New Type of Stem Cell Line Produced: Offers Expanded Potential for Research and Treatments
Scientists have created Expanded Potential Stem Cells (EPSCs) that, for the first time, can produce all three types of blastocyst stem cells – embryo, placenta and yolk sac.
Researchers at the Wellcome Trust Sanger Institute and their collaborators have created Expanded Potential Stem Cells (EPSCs) in mice, for the first time, that have a greater potential for development than current stem cell lines. These stem cells have the features of the very first cells in the developing embryo, and can develop into any type of cell.
Published in Nature the methods used could also help produce similar stem cell lines from human and other mammalian species, including those such as pigs or cows where embryonic stem cell lines are still not available.
The researchers also believe that their study could have implications for human regenerative medicine and for understanding miscarriage and developmental disorders.
“EPSCs [expanded potential stem cells] provide a platform to study early embryo cells in detail at the molecular level to understand development, not only in mouse, but ultimately in future in humans. This new method of producing stem cells could be enormously helpful for studying development, more efficiently generating functional human cells, and researching treatments for pregnancy problems such as pre-eclampsia and miscarriages,” Dr Jian Yang, a first author on the paper from the Wellcome Trust Sanger Institute said.
Stem cells have the ability to develop into other cell types, and existing stem cell lines are already extremely useful for research into development, disease and treatments. However, the two currently available types of stem cell lines – Embryonic Stem cells (ES) and induced Pluripotent Stem cells (iPS) – have certain limitations. It is not currently possible for them to form every type of cell since they are already excluded from developing certain cell lineages.
To discover new stem cells for use in research and regenerative medicine, the researchers created a way of culturing cells from the earliest stage of development, when the fertilised egg has only divided into 4 or 8 cells that are still considered to retain some totipotency – the ability to produce all cell types. Their hypothesis was that these cells should be less programmed than ES cells, which are taken from the around-100-cell stage of development – called a blastocyst. They grew these early cells in a special growth condition that inhibited key development signals and pathways.
“This is a fantastic achievement, by working with the very earliest cells, this study has created stem cell lines that can form both embryonic and all the extra-embryonic cells. The methods and insights from this study in mice could be used to help establish cultures of similar stem cells from other mammalian species, including those where no ES [embryonic stem] or iPS [induced pluripotent stem] cell lines are available yet. The research also has great implications for human regenerative medicine as stem cells with improved development potential open up new opportunities. Further research in this area is vital, so that we can properly explore the potential of these cells,” Professor Hiro Nakauchi, a co-author on the paper from Stanford University said.
The scientists discovered that their new cultured cells kept the desired development characteristics of the earliest cells and named them Expanded Potential Stem Cells (EPSCs). Importantly, they were also able to reprogramme mouse ES cells and iPS cells in the new condition and create EPSCs from these cells, turning back the development clock to the very earliest cell type.
Materials provided by the Wellcome Trust Sanger Institute. Note: Content may be edited for style and length.