Cystic kidney disease: the role of Wnt signaling.

Wnt signaling encompasses a variety of signaling cascades that can be activated by secreted Wnt ligands. Two such pathways, the canonical or beta-catenin pathway and the planar cell polarity (PCP) pathway, have recently received attention for their roles in multiple cellular processes within the kidney. Both of these pathways are important for kidney development as well as homeostasis and injury repair. The disruption of either pathway can lead to cystic kidney disease, a class of genetic diseases that includes the most common hereditary life-threatening syndrome polycystic kidney disease (PKD). Recent evidence implicates canonical and noncanonical Wnt pathways in cyst formation and points to a remarkable role for developmental processes in the adult kidney.