Aquaporin-11 (AQP11) Expression in the Mouse Brain.
Aquaporin-11 (AQP11) is an intracellular aquaporin expressed in various tissues, including brain tissues in mammals. While AQP11-deficient mice have developed fatal polycystic kidneys at one month old, the role of AQP11 in the brain was not well appreciated. In this study, we examined the AQP11 expression in the mouse brain and the brain phenotype of AQP11-deficient mice. AQP11 messenger ribonucleic acid (mRNA) and protein were expressed in the brain, but much less than in the thymus and kidney. Immunostaining showed that AQP11 was localized at the epithelium of the choroid plexus and at the endothelium of the brain capillary, suggesting that AQP11 may be involved in water transport at the choroid plexus and blood-brain barrier (BBB) in the brain. The expression of AQP4, another brain AQP expressed at the BBB, was decreased by half in AQP11-deficient mice, thereby suggesting the presence of the interaction between AQP11 and AQP4. The brain of AQP11-deficient mice, however, did not show any morphological abnormalities and the function of the BBB was intact. Our findings provide a novel insight into a water transport mechanism mediated by AQPs in the brain, which may lead to a new therapy for brain edema.
Division of Pathophysiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan. skoike@my-pharm.ac.jp.|Division of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan. skoike@my-pharm.ac.jp.
Shin
S
Koike
Division of Pathophysiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan. ystanaka@my-pharm.ac.jp.
Yasuko
Y
Tanaka
Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan. matoshi@gunma-u.ac.jp.
Toshiyuki
T
Matsuzaki
Division of Nephrology, Saitama Medical Center, Jichi Medical University, 1-847 Ohmiya, Saitama-City, Saitama 330-8503, Japan. ymori@jichi.ac.jp.
Yoshiyuki
Y
Morishita
Division of Pathophysiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan. kishiba@my-pharm.ac.jp.
Kenichi
K
Ishibashi
D000818:Animals; D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010539:Permeability; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
C503878:Aqp11 protein, mouse; D020346:Aquaporins; D012333:RNA, Messenger
AQP4; blood brain barrier; brain edema; choroid plexus; pia mater