Roles of growth factors in renal development.

The branching of the ureteric bud and the differentiation of renal mesenchyme into nephrons are interdependent processes. Experiments with organ culture and genetically engineered mice suggest that metanephric growth factors regulate these events. Renal mesenchyme produces glial cell line-derived neurotrophic factor, an essential molecule for ureteric bud growth, whereas multiple growth factors are required for nephron formation: these include fibroblast growth factor 2, Wnt4 and bone morphogenetic protein 7. Deregulation of growth factors may be implicated in the pathogenesis of congenital kidney malformations.