The bile acid-sensitive ion channel (BASIC) mediates bile acid-dependent currents in bile duct epithelial cells

Pflügers Archiv - European Journal of Physiology, vol. 473, pp. 1841–1850

Abstract

Abstract The bile acid-sensitive ion channel (BASIC) is a member of the Deg/ENaC family of ion channels that is activated by bile acids. Despite the identification of cholangiocytes in the liver and unipolar brush cells in the cerebellum as sites of expression, the physiological function of BASIC in these cell types is not yet understood. Here we used a cholangiocyte cell line, normal rat cholangiocytes (NRCs), which expresses BASIC to study the role of the channel in epithelial transport using Ussing chamber experiments. Apical application of bile acids induced robust and transient increases in transepithelial currents that were carried by Na+ and partly blocked by the BASIC inhibitor diminazene. Genetic ablation of the BASIC gene in NRC using a CRISPR-cas9 approach resulted in a decrease of the bile acid-mediated response that matched the diminazene-sensitive current in NRC WT cells, suggesting that cholangiocytes respond to bile acids with a BASIC-mediated Na+ influx. Taken together, we have identified BASIC as a component of the cholangiocyte transport machinery, which might mediate a bile acid-dependent modification of the bile and thus control bile flux and composition.

Authors 4

1. Shari Wiegreffe Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany

2. Daniel Löhrer Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany

3. Monika Wirtz Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany

4. Dominik Wiemuth corresponding Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany. dwiemuth@ukaachen.de

   Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany