Breakthrough in deriving early embryonic stem cells

19 June 2019

An international team of scientists has developed a new approach to derive expanded potential stem cells (EPSCs) from both pig and human cells.

These stem cells have the features of the very first cells in the developing embryo, and can develop into any type of cell. They offer potential for studying human development and regenerative medicine.

The study published in Nature Cell Biology was led and conducted by Professor Pengtao Liu’s laboratory at the University of Hong Kong (HKU), in collaboration with Professor William Yeung (Croucher Fellowship 1985), of the Department of Obstetrics and Gynaecology at HKU, together with scientists from the Wellcome Sanger Institute in Cambridge, UK, and the Friedrich-Loeffler-Institut, Germany.

Domestic pigs have great potential for biomedical research due to their genetic and anatomical similarities to humans, including comparable organ sizes. Being able to genetically modify pig stem cells is also expected to be beneficial for animal health and food production.

Scientists have attempted to derive porcine embryonic stem cells for decades without much success, until the team used its expanded potential stem cell technology to derive and characterise stem cells from porcine preimplantation embryos. They have also established similar human stem cells – a significant advance in stem cell research.

EPSCs have higher developmental potency than conventional embryonic or induced pluripotent (immature) stem cells. Conventional stem cells are usually established from pre-implantation embryos made up of dozens of cells called blastocysts. With the new technology, scientists can derive stem cells from pre-implantation embryos before the blastocyst stage. At that early stage, cells are like a blank sheet of paper – less differentiated and with potential to develop into more kinds of cells.

The researchers explained: “They (EPSCs) have the potential to produce all embryonic and extra-embryonic cell lines – including those in the placenta and yolk sac, turning back the development clock to the very earliest cell type. These cells will enable researchers to study early embryonic development, miscarriage and developmental disorders.”

The team has so far established mouse, pig, and human EPSCs. These new stem cells across species are molecularly similar and amenable to multiple rounds of genome editing. Besides their capacity to produce all types of cells found in our body and being useful for studying human disease and regenerative medicine, human EPSCs can create large numbers of placenta cells, called trophoblasts, which would offer new opportunities to investigate pregnancy complications such as pre-eclampsia and miscarriages.

The study was led and conducted by Professor Pengtao Liu (right) in collaboration with Professor William Yeung (middle)

Yeung said: “EPSCs have provided a new tool of studying the development of early human embryos, especially the regulation of placental development. Researchers can now use the unique ability of EPSCs in forming placental cells to understand the etiology of pregnancy complications due to early placental dysfunction.”

Building on this work, the researchers are continuing to push the EPSC technology, collaborating with other research groups. Yeung and his colleagues are excited that these new stem cells are expected to have broad applications in basic and translational research in the near future.

Professor William Yeung Shu Biu is a professor in the Department of Obstetrics and Gynaecology at the University of Hong Kong. His research focus on interaction between sperm or embryo with the female reproductive tract; function of glycodelins; fertilisation, microRNAs and reproduction, and endometrial stem cells. Professor Yeung received the Croucher Fellowship in 1985 to work with Professor B T Pickering on neuropeptide hormones at Department of Anatomy, University of Bristol.


To view Professor Yeung’s Croucher profile, please click here