrier. Brain Res. 951(2) 243. 

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