Uromodulin Regulates Murine Aquaporin−2 Activity via Thick Ascending Limb–Collecting Duct Cross−Talk during Water Deprivation

Autor: Tomoaki Takata, Shintaro Hamada, Yukari Mae, Takuji Iyama, Ryohei Ogihara, Misako Seno, Kazuomi Nakamura, Miki Takata, Takaaki Sugihara, Hajime Isomoto
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: International Journal of Molecular Sciences; Volume 23; Issue 16; Pages: 9410
ISSN: 1422-0067
DOI: 10.3390/ijms23169410
Popis: Uromodulin, a urinary protein synthesized and secreted from the thick ascending limb (TAL) of the loop of Henle, is associated with hypertension through the activation of sodium reabsorption in the TAL. Uromodulin is a potential target for hypertension treatment via natriuresis. However, its biological function in epithelial cells of the distal nephron segment, particularly the collecting duct, remains unknown. Herein, we examined the regulation of uromodulin production during water deprivation in vivo as well as the effect of uromodulin on the activity of the water channel aquaporin−2 (AQP2) in vitro and in vivo using transgenic mice. Water deprivation upregulated uromodulin production; immunofluorescence experiments revealed uromodulin adhesion on the apical surface of the collecting duct. Furthermore, the activation of AQP2 was attenuated in mice lacking uromodulin. Uromodulin enhanced the phosphorylation and apical trafficking of AQP2 in mouse collecting duct cells treated with the vasopressin analog dDAVP. The uromodulin-induced apical trafficking of AQP2 was attenuated via endocytosis inhibitor treatment, suggesting that uromodulin activates AQP2 through the suppression of endocytosis. This study provides novel insights into the cross−talk between TAL and the collecting duct, and indicates that the modulation of uromodulin is a promising approach for diuresis and hypertension treatment.
Databáze: OpenAIRE
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