title: Loss of AQP4 polarized localization with loss of β-dystroglycan immunoreactivity may induce brain edema following intracerebral hemorrhage.
abstract: The aquaporin-4 (AQP4) water channel contributes to brain water homeostasis in perivascular and subpial membrane domains of astrocytes where it is concentrated. These membranes form the interface between the neuropil and the extracellular liquid spaces. The brain-selective deletion of the dystroglycan (DG) gene causes a disorganization of AQP4 on the astroglial endfeet. First, we analyzed the expression of AQP4, β-DG in the brain following intracerebral hemorrhage (ICH) and correlated AQP4 expression with the expression pattern of the β-DG, which is a component of dystrophin-dystroglycan complex (DDC). Besides, the vessels ultrastructure and brain water content were investigated at different time points post-ICH (day 1, day 3, day 7). We found that AQP4 polarity was disturbed in parallel with the loss of β-DG in the perihematomal area post-ICH. At day 1 post-ICH, brain edema was obvious and the damage of vascular ultrastructure was the most severe. These results suggest a role for β-DG in targeting and stabilizing AQP4 channel in astrocytic cells, which may be critical for water homeostasis in brain.
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Qiu
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhuo
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China. Electronic address: sunsq2151@cqmu.edu.cn.
authors.forename: Shan-Quan
authors.initials: SQ
authors.lastname: Sun
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Huang
authors.affiliation: Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Wei-Tian
authors.initials: WT
authors.lastname: Lu
authors.affiliation: Traditional Chinese Medical College, Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Si-Qin
authors.initials: SQ
authors.lastname: Huang
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000378:metabolism / Q000648:ultrastructure; D001921:Brain / Q000098:blood supply / Q000648:ultrastructure; D001929:Brain Edema / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D049030:Dystroglycans / Q000378:metabolism*; D008297:Male; D017207:Rats, Sprague-Dawley
chemical_list: C496032:Aqp4 protein, rat; D051401:Aquaporin 4; D049030:Dystroglycans
keywords: Aquaporin-4; Brain edema; Intracerebral hemorrhage; Polarity; β-Dystroglycan