NDT Advance Access published online on January 25, 2005
Nephrology Dialysis Transplantation, doi:10.1093/ndt/gfh677
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, Jichi Medical School, Omiya Medical Center, Saitama, Japan; Laboratory of Clinical Nutrition, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan
* To whom correspondence should be addressed. 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.
Received June 14, 2004
Accepted December 8, 2004
Original Articles
Hypertonicity regulates the aquaporin-2 promoter independently of arginine vasopressin
2 Department of Medicine, Jichi Medical School, Omiya Medical Center, Saitama, Japan
3 Department of Nephrology, Graduate School, School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
San-e Ishikawa, E-mail: saneiskw{at}jichi.ac.jp
Abstract 
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  U. Hasler Controlled aquaporin-2 expression in the hypertonic environment Am J Physiol Cell Physiol, April 1, 2009; 296(4): C641 - C653. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Izumi, Y. Nakayama, H. Memetimin, T. Inoue, Y. Kohda, H. Nonoguchi, and K. Tomita Regulation of V2R transcription by hypertonicity and V1aR-V2R signal interaction Am J Physiol Renal Physiol, October 1, 2008; 295(4): F1170 - F1176. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Saito, T. Saito, K. Kasono, H. Tamemoto, M. Kawakami, S. Sasaki, and S.-e Ishikawa Hypotonicity reduces the activity of murine aquaporin-2 promoter induced by dibutyryl cAMP Exp Physiol, October 1, 2008; 93(10): 1147 - 1156. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
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]
|
|