Animals do a lot for humans: nurture us with therapy, nourish us with food, and even test medicines for us. Now, scientists hope they’ll also let us use their organs, too.
Scientists in Japan say they have successfully used mice stem cells to grow kidneys in rat embryos. The report appearing Wednesday in Nature Communications journal says this method could one day be used to grow kidneys for human transplantation.
These prospects are delayed as “serious technical barriers” remain, they say. In addition, unresolved ethical concerns over stem cell research hamper wide support by the scientific community and public at large. Nevertheless, they note a dire shortage of donor kidneys in the world.
Pluripotent stem cells from mice — meaning mutable cells which can develop into any cell or tissue — were injected into rat embryos that had been genetically modified to not develop kidneys. They were then implanted into rat wombs and carried to term, and went on to produce functional kidneys.
(This method did not hold, however, when rat stem cells were injected into mice, but researchers still don’t exactly know why.)
Unfortunately, scientists were unable to monitor kidney function for long because the subjects died shortly after birth. An apparent mutation which removed their sense of smell prevented newborns from detecting their mother’s milk, and they starved.
As for harm to the animals, scientists are concerned that human stem cells in the “host” animal could develop into the wrong cells, such as brain or reproductive organs.
For now, researchers will turn to genetically modifying potential host rats to survive past infancy, and then will begin transplanting stem-cell derived kidneys to other animals. Eventually, scientists think this line of testing may lead to growing successful human organs, and they’re hopeful they’ll see it happen.
Masumi Hirabayashi, associate professor and study supervisor at Japan’s National Institute for Physiological Science, tells Yahoo! News, “I don’t know exactly the end of my lifetime — tomorrow? Thirty years? But I very much expect to hear news regarding the practical application of animal-hosted organs.”