F-actin Cytoskeleton and Sucrose Permeability of Immortalised Rat Brain Microvascular Endothelial Cell Monolayers: Effects of Cyclic AMP and Astrocytic Factors

Brain Res. 1997 Sep 12;768(1-2):10-8. doi: 10.1016/s0006-8993(97)00586-6.


The immortalised RBE4 cell line, derived from rat brain capillary endothelial cells, preserves many features of the in vivo brain endothelium, and hence is of interest as a potential in vitro model of the blood-brain barrier (BBB). This study reports the effects of elevated intracellular cAMP and factors released by astrocytes on the F-actin cytoskeleton and paracellular sucrose permeability of monolayers of RBE4 cells. RBE4 cells grown in control medium showed a marked increase in the F-actin staining at the cytoplasmic margin at confluence, which was not significantly enhanced by elevation of intracellular cAMP and/or addition of astrocyte-conditioned medium (ACM). The formation of the marginal band of F-actin was accompanied by an increase in the F-actin content of the RBE4 cells up to confluence, and a decline in F-actin content thereafter. Elevation of intracellular cAMP or co-culture above astrocytes significantly decreased the paracellular sucrose permeability of confluent RBE4 cell monolayers grown on collagen filters (P < 0.01 and P < 0.001, respectively). Co-culture above astrocytes together with elevated cAMP also produced a significant decrease in the sucrose permeability of the monolayer (P < 0.01) but this was no greater than with astrocytes alone. These findings show that the RBE4 cell line may serve as a useful in vitro model for the study of brain endothelial cell physiology and agents which alter the permeability of the BBB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Astrocytes / metabolism
  • Capillary Permeability / drug effects*
  • Cell Line
  • Cell Survival / drug effects
  • Cyclic AMP / pharmacology*
  • Cytoskeleton / drug effects*
  • Endothelium, Vascular / drug effects*
  • Microcirculation / drug effects
  • Microscopy, Fluorescence
  • Rats
  • Sucrose / pharmacokinetics*


  • Actins
  • Sucrose
  • Cyclic AMP