Secretion of interleukin-1beta by astrocytes mediates endothelin-1 and tumour necrosis factor-alpha effects on human brain microvascular endothelial cell permeability

J Neurochem. 2003 Jul;86(1):246-54. doi: 10.1046/j.1471-4159.2003.01829.x.


Evidence suggests that endothelin-1 (ET-1) plays an essential role in brain inflammation. However, whether ET-1 contributes directly to blood-brain barrier (BBB) breakdown remains to be elucidated. Using an in vitro BBB model consisting of co-cultures of human primary astrocytes and brain microvascular endothelial cells (BMVECs), we first investigated the expression of ET-1 by BMVECs upon stimulation with tumour necrosis factor (TNF)-alpha, which plays an essential role in the induction and synthesis of ET-1 during systemic inflammatory responses. Increased ET-1 mRNA was detected in the human BMVECs 24 h after TNF-alpha treatment. This was correlated with an increase in ET-1 levels in the culture medium, as determined by sandwich immunoassay. Both TNF-alpha and ET-1 increased the permeability of human BMVECs to a paracellular tracer, sucrose, but only in the presence of astrocytes. The increase in BMVEC permeability by TNF-alpha was partially prevented by antibody neutralization of ET-1 and completely by monoclonal antibody against IL-1beta. Concomitantly, TNF-alpha induced IL-1beta mRNA expression by astrocytes in co-culture and this effect was partially prevented by ET-1 antibody neutralization. In parallel experiments, treatment of human primary astrocytes in single cultures with ET-1 for 24 h induced IL-1beta mRNA synthesis and IL-1beta protein secretion in the cell culture supernatant. Taken together, these results provide evidence for paracrine actions involving ET-1, TNF-alpha and IL-1beta between human astrocytes and BMVECs, which may play a central role in BBB breakdown during CNS inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Astrocytes / cytology
  • Astrocytes / metabolism*
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / physiology
  • Brain / blood supply
  • Capillary Permeability / drug effects*
  • Capillary Permeability / physiology
  • Cells, Cultured
  • Coculture Techniques
  • Endothelin-1 / biosynthesis
  • Endothelin-1 / pharmacology*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / metabolism
  • Humans
  • Interleukin-1 / biosynthesis*
  • Interleukin-1 / genetics
  • Interleukin-1 / metabolism
  • Microcirculation / cytology
  • RNA, Messenger / biosynthesis
  • Tumor Necrosis Factor-alpha / pharmacology*


  • Endothelin-1
  • Interleukin-1
  • RNA, Messenger
  • Tumor Necrosis Factor-alpha