[Frontiers in Bioscience 13, 4451-4466, May 1, 2008]

Ciliary dysfunction in polycystic kidney disease: an emerging model with polarizing potential

Robert J. Kolb, Surya M. Nauli

Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, Department of Pharmacology and Medicine, College of Pharmacy and Medicine, University of Toledo, Toledo, OH, 43606


1. Abstract
2. Introduction
3. Inherited polycystic kidney diseases
4. Polycystins and fibrocystin expressions
4.1. Tissue distribution
4.2. Subcellular distribution
5. Primary Cilium
5.1. Biology of a primary cilium
5.2. Ciliary mechanosensation proteins
6. Planar cell polarity
7. Perspectives
8. Acknowledgement
9. References


The majority of different cell types in the human body have a cilium, a thin rod-like structure of uniquely arranged microtubules that are encapsulated by the surface plasma membrane. The cilium originates from a basal body, a mature centriole that has migrated and docked to the cell surface. The non-motile cilia are microtubule-based organelles that are generally considered sensory structures. The purpose of this review is to discuss the practicality of the ciliary hypothesis as a unifying concept for polycystic kidney disease and to review current literature in the field of cilium biology, as it relates to mechanosensation and planar cell polarity. The polycystins and fibrocystin localization at the cilium and other subcellular localizations are discussed, followed by a hypothetical model for the cilium's role in mechanosensing, planar cell polarity, and cystogenesis.