Identification of progenitors capable of kidney regeneration in zebrafish

Unlike adult mammals, which can repair but not regenerate new nephrons, fish generate nephrons de novo throughout life and after kidney injury. To explore mechanisms of kidney regeneration that could one day be applied to treat renal disease in humans, Diep et al. used the zebrafish as a model to identify and characterise progenitor cells responsible for nephron regeneration. Using transplantation experiments, they traced the source of new adult nephrons back to small aggregates of cells containing kidney progenitors. As previously found for mouse nephrons, individual zebrafish nephrons are derived from multiple nephron progenitors, which the authors suggest have self-renewing properties. Furthermore, gene-expression analyses indicated conservation between mammals and zebrafish with respect to the factors involved in renal development. These results provide hope that nephron progenitors with self-renewing potential might also be present in the human adult kidney and could be coaxed out of a dormant state to stimulate kidney regeneration following injury or disease. S.A.