15 - Establishment of Polarity in Epithelial Cells of the Developing Nephron

Abstract

This chapter describes the components of a polarized renal epithelial cell, the mechanisms by which they are established and maintained, and what is known of the developmental aspects of this process. Establishment of these surface membrane apical and basolateral domains is a multistage process involving cell–cell and cell–extracellular matrix (ECM) interactions, together with multiple intracellular targeting steps. These dynamic events require the proper organization of the cytoskeleton in general and the actin cytoskeleton in particular. Any alteration that disrupts the polarity of the surface membrane domains will prevent normal cell function and may result in organ dysfunction and potentially a disease state. With the availability of new developmental techniques and the tremendous growth in the understanding of the establishment and maintenance of epithelial polarity elsewhere, substantial progress should soon be made in the understanding of this aspect of kidney development and function. Of particular importance here are new data regarding protein scaffolds and their potential role in mediating the establishment of polarity in developing epithelial cells of the nephron.