Skip Navigation


NDT Advance Access originally published online on January 25, 2005
Nephrology Dialysis Transplantation 2005 20(3):509-515; doi:10.1093/ndt/gfh677
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
20/3/509    most recent
gfh677v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (9)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Kasono, K.
Right arrow Articles by Ishikawa, S.-e
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kasono, K.
Right arrow Articles by Ishikawa, S.-e
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author [2005]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oupjournals.org

Original Article

Hypertonicity regulates the aquaporin-2 promoter independently of arginine vasopressin

Keizo Kasono1,3, Tomoyuki Saito1, Takako Saito1, Hiroyuki Tamemoto1, Chieko Yanagidate1, Shinichi Uchida2, Masanobu Kawakami1, Sei Sasaki2 and San-e Ishikawa1

1 Department of Medicine, Jichi Medical School, Omiya Medical Center, Saitama, 2 Department of Nephrology, Graduate School, School of Medicine, Tokyo Medical and Dental University, Tokyo and 3 Laboratory of Clinical Nutrition, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan

Correspondence and offprint requests to: San-e Ishikawa, MD, Department of Medicine, Jichi Medical School, Omiya Medical Center, 1-847 Amanuma, Omiya-ku, Saitama, Saitama 330-8503, Japan. E-mail: saneiskw{at}jichi.ac.jp

Background. Aquaporin-2 (AQP-2) is an arginine vasopressin (AVP)-regulated water channel in kidney collecting duct cells. The present study was undertaken to determine whether a change in tonicity could directly regulate the AQP-2 gene in an in vitro experiment.

Methods. Various fragments of the 5'-flanking region of the murine AQP-2 gene up to –9.5 kb were cloned into a luciferase (Luc) reporter plasmid, and they were transiently transfected into Madin–Darby canine kidney cells.

Results. Hypertonicity significantly increased the Luc activity of the constructs containing >6.1 kb of the 5'-flanking region of the AQP-2 gene (–6.1AQP2). However, promoter regions <4.3 kb in length containing the tonicity-responsive enhancer (TonE) at bp –570 to –560 were not stimulated by hypertonicity. The TonE-deleted construct which contains –9.5 to –1.1 kb of the 5' side of the AQP-2 gene, 8.4AQP2, was also stimulated by hypertonicity. Mitogen-activated protein (MAP) kinase inhibitors SB203580 and U0126 did not affect the Luc activity of –6.1AQP2 induced by hypertonicity. In addition, the vector expressing dominant-negative TonE-binding protein (TonEBP) did not affect the hypertonicity-induced Luc activity of –6.1AQP2. The Luc activity of –6.1AQP2 was stimulated by the overexpression of TonEBP. Hypertonicity further increased the Luc activity of –6.1AQP2 under the overexpression of TonEBP.

Conclusion. These findings indicate that hypertonicity regulates AQP-2 promoter activity via an AVP-independent mechanism, and that the tonicity-responsive element resides between the –6.1 and –4.3 kb 5'-flanking region of the AQP-2 gene, in which the structure and mechanism of response to hypertonicity could be distinct from those of TonE.

Keywords: aquaporin-2; gene regulation; hypertonicity; kidney; tonicity-responsive enhancer


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
S.-Z. Li, B. W. McDill, P. A. Kovach, L. Ding, W. Y. Go, S. N. Ho, and F. Chen
Calcineurin-NFATc signaling pathway regulates AQP2 expression in response to calcium signals and osmotic stress
Am J Physiol Cell Physiol, May 1, 2007; 292(5): C1606 - C1616.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
J. H. Robben, N. V. A. M. Knoers, and P. M. T. Deen
Cell biological aspects of the vasopressin type-2 receptor and aquaporin 2 water channel in nephrogenic diabetes insipidus.
Am J Physiol Renal Physiol, August 1, 2006; 291(2): F257 - F270.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.