Regeneration and the kidney

Abstract

Following any injury, various intracellular and intercellular pathways must be activated and coordinated if tissue integrity and homeostasis need to be restored. In most injuries, repair results in once-functional tissue becoming a patch of cells and disorganized extracellular matrix that is referred to as a scar. However, most adult organs of the body, including the kidney, have the potential to regenerate functional tissues if appropriate conditions are restored. In this review, we highlight the burst of recent knowledge leading to discovery of regenerative mechanisms also in adult kidneys. A large body of evidence has recently shown that the parietal epithelium of the Bowman's capsule represents a reservoir of renal progenitors in adult kidney. The discovery of a hierarchical population of renal progenitors within the Bowman's capsule which can generate novel podocytes and also proximal tubular cells provides a new point of view for the understanding of renal physiology. In addition, the observation that renal progenitors can also generate hyperplastic glomerular lesions opens up a novel view of the pathogenesis of different types of glomerular disorders, which may at least in part result from abnormal regenerative responses to podocyte injury.