Human aquaporins : regulators of transcellular water flow

Research output: Contribution to journalArticle

Authors

  • Rebecca E. Day
  • Philip Kitchen
  • David S. Owen
  • Charlotte Bland
  • Lindsay Marshall
  • Roslyn M. Bill
  • Matthew T. Conner

Colleges, School and Institutes

Abstract

Background
Emerging evidence supports the view that (AQP) aquaporin water channels are regulators of transcellular water flow. Consistent with their expression in most tissues, AQPs are associated with diverse physiological and pathophysiological processes.

Scope of review
AQP knockout studies suggest that the regulatory role of AQPs, rather than their action as passive channels, is their critical function. Transport through all AQPs occurs by a common passive mechanism, but their regulation and cellular distribution varies significantly depending on cell and tissue type; the role of AQPs in cell volume regulation (CVR) is particularly notable. This review examines the regulatory role of AQPs in transcellular water flow, especially in CVR. We focus on key systems of the human body, encompassing processes as diverse as urine concentration in the kidney to clearance of brain oedema.

Major conclusions
AQPs are crucial for the regulation of water homeostasis, providing selective pores for the rapid movement of water across diverse cell membranes and playing regulatory roles in CVR. Gating mechanisms have been proposed for human AQPs, but have only been reported for plant and microbial AQPs. Consequently, it is likely that the distribution and abundance of AQPs in a particular membrane is the determinant of membrane water permeability and a regulator of transcellular water flow.

General significance
Elucidating the mechanisms that regulate transcellular water flow will improve our understanding of the human body in health and disease. The central role of specific AQPs in regulating water homeostasis will provide routes to a range of novel therapies. This article is part of a Special Issue entitled Aquaporins.

Details

Original languageEnglish
Pages (from-to)1492-1506
JournalBiochimica et Biophysica Acta (BBA) - General Subjects
Volume1840
Issue number5
Early online date30 Sep 2013
Publication statusPublished - 1 May 2014

Keywords

  • Aquaporin regulation, Transcellular water flow, Homeostasis, Cell volume regulation, Regulatory volume increase, Regulatory volume decrease