QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online May 15, 2009
Journal of Experimental Biology 212, 1753-1761 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.027284

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Shum, W. W. C. Articles by Breton, S. PubMed Articles by Shum, W. W. C. Articles by Breton, S. Social Bookmarking                         What's this?

Review Article

Regulation of luminal acidification in the male reproductive tract via cell–cell crosstalk

Winnie W. C. Shum, Nicolas Da Silva, Dennis Brown and Sylvie Breton^*

Center for Systems Biology, Program in Membrane Biology, Nephrology Division, Massachusetts General Hospital, Boston, MA 02114, USA and Harvard Medical School, Boston, MA 02115, USA

^* Author for correspondence (e-mail: sbreton{at}partners.org)

Accepted 6 January 2009

In the epididymis, spermatozoa acquire their ability to become motile and to fertilize an egg. A luminal acidic pH and a low bicarbonate concentration help keep spermatozoa in a quiescent state during their maturation and storage in this organ. Net proton secretion is crucial to maintain the acidity of the luminal fluid in the epididymis. A sub-population of epithelial cells, the clear cells, express high levels of the proton-pumping V-ATPase in their apical membrane and are important contributors to luminal acidification. This review describes selected aspects of V-ATPase regulation in clear cells. The assembly of a particular set of V-ATPase subunit isoforms governs the targeting of the pump to the apical plasma membrane. Regulation of V-ATPase-dependent proton secretion occurs via recycling mechanisms. The bicarbonate-activated adenylyl cyclase is involved in the non-hormonal regulation of V-ATPase recycling, following activation of bicarbonate secretion by principal cells. The V-ATPase is also regulated in a paracrine manner by luminal angiotensin II by activation of the angiotensin II type 2 receptor (AGTR2), which is located in basal cells. Basal cells have the remarkable property of extending long and slender cytoplasmic projections that cross the tight junction barrier to monitor the luminal environment. Clear cells are activated by a nitric oxide signal that originates from basal cells. Thus, a complex interplay between the different cell types present in the epithelium leads to activation of the luminal acidifying capacity of the epididymis, a process that is crucial for sperm maturation and storage.

Key words: H⁺-ATPase, pseudostratified epithelia, basal cells, clear cells

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JEB:

SOLUTE TRANSPORTERS AND ACID–BASE REGULATION

Kathryn Knight
JEB 2009 212: i. [Full Text]