Researchers produce expanded potential stem cells (EPSCs)

An international research group produces highly potent cells from humans and pigs. The researchers see new possibilities for regenerative medicine.

Scientists speak of a "breakthrough"

An international research group produces highly potent cells from humans and pigs. The researchers see new possibilities for regenerative medicine.

Scientists use the word "breakthrough" with extreme caution when referring to their research results. This also applies to Professor Dr. Heiner Niemann, honorary professor at the Hanover Medical School (German acronym: MHH) and until August 2018 head of the Institute of Farm Animal Genetics (German acronym ING) at the Friedrich Loeffler Institute for Animal Health (also known as the Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit). For the first time, an international research group from Germany, Great Britain, and China has succeeded in producing a particularly versatile type of stem cells in pigs and humans and multiplying them under laboratory conditions. Using a special nutrient solution, the scientists have succeeded in producing a particularly viable cell type: embryonic stem cell lines with enhanced potential (EPSC). The results were published in the journal Nature Cell Biology.

Stem cells with greater development potential

"The EPSC we produce is something very special because it has a greater development potential than normal embryonic stem cells," said Professor Niemann. "They can not only develop into all cell types but can also form extraembryonic tissue that surrounds the embryo and later forms essential parts of the placenta - the trophoblasts. Previously, such pluripotent EPSC could only be produced from mice. Now that the biochemical signaling pathways have been determined more precisely, it is also possible to obtain EPSC from humans and pigs and then multiply them under established cell culture conditions.

Targeted production of developmental states

"The reprogramming of the cells to the original stage of a fertilized egg now offers the possibility of producing cell cultures with embryonic properties without actually having to use embryos for research purposes," explains the scientist. The research team has succeeded in biochemically inhibiting certain developmental pathways of embryonic stem cells and thereby elucidating the underlying molecular mechanisms. Using such embryonic models, it is possible to specifically establish desired developmental states, investigate disease progressions or investigate developmental disorders.

New possibilities for xenotransplantation?

Niemann believes that pig cells in particular offer ideal conditions for this. "The pig is an increasingly important model for biomedical research," he emphasizes. In addition, pig cells are easier to genetically modify because the protocols are well established. "In humans, for example, we have to consider tissue incompatibilities," explains Professor Niemann. "It may be possible to produce universally available and compatible tissue from pig cells that can be stored in a cell bank. Xenotransplantation, the replacement of solid organs from pig organs, also opens up new possibilities.

Research teams worldwide show interest

Until then, however, the results will have to be confirmed by other research groups. "We are making our work available to the scientific community so that it can be reviewed to prove that the data is solid." Niemann and colleagues cannot complain about a lack of interest. "We are currently being overwhelmed with inquiries," he says. Cells would have to be constantly packed and shipped worldwide so that others would be able to reproduce the experiments in their own laboratories. Meanwhile, Niemann is already working on his next research proposal. He estimates that the first tissue banks based on the EPSC procedure could be established in three to five years.

Establishment of porcine and human expanded potential stem cells.
Xuefei Gao; Monika Nowak-Imialek et al.
Nature Cell Biology volume 21, pages 687-699 (2019).
DOI: 10,1038/s41556-019-0333-2