title: Transgenic mice over-expressing endothelial endothelin-1 show cognitive deficit with blood-brain barrier breakdown after transient ischemia with long-term reperfusion.
abstract: Increased level of endothelin-1 (ET-1), a potent vasoconstrictor, has been found in the cerebral spinal fluid (CSF) of patients with multi-infarction dementia, suggesting a possible role of ET-1 in cognitive deficit associated with stroke. Previously, we have reported that synthesis of ET-1 is induced in endothelial cells in hypoxic/ischemic conditions. Transgenic mice over-expressing endothelin-1 in endothelial cells (TET-1) developed systemic hypertension and showed more severe brain damage after transient ischemia. To further understand the significance of endothelial ET-1 in cognitive deficit, we subjected adult TET-1 mice to 30 min middle cerebral artery occlusion (MCAO) with 7 days reperfusion. At baseline, TET-1 mice showed similar locomotor activity, emotion and cognitive function compared to non-transgenic (NTg) mice. However, after 30 min MCAO and 7 days reperfusion, although the sensorimotor function measured by neurological scores was recovered in both genotypes, TET-1 mice showed increased anxiety-like behavior in the open field test and impaired spatial learning and reference memory in the Morris water maze. Parallel with these behavioral changes, TET-1 mice showed more severe brain damage with blood-brain-barrier breakdown (BBB), reactive astrogliosis, increased caspase-3, and increased peroxiredoxin 6 (Prx6) expressions around blood vessels in the ipsilateral hippocampus, compared to that of NTg mice, suggesting that ET-1 over-expression in the endothelial cells leads to more severe BBB breakdown and increased oxidative stress which may resulted in neuronal apoptosis and glial reactivity, which might contribute to the emotional changes and cognitive deficits after short-term ischemia with long-term reperfusion.
authors: Department of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors: Xu
authors: X
authors: Zhang
authors: Patrick K K
authors: PK
authors: Yeung
authors: Grainne M
authors: GM
authors: McAlonan
authors: Stephen S M
authors: SS
authors: Chung
authors: Sookja K
authors: SK
authors: Chung
mesh_terms: D000818:Animals; D001007:Anxiety / Q000503:physiopathology; D001522:Behavior, Animal; D001812:Blood-Brain Barrier / Q000378:metabolism / Q000503:physiopathology*; D002545:Brain Ischemia / Q000150:complications / Q000378:metabolism / Q000503:physiopathology; D053148:Caspase 3 / Q000378:metabolism; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D019332:Endothelin-1 / Q000235:genetics / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism*; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology; D051379:Mice; D008822:Mice, Transgenic; D018384:Oxidative Stress / Q000502:physiology; D054465:Peroxiredoxin VI / Q000378:metabolism; D015427:Reperfusion Injury / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D019332:Endothelin-1; D054465:Peroxiredoxin VI; C515983:Prdx6 protein, mouse; D053148:Caspase 3