Anoctamins support calcium-dependent chloride secretion by facilitating calcium signaling in adult mouse intestine

Pflugers Arch. 2015 Jun;467(6):1203-13. doi: 10.1007/s00424-014-1559-2. Epub 2014 Jul 1.

Abstract

Intestinal epithelial electrolyte secretion is activated by increase in intracellular cAMP or Ca(2+) and opening of apical Cl(-) channels. In infants and young animals, but not in adults, Ca(2+)-activated chloride channels may cause secretory diarrhea during rotavirus infection. While detailed knowledge exists concerning the contribution of cAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) channels, analysis of the role of Ca(2+)-dependent Cl(-) channels became possible through identification of the anoctamin (TMEM16) family of proteins. We demonstrate expression of several anoctamin paralogues in mouse small and large intestines. Using intestinal-specific mouse knockout models for anoctamin 1 (Ano1) and anoctamin 10 (Ano10) and a conventional knockout model for anoctamin 6 (Ano6), we demonstrate the role of anoctamins for Ca(2+)-dependent Cl(-) secretion induced by the muscarinic agonist carbachol (CCH). Ano1 is preferentially expressed in the ileum and large intestine, where it supports Ca(2+)-activated Cl(-) secretion. In contrast, Ano10 is essential for Ca(2+)-dependent Cl(-) secretion in jejunum, where expression of Ano1 was not detected. Although broadly expressed, Ano6 has no role in intestinal cholinergic Cl(-) secretion. Ano1 is located in a basolateral compartment/membrane rather than in the apical membrane, where it supports CCH-induced Ca(2+) increase, while the essential and possibly only apical Cl(-) channel is CFTR. These results define a new role of Ano1 for intestinal Ca(2+)-dependent Cl(-) secretion and demonstrate for the first time a contribution of Ano10 to intestinal transport.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anoctamin-1
  • Anoctamins
  • Calcium / metabolism
  • Calcium Signaling*
  • Chloride Channels / genetics
  • Chloride Channels / metabolism*
  • Chlorides / metabolism*
  • Intestinal Mucosa / metabolism*
  • Mice
  • Organ Specificity
  • Phospholipid Transfer Proteins / genetics
  • Phospholipid Transfer Proteins / metabolism*

Substances

  • ANO1 protein, mouse
  • ANO6 protein, mouse
  • Anoctamin-1
  • Anoctamins
  • Chloride Channels
  • Chlorides
  • Phospholipid Transfer Proteins
  • Calcium