A team of researchers has succeeded in regenerating kidneys in rats using the developmental stage of organs in the fetal period.
The group was able to regenerate completely formed kidneys equipped with typical functions such as urine production -- which is a promising step in terms of future clinical application in humans.
The team, which includes members of the Jikei University School of Medicine, has recently released its findings in the British scientific journal Nature Communications.
In its research, the team members created genetically modified mouse fetuses. At the "buds" of the fetuses' kidneys, the team injected precursor cells that go on to become rat kidneys, before transplanting the buds to other rats possessing the same genetic information.
The rats were later administered a special drug, which caused the mice precursor cells -- that were initially at the buds -- to die out. Blood vessels began to emerge from the surrounding tissue in the buds, and four weeks later, regenerated kidneys consisting solely of rat cells were formed. It was confirmed that the kidneys possessed standard functions such as urine production.
In addition, the team is also working on enabling rats to excrete urine out of its bodies using a regenerated ureter. The researchers also aim to finalize a process whereby kidney precursor cells can be created from human induced pluripotent stem (iPS) cells.
If kidney buds from a pig fetus can be used instead of those of mice and precursor kidney cells made from iPS cells from a patient with kidney failure used instead of those of rats, it might be possible to regenerate a perfectly functioning human kidney.
"Once the kidneys were regenerated, immunosuppressants were no longer necessary. I want to proceed with research in humans, and aim toward carrying out heterologous (cross-species) transplants with regenerated kidneys," said team member and Jikei University professor Takashi Yokoo.