This human-mouse chimera is the highest number of human cells ever recorded in an animal, according to researchers. Their experiment suggests that many types of human cells can be formed in mouse embryos, and at a faster rate than human embryos.
And that, say scientists, carries tremendous potential for the treatment of human diseases, possibly even Covid-19.
The findings have potential for treating the disease
These findings are important for many reasons, said Jian Feng, one of the study̵7;s authors and a professor of physiology and biophysics at the University of Buffalo.
For one, it has been shown that it is possible to produce many types of human mature cells in mouse embryos, which can then be used to make cells, tissues or organs to treat diseases.
In this study, the team of researchers injected 10 to 12 human stem cells into developing mouse embryos. Within 17 days, stem cells have evolved into millions of adherent cells, including red blood cells and stem cells.
In a human embryo, it takes about eight weeks to produce human red blood cells and even longer to produce human eye cells, Feng said.
“These observations suggest that the mechanism that determines the developmental time may be altered,” he wrote in an email to CNN. “With this hint, there will be even more dramatic discoveries along the way.”
The group used a revolutionary technology
In the previous research, scientists found only about 0.1% of human cells in mouse embryos.
That is why it is noteworthy that these human-mouse chimeras showed 4% human cells. And because of the technique the team used to count the cells, Feng said even that figure was a tiny bit.
The team achieved this task by converting pluripotent stem cells, which could potentially produce any cell or body tissue that had to repair itself, to a previous state.
Converting these cells makes them compatible with the inner group of cells within an early stage of the mouse embryo, which forms all the cells in the body. So if the early stages of human cells were injected into mouse embryos, they would have developed better than they would otherwise have.
“We hypothesize that if we can make pluripotent stem cells act like mouse pluripotent stem cells, human cells should interact well with mouse cells in a mouse blastocyst,” he wrote Feng. “And that’s exactly what we found.”
The team’s experiment suggests that “the genetic program contained in a mouse embryo and the genetic program embodied in human stem cells can crosstalk well,” Feng said.
In other words, there is sufficient evolutionary development between mice and humans that mouse embryos are a good environment for the cultivation of human cells.
“Life is a DNA-based software system that powers information production,” Feng wrote. “This experiment is kind of like Windows on a Mac.”
Implications for future organ development may be included
“The subjects of the Chimera test should be human enough to serve as effective models for health research, but not in humans that qualify them for protection from this research as a whole.”
Feng said their research is still in its stages and more studies need to be conducted. But he added that the technology of making human stem cells more compatible with mouse embryos has a number of potential applications.
One, Feng said, is that it can generate better mouse models to study human diseases, including Covid-19. Mice can also be used to grow human immune cells or respiratory cells.
“Such chimeric mice would be useful for the study of Covid-19, which severely affects humans, but only slightly affects mice,” Feng said.
“Another example could be malaria, in which the pathogen specifically infects red blood cells through a mosquito bite. If we can produce a mouse with more red blood cells, it would be a good model the study of malaria. “
Future studies could also explore whether this technique can be applied to larger animals, such as pigs, to produce organs for transplants, Feng said. Although he says those possibilities are far from over, they promise.
“At the time of the first plane, all the potential applications existed only in the minds of a few people,” Feng said. “If society decides it’s a horrible idea for people to fly, we will miss a lot of things that have been wonderful for everyone. A society that sees the world for what it is, not what it is what should be, is an effective society that can move forward. “