This review focuses on various components of bile acid signaling in relation to cholangiocytes. Their roles as targets for potential therapies for cholangiopathies are also explored. While many factors are involved in these complex signaling pathways, this review emphasizes the roles of transmembrane G protein coupled receptor (TGR5), farnesoid X receptor (FXR), ursodeoxycholic acid (UDCA) and the bicarbonate umbrella. Following a general background on cholangiocytes and bile acids, we will expand the review and include sections that are most recently known (within 5-7 years) regarding the field of bile acid signaling and cholangiocyte function. These findings all demonstrate that bile acids influence biliary functions which can, in turn, regulate the cholangiocyte response during pathological events.
Keywords: ABCB4, ATP-binding cassette, sub-family B; AE2, anion exchanger 2; AKT, protein kinases B; ASBT, apical sodium bile acid transporter; BA, bile acid; BASIC, bile acid sensitive ion channel; Bile acids; COX-2, cyclooxygenase-2; CYP27, sterol-27-hydroxylase; CYP7A1, cholesterol 7α-hydroxylase; Ca2+, intracellular calcium; Cholangiocytes; Cl−/HCO3−, chloride bicarbonate exchanger; EGFR, epidermal growth factor receptor; ERK, extracellular regulated protein kinases; FGF, fibroblast growth factor; FXR, farnesoid X receptor; HGF, hepatocyte growth factor; IL-6, interleukin-6; MAPK, mitogen-activated protein kinase; OST, organic solute transporter; PBC, primary biliary cirrhosis; PC-1, polycystin-1; PM, plasma membrane; PSC, primary sclerosing cholangitis; Receptors; S1P, sphingosine-1-phosphate; S1PR2, sphingosine 1-phosphate receptor 2; SR, secretin receptor; Signaling; TCA, taurocholic acid; TGR5, transmembrane G protein coupled receptor; UDCA, ursodeoxycholic acid.