Apoptosis and the kidney.

Apoptosis is a programmed form of cell death mediating the precisely controlled deletion of "unwanted" cells. This review discusses the key features of this cell death program, emphasizing that apoptosis is regulated by factors extrinsic and intrinsic to the dying cell. Furthermore, because apoptosis leads to the swift phagocytic clearance of intact cells, tissues are protected against the noxious effect of cell contents. Apoptosis occurs in the developing and adult kidney, and nephrologists now need to consider whether abnormalities of this program may contribute to renal disease. Evidence suggests that such defects could contribute to developmental abnormalities including polycystic disease, induce autoimmunity to renal tissue, and exacerbate renal inflammation and scarring. Finally, apoptosis may offer new avenues for therapy.