Aquaporin expression in the brains of patients with or without cerebral amyloid angiopathy.
Aquaporins have recently been identified as protein channels involved in water transport. These channels may play a role in the edema formation and alterations in microvascular function observed in Alzheimer disease (AD) and cerebral amyloid angiopathy (CAA). We investigated the expression of aquaporin 1 (AQP1) and aquaporin 4 (AQP4) in 24 human autopsy brains consisting of 18 with AD and varying degrees of CAA and 6 with no pathologic abnormalities using immunohistochemistry. In cases of AD and CAA, there was enhanced AQP4 expression compared with the age- and sex-matched controls. Aquaporin 4 immunoreactivity was prominent at the cerebrospinal fluid and brain interfaces, including subpial, subependymal, pericapillary, and periarteriolar spaces. Aquaporin 1 expression in AD and CAA cases was not different from that in age- and sex-matched controls. Double labeling studies demonstrated that both AQP1 and 4 were localized to astrocytes. Both enhanced AQP4 expression and its unique staining pattern suggest that these proteins may be important in the impaired water transport observed in AD and CAA.
Department of Radiology & Biomedical Imaging, UCSF Medical Center, San Francisco, CA, USA.
Parham
P
Moftakhar
Matthew D
MD
Lynch
Justine L
JL
Pomakian
Harry V
HV
Vinters
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology; D051398:Aquaporin 1 / Q000096:biosynthesis*; D051401:Aquaporin 4 / Q000096:biosynthesis*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D016657:Cerebral Amyloid Angiopathy / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male
D051401:Aquaporin 4; D051398:Aquaporin 1