Characterization transgenic mice with the overexpression of ET-1 in endothelial cells as a model for experimental ischemic stroke

Abstract

Endothelin-1 (ET-1), a potent vasoconstrictor, has been suggested to play a crucial role in cerebral ischemia. Previously, we have demonstrated that the ET-1 expressions were induced in astrocytic and endothelial cell after ischemic condition. Furthermore, ET-1 protected primary cultured astrocytes from hypoxic/ischemic injury. However, transgenic mice with overexpression of ET-1 in astrocytes displayed more severe neurological deficit and increased infract volume suggesting high level of astrocytic ET-1 have neurotoxic effect on neurons. In order to further investigate the role of endothelial ET-1 on neurological deficit and infarct after cerebral ischemia in vivo, several transgenic mouse lines were generated by injecting the construct which include ET cDNA and SV40 polyA under tyrosin kinase receptor-specific for endothelial cell (Tie-1) promoter which was shown to target reporter gene to endothelial cells. Over-expression of transgene, ET-1, in TET mouse brain has been characterized by reverse-transcription PCR and quantified by ribonuclease protection assay. Furthermore, the site of ET-1 over-expression in TET mice was determined by in situ hybridization. Our present TET model will serve as an ideal model for studying the pathophysiological mechanism of ischemic stroke. Keywords: endothelin-1, ischemic stroke, middle cerebral artery occlusion, nitric oxide.