There are a group of Japanese researchers who received approval from the government to put human stem cells into animal embryos. The hope is that they will one day be able to grow human organs in animals. They believe that if they are successful, there will be no need for people to be put on a donor list for organ transplants. They hope to be able to grow them in animals. Japanese scientists plan to create human-mouse hybrids. Here’s how.
Reversing the Ban
For years, the Japanese government had a ban on growing human cells in animal embryos beyond the 14th day of the existence of the embryo. There was also a ban on transplanting those embryos into the uterus of a surrogate animal. These things are banned in most parts of the world, but Japan decided to make a change.
Hiromitsu Nakuchi is a stem-cell biologist at Stanford University and the University of Tokyo. He has pursued this type of research for more than a decade and has been an advocate of having the ban lifted. He understood that lifting the ban could help bring about major breakthrough regarding organ transplant.
According to Nakuchi, he is just waiting for the final grant to be approved. If this happens, he can start moving forward with everything that he knows is possible. The first thing that he wants to do is to program a mouse and rat embryos not to grow in a pancreas. Instead, he will transfer the human iPS cells into those embryos. It is his hope that he will be able to develop a human pancreas in a rodent embryo.
The Next Step
If Nikuchi and his team are successful in the first stage, they hope to grow the embryos into full-fledged mice and rats. It will take them about two years to monitor the animals to make sure that everything is working well. According to the research team, this stage is critical. They won’t be able to complete this stage if Japan doesn’t approve the next phase in the project. This means changing the rules a bit.
Observing Is Essential
During the two year observation period, many of the laws that the government has put into place will need to be changed. If the scientists find human cells in more than 30 percent of the rodent brains, the experiment will need to stop immediately. The scientists need to make sure that a “humanized” animal won’t come into being.
What Is a Humanized Mouse
The term “humanized” is relatively vague. According to the researchers on the study, scientists are worried about what will happen if too many human cells creep into the mouse’s brain. It may sound like something from a science fiction movie, but it is possible that the mouse’s brain could have changes in cognition and mental ability in some way. The last thing that the scientists want is for the mice to start thinking and acting like humans. Some are worried that the mice will develop human-like features. This is the reason that Japan put the ban on the research in the first place. This is also the reason that the scientists will need to keep a very close eye on the rodents in the study.
An Early Experiment
Nakauchi believes that the scenario of a mouse starting to adapt human features is very unlikely. In a previous experiment, he put human iPS cells into a fertilized sheep egg. He later transplanted the embryo into a sheet at Stanford University. He says that the transplanted human cells didn’t cause the embryo into a crazy human-sheep creature. After 28 days, it was destroyed.
While the Japanese government and Nakuchi are sure that this research will bring about significant breakthroughs and save lives, there are others who are bringing up ethical questions. Anytime you take a species and mix it with another; you don’t know what will happen. This is why these processes are banned in countries all over the world. Nakuchi understands the ethical implications and plans to watch the study rodents. He wants to be successful in saving lives, but he is also going to be responsible.
The Hope For The Future
Nakuchi hopes that one day, we will be able to grow functioning human organs in an animal. If we can do this, people won’t die while waiting or a transplant. If a human needs an organ transplant, there will be plenty on hand. The hope of the study is that no person will ever have to die because there are no organs available. If Japan lifts the final ban, Nakuchi and his team will be that much closer to achieving their goal.