Renal Stem Cell Biology Starts to Take Spherical Shape Commentary on: Lusis et al., Isolation of clonogenic, long-term self renewing embryonic renal stem cells

The nephron is the fundamental unit of renal function, yet the ability of the kidney to regenerate nephrons after birth is limited. Due to the medical and financial impact of chronic and end stage renal disease, an improved understanding of nephron formation is necessary if regenerative or cell therapy are to be a feasible alternative to dialysis or renal transplant. In the study presented by Lusis et al., the presence of metanephric mesenchymal stem cells is definitively demonstrated. However, these "Nephrospheres" have characteristics of mesenchynnal stem cells and substantially lack the ability to undergo an epithelial-to-mesenchyme transition or to form epithelial elements otherwise necessary for building the constituent cells of the nephron. Nevertheless, this newly isolated cell population opens many opportunities to investigate the consequences of normal and aberrant nephrogenesis, including Wilms tumor. (C) 2010 Published by Elsevier B.V.