Thursday, July 12, 2012
Figure 1. Building
a better blood brain barrier.
Lippmann et al. have modeled the blood brain barrier (BBB) in vitro
using human pluripotent stem cells.
technique involves treating undifferentiated human pluripotent stem cells [a] with cell culture medium that has
previously been used to grow endothelial cells. The stem cells differentiate
into a mixed population of neuronal and endothelial cell precursors [b]
that express tight junction markers. The neurons in the mixed culture secrete
developmental factors including wingless-type MMTV integration site (WNT)
family members that guide the differentiation of endothelial cells [c].
When cultured with rat astrocytes in an in vitro BBB assay, the
resulting endothelial cells form tight junctions and show BBB activity,
including the transport of brain-permeant compounds [d] and the
exclusion of brain-impermeant compounds [e].