The blood vessel endothelial cells of the BBB are cemented together by protein structures called tight junctions (1), preventing diffusion of most molecules between cells. BBB endothelial cells display transporters (2), receptors (3), and channels (4) that facilitate selective transport of vital nutrients into the CNS. They also possess efflux pumps, such as P-glycoprotein, that expel most small, amphiphilic molecules that are soluble in the blood and in cell lipid membranes (5). Pericytes and astrocyte pseudopods serve as an additional physical barrier between the blood vessel and brain tissue, and support the expression of endothelial cell genes required to maintain the BBB.
© 2017, LISA CLARK
Designing drugs to reach the CNS requires some creativity on the part of researchers. The approaches vary from disrupting the BBB’s tight junctions ...
