Relevance of extracellular matrix, its receptors and cell adhesion molecules in mammalian nephrogenesis. Wallner, Elisabeth I., Qiwei Yang, Darryl R. Peterson, Jun Wada, and Yashpal S. Kanwar. Departments of Pathology* and Medicine, Northwestern University Medical School, Chicago, Illinois 60611
APStracts 5:0102F, 1998.
Mammalian nephrogenesis begins by the reciprocal interaction of the ureteric bud with the undifferentiated mesenchyme. The mesenchyme differentiates into an epithelial phenotype with the development of the glomerulus, and proximal and distal tubules. At the same time, the mesenchyme stimulates the branching morphogenesis of the ureteric bud that differentiates into the collecting ducts. These inductive interactions and differentiation events are modulated by a number of macromolecules, including the extracellular matrix, integrin receptors, and cell adhesion molecules. Many of these macromolecules exhibit spatio-temporal developmental regulation in the metanephros. Some are expressed in the mesenchyme, while others appear in the ureteric bud epithelia. The molecules expressed in the mesenchyme or at the epithelial:mesenchymal interface may serve as ligands while those in the epithelia as the receptors. In such a scenario the ligand and the receptor would be ideally suited for epithelial:mesenchymal paracrine/juxtacrine interactions that are also influenced by RGD sequences and Ca++ binding domains of the extracellular matrix proteins and their receptors. This review addresses the role of such interactions in metanephric development.

Received 21 May 1998; accepted in final form 22 May 1998.
APS Manuscript Number F127-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 16 June 1998