Aquaporin 4 (AQP4), the most abundant water channel protein in the brain, is involved in brain edema induced by ischemic insults. To evaluate whether the neuroprotective effects of estrogen are associated with AQP4 expression and edema formation, changes in AQP levels and ischemic edema were examined in the brains of male and female mice subjected to transient middle cerebral artery occlusion. Infarct volume and edema formation were markedly less in females than in males. AQP4 expression in the ischemic cortex of females was relatively well preserved, whereas it was significantly decreased in males. These effects disappeared in ovariectomized females but were reversed by estrogen replacement. Furthermore, AQP4 expression was decreased with increased brain edema in females treated with ICI182,780, an estrogen receptor antagonist. These findings suggest that the estrogen effect on the reduction of ischemic brain edema is associated with the preserved level of AQP4 that is partly mediated by estrogen receptors.
|Number of pages
|Biochimica et Biophysica Acta - Molecular Basis of Disease
|Published - Sep 2011
Bibliographical noteFunding Information:
This work was supported by the Korea Research Foundation Grant funded by the Korean Government ( KRF-2008-331-E00055 ) to E.M.P. and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2010–0029352 ) to J.H.C.
- Aquaporin 4
- Brain edema
- Estrogen receptor
- Ischemic stroke
- Sex difference