OKAZAKI, Japan — The idea of lab-grown organs being used to save human lives sounded more like science fiction than reality just a few decades ago, but new research out of Japan suggests man-made organs may be a viable option for patients in need in the not so distant future.
Researchers from the National Institute for Physiological Sciences in Okazaki, Japan successfully grew functional mouse kidneys inside rats using only a few donor stem cells, potentially paving the way for humans to one day benefit from lab-grown kidneys.
All of this is especially relevant to end-stage renal disease patients in need of kidney transplants. Many renal patients never receive the kidney transplant they need due to a worldwide shortage of donor kidneys. For example, in just the United States alone there are currently 95,000 people waiting for a donor kidney.
For this experiment, researchers used a method that has already shown promising results in the past, called blastocyst complementation. During this process, scientists take the clusters of cells formed shortly after fertilization, that will eventually develop into a fetus, from deformed animals that are missing certain organs. These cell clusters are then injected with stem cells from a healthy donor. The healthy donor doesn’t have to necessarily be from the same species, just as in this case mouse stem cells were used on rats.
After injection, these stem cells assimilate themselves to their new surroundings and form the entire missing organ in the new animal. The newly grown organ retains the characteristics of its original stem cell donor, making it eligible to be used in a transplant.
“We previously used blastocyst complementation to generate rat pancreas in apancreatic mutant mice,” explains lead study author Teppei Goto in a statement. “We therefore decided to investigate whether the method could be used to generate functional kidneys, which would have much greater application in regenerative medicine owing to the high donor demand.”
When researchers injected pseudo-pregnant rats with mouse stem cells, the resulting fetuses all developed normally. More than two-thirds of the resulting rat babies contained two mouse kidneys, and all of those kidneys were shown to be structurally correct and at least half could potentially create urine.
“Our findings confirm that interspecific blastocyst complementation is a viable method for kidney generation,” says corresponding author Masumi Hirabayashi. “In the future, this approach could be used to generate human stem cell-derived organs in livestock, potentially extending the lifespan and improving the quality of life of millions of people worldwide.”