In vitro models of blood-brain barrier set by co-culturing primary pericytes, astrocytes and brain capillary endothelial cells

Abstract

The blood-brain barrier (BBB) is formed by brain capillary endothelial cells (BCECs) under the effects of the brain microenvironment. BCECs are sealed together by tight junctions (TJs) [2]. We previously found that occludin, one of the main TJ components, is correctly localized at the cell periphery only if BCECs are co-cultured with neurons/astrocytes [1-2]. Moreover, pericytes induce PLA2 protein expression through activation of PKCalpha and the MAPK/ERK cascade in immortalized GP8.3 endothelial cells [3]. In the present work, we analyzed the effects of pericytes and/or astrocytes on survival and differentiation of primary endothelial cells, in the presence of a serum-free medium. To test formation of BBB, we measured TEER and the amount of 3H-sucrose crossing the BCEC layer. We also analyzed peripheral localization of occludin. Interestingly, we found that both astrocytes and pericytes, in addition to their effects on BBB formation, also improve survival of BCECs.