Endothelial cell-specific over-expression of endothelin-1 leads to more severe cerebral damage following transient middle cerebral artery occlusion

J Cardiovasc Pharmacol. 2004 Nov:44 Suppl 1:S293-300. doi: 10.1097/01.fjc.0000166277.70538.b0.

Abstract

Previously, we have demonstrated that mRNA expression of endothelin-1 (ET-1), a potent vasoconstrictor, is induced in astrocytes and endothelial cells after ischemic conditions, suggesting that both of these cells synthesize ET-1 under this stress condition. Furthermore, ET-1 protected primary cultured astrocytes from ischemic stress. In order to further investigate the role of endothelial ET-1 in cerebral ischemic injury, transgenic mouse lines (TET) with a transgene that included ET cDNA with SV40 polyA under tyrosine kinase with immunoglobulin and epidermal growth factor homology domain (Tie-1) promoter were used. TET mouse lines were further characterized for ET-1 over-expression in the brain. The reverse transcription-polymerase chain reaction (RT-PCR) analysis using the primers specific for transgene ET-1 showed that transgene ET-1 is only expressed in the brain from TET mice. Total expression of ET- 1 mRNA was also increased in the transgenic brain compared with the non-transgenic brain by semi-quantitative RT-PCR. In situ hybridization and immunocytochemical analyses showed that the increased ET-1 mRNA and peptide expressions were detected in endothelial cells of cerebral vessels of TET mice. Under normal conditions, the TET mice that have a slightly increased blood pressure compared with that of non-transgenic mice showed no gross morphological abnormalities in the brain. However, after transient middle cerebral artery occlusion, TET mice showed a more severe neurological deficit, and larger infarct size and volume, suggesting that over-expressing ET-1 in endothelial cells is deleterious to neuronal survival under ischemic conditions. Our present TET model will serve as an ideal model for studying the role of endothelial ET- 1 in the pathogenesis of ischemic stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / blood supply*
  • Brain / pathology
  • Cell Death
  • Disease Models, Animal
  • Endothelin-1 / genetics
  • Endothelin-1 / metabolism*
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / pathology
  • Hippocampus / blood supply
  • Hippocampus / pathology
  • Immunohistochemistry
  • In Situ Hybridization
  • Infarction, Middle Cerebral Artery / genetics
  • Infarction, Middle Cerebral Artery / metabolism*
  • Infarction, Middle Cerebral Artery / pathology
  • Male
  • Mice
  • Mice, Transgenic
  • Nerve Degeneration / genetics
  • Nerve Degeneration / metabolism*
  • Nerve Degeneration / pathology
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Severity of Illness Index
  • Up-Regulation

Substances

  • Endothelin-1
  • RNA, Messenger