Los kidneys contain 50-60% of human cells and grew normally in the animals until gestation was terminated at 25-28 days. This experiment, which is published in Cell Stem Cell, demonstrates the feasibility of culturing a solid human organ inside another species. The researchers not only successfully achieved the chimeras but also showed that the kidneys grew with a normal structure.
This experiment involves a scientific milestone. Those responsible are a team of researchers from the University of Canton, in China. “Our study shows that solid human organs such as the kidney can grow in pig embryos and this is very exciting, because the implications are immense”, the Spanish immunologist writes to this outlet from China Miguel A. Esteban, who is one of the lead authors of the study.
The implications to which the scientist alludes are an old medicine dream to find formulas that allow “growing” in animals human organs available for transplantation.
The integration of cells of different species has been an important barrera in those investigations. Now this team of scientists from the Guangdong Institutes of Biomedicine and Health of the Chinese Academy of Sciences has overcome it with a procedure that includes the CRISPR gene editing technique. With it, they eliminated two genes necessary for the kidney to form in the porcine embryo, and in this way they created a kind of niche so that human cells did not have to compete with porcine ones.
Then they prepared human pluripotent stem cells to which they administered factors that favored their survival and that they cultivated in an optimized medium, until they achieved human embryo-like cells. Once integrated into the pig embryos, they grew those chimeras under optimal conditions of nutrients and specific signals for both human and pig cells, and finally implanted the embryos in the sows.