Upregulation of aquaporin expression in the salivary glands of heat-acclimated rats.
It is known that aquaporin (AQP) 5 expression in the apical membrane of acinar cells in salivary glands is important for the secretion of saliva in rodents and humans. Although heat acclimation enhances saliva secretion in rodents, the molecular mechanism of how heat induces saliva secretion has not been determined. Here, we found that heat acclimation enhanced the expression of AQP5 and AQP1 in rat submandibular glands concomitant with the promotion of the HIF-1α pathway, leading to VEGF induction and CD31-positive angiogenesis. The apical membrane distribution of AQP5 in serous acinar cells enhanced after heat acclimation, while AQP1 expression was restricted to the endothelial cells in the submandibular glands. A network of AQPs may be involved in heat-acclimated regulation in saliva secretion. Because AQPs probably plays a crucial role in saliva secretion in humans, these findings may lead to a novel strategy for treating saliva hyposecretion.
1] Department of Physiology, Graduate School of Medical Science, Kanazawa University [2] Department of Environmental Physiology, School of Medicine, Shimane University.
Naotoshi
N
Sugimoto
Kentaro
K
Matsuzaki
Hiroaki
H
Ishibashi
Masao
M
Tanaka
Toshioki
T
Sawaki
Yoshimasa
Y
Fujita
Takafumi
T
Kawanami
Yasufumi
Y
Masaki
Toshiro
T
Okazaki
Joji
J
Sekine
Shoichi
S
Koizumi
Akihiro
A
Yachie
Hisanori
H
Umehara
Osamu
O
Shido
D000064:Acclimatization; D000818:Animals; D051398:Aquaporin 1 / Q000235:genetics* / Q000378:metabolism; D051402:Aquaporin 5 / Q000235:genetics* / Q000378:metabolism; D001835:Body Weight; D015687:Cell Hypoxia; D005347:Fibroblasts / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008297:Male; D051379:Mice; D041681:NIH 3T3 Cells; D009929:Organ Size; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013363:Submandibular Gland / Q000098:blood supply / Q000166:cytology / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
C496022:Aqp1 protein, rat; C496040:Aqp5 protein, rat; D051402:Aquaporin 5; D006360:Heat-Shock Proteins; C497444:Hif1a protein, rat; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D051398:Aquaporin 1