Published online Nov 28, 2019. doi: 10.3748/wjg.v25.i44.6483
Peer-review started: August 18, 2019
First decision: October 14, 2019
Revised: October 22, 2019
Accepted: November 13, 2019
Article in press: November 13, 2019
Published online: November 28, 2019
The liver is a complex organ that performs several functions to maintain homeostasis. These functions are modulated by calcium, a second messenger that regulates several intracellular events. In hepatocytes and cholangiocytes, which are the epithelial cell types in the liver, inositol 1,4,5-trisphosphate (InsP3) receptors (ITPR) are the only intracellular calcium release channels. Three isoforms of the ITPR have been described, named type 1, type 2 and type 3. These ITPR isoforms are differentially expressed in liver cells where they regulate distinct physiological functions. Changes in the expression level of these receptors correlate with several liver diseases and hepatic dysfunctions. In this review, we highlight how the expression level, modulation, and localization of ITPR isoforms in hepatocytes and cholangiocytes play a role in hepatic homeostasis and liver pathology.
Core tip: Calcium regulates a variety of functions in our body. In the liver, inositol 1,4,5-trisphosphate receptors (ITPR) are the only expressed intracellular calcium release channels. ITPR regulates liver functions under healthy situation, but they can also be involved in liver diseases, depending for instance, in which isoform is expressed in a specific cell type, level of expression and where inside the cell each isoform is expressed. In this review, we discuss about ITPR roles in hepatic cells in physiological and pathological conditions.