Kidney regeneration.

Neonephrogenesis, the capacity to regenerate renal tissue, is a distinctive feature of fish but not usually of mammals. However, evidence exists for kidney repair in response to insulting agents for animals and human beings. Studies have therefore been designed in the past few years to clarify the cellular and molecular basis of renal repair, with the aim to investigate the potential regenerative capacity of animal and human kidneys. Three main questions are being addressed by this research: whether terminally differentiated cells in adult animal kidneys have regenerative capacity; whether multipotent progenitor cells exist in kidneys; and whether renal repair can be favoured or accelerated by cells of extrarenal origin migrating to the kidney in response to injury. In this Review, we describe evidence of cellular and molecular pathways related to renal repair and regeneration, and review data from animal and human studies that show that the kidney might have regenerative capacity.