Research Provides Ways to Address Organ Shortage: Here's Everything You Need to Know

Tokyo: With a handful of donor stem cells, a team of Japanese researchers has developed functional mouse kidneys in rats, an advance that could address the chronic shortage of donor kidneys worldwide.

The new kidneys appeared to be functional and validated the proof of concept that this approach could be used to generate human kidneys in livestock, according to the study that will be published in the next Nature Communications Journal.

For patients with end-stage renal failure, kidney transplant is the only hope of returning to a quality life. But many patients never get a transplant because of a chronic shortage of donor kidneys. The researchers also worked on ways to develop healthy organs outside the human body.

One of these methods, complementation of the blastocyst, gave promising results for rat pancreas generation in apancreatic mutant mice. Researchers at the National Institute of Physiological Sciences of Japan have decided to study the possibility of using this method to generate functional kidneys, which would be much more widely applied in regenerative medicine because of the high demand for donors.

The team's initial attempts to grow the rat kidneys were unsuccessful, since rat stem cells did not readily differentiate into two main types of cells required for kidney formation. However, when the reverse scenario was attempted, mouse stem cells differentiated efficiently inside rat blastocysts, thus forming the basic structures of a kidney.

After implantation in pseudopregnant rats, complemented blastocysts became normal fetuses. Remarkably, more than two-thirds of the newborns in rats contained a pair of kidneys derived from mouse stem cells.

Further examination showed that all the kidneys were structurally intact and that at least half of them could potentially produce urine. "Our results confirm that interspecific complementation of blastocysts is a viable method for kidney generation," said Masumi Hirabayashi, of the university.

"This approach could be used to generate organs derived from human stem cells in cattle, potentially extending the lifespan and improving the quality of life for millions of people around the world," said Hirabayashi.