Renal disease is a major worldwide public health problem that affects one in ten people.
Renal failure is caused by the irreversible loss of the structural and functional units of kidney (nephrons)
due to acute and chronic injuries. In humans, new nephrons (nephrogenesis) are generated until
the 36th week of gestation and no new nephron develops after birth. However, in rodents, nephrogenesis
persists until the immediate postnatal period. The postnatal mammalian kidney can partly repair
their nephrons. The kidney uses intrarenal and extra-renal cell sources for maintenance and repair.
Currently, it is believed that dedifferentiation of surviving tubular epithelial cells and presence of resident
stem cells have important roles in kidney repair. Many studies have shown that stem cells obtained
from extra-renal sites such as the bone marrow, adipose and skeletal muscle tissues, in addition
to umbilical cord and amniotic fluid, have potential therapeutic benefits. This review discusses the
main mechanisms of renal regeneration by stem cells after a kidney injury.