Cholangiocyte biology.

Cholangiocytes are of considerable intrinsic biologic interest, particularly with regard to their roles in the transport of water, ions, and solutes, and to their heterogeneity and proliferative capacity. Cholangiocytes represent an important target of study in the cholangiopathies, a group of genetic developmental and acquired diseases of the liver. New biologic concepts continue to evolve through the use of experimental models (eg, knockout mice and selective gene silencing) and enhanced approaches to three-dimensional modeling and microscopy. The role of the cholangiocyte cytoskeleton in transport and intracellular trafficking has been recently recognized. These paradigms provide a framework for further understanding the mechanisms modulating normal cholangiocyte growth, transport, and signaling, and the abnormalities that result in disease.