SIG STEM CELLS

In vitro modelling for state-of-the-art Campus meeting in September

It is a pleasure to report that many of the upcoming ESHRE events will involve stem cells. First, our precongress course in Barcelona will focus on Stem cell therapies in clinical applications: Progress and challenges. The course will include several topics relating to the clinical applications of stem cells, such as clinical grade stem cell banking and HLA typing. We will also discuss recent clinical trials using endometrial stem cells and other stem cells in female and male infertility. Finally, we will deliberate on the possible future use of human pluripotent stem cells, with a focus on the treatment of two diseases, blindness and diabetes. Our aim in the course is to provide state-of-the-art insights into stem cell therapies in infertility and the tools required for future clinical trials.

It is also our pleasure to announce that the keynote lecture in the Annual Meeting will be given by the widely acclaimed Japanese group leader Katsuhiko Hayashi. His group was able to produce oocytes completely in vitro, starting from pluripotent stem cells and resulting in fertile pups. This method involved a fascinating 3-step in vitro culture system. I am sure that he will deliver a captivating discussion of this significant breakthrough in the field of stem cells.

Campus events
Our next event is a Campus course on In vitro modelling: from Embryo to Gametes, which will be held in Bilbao on 20-21 September 2018. We are extremely excited to invite several experts in areas including 3D modelling of the embryo, ovary and testis, artificial human blastocysts, embryo imaging methodologies, novel in vitro implantation strategies for studying endometrium and blastocyst interactions, and the epigenetics of human primordial germ cells. These are the most trending topics in the fields of early development and gametogenesis, currently providing a greater understating of previously uncharted processes. These investigations will certainly contribute to the ultimate goal of reproductive science and medicine, providing future treatments for overcoming infertility. This Campus event is already announced on the ESHRE Education pages, so please visit the ESHRE website and do not forget to register!

Nicolas Rivron, one of the invited speakers in our ESHRE Campus in Bilbao has just co-authored a remarkable manuscript in Nature ('Blastocyst-like structures generated solely from stem cells').(1) The authors managed to culture mouse trophoblast stem cells (mTSC) with mouse embryonic stem cells (mESC) in such a way that the mTSC arrange themselves as a hollow sphere surrounding a small mass of mESC, very reminiscent of a mouse 3.5-day blastocyst. These structures, named ‘blastoids’ were generated with a high efficiency and are in principle clones of the donor mESCs. While this ‘blastoid’ does not generate a viable mouse embryo after embryo transfer or even a recognizable epiblast structure, it was found to induce a decidualization response in the mouse uterus, as observed previously with the use of a plastic bead.
While Rivron’s blastoids do not develop in vitro towards gastrulation, the team of Zernicka-Goetz recently generated a 6-day (peri-implantation) embryo-like structure from mTSC and mESC, which was able to initiate gastrulation in vitro.(2) Nevertheless, both embryo-like structures share some comparable aspects. Although this new technology uses mouse cells, this may soon be translated to the human, especially now that the derivation of human TSC has been described. Future work may offer interesting research opportunities for unravelling the complex mechanisms underlying embryogenesis.

Looking ahead even further
Looking ahead to the Annual Meeting in Vienna in 2019, one of the keynote lectures will be focused on the celebrated gene editing technology CRISPR/Cas, a subject of great excitement in both the stem cell and reproduction fields. I would further add that our main session topic will focus on 3D reproductive organs, discussing the new biotechnological approaches of using stem cells to generate male and female organs.

Finally, we are planning to organise two new Campus events in 2019-2020. The first will be held in May 2019, together with the SIG Reproductive Genetics in Lisbon, entitled Gene editing tools for reproductive medicine: are we close? and will cover topics such as the CRISPR/Cas methodology, CRISPR tools, CRISPR/Cas in vivo, as well as its associated methodological limitations, including mosaicism in human embryos.

Our second Campus event will be organised with the SIG Embryology in 2020. Here, we will discuss a variety of topics that couple stem cells and development, such as trophectoderm stem cells, the artificial blastocyst, pluripotency factors, the concept of potency (pluripotency, totipotency…) and chromatin remodeling in development, amongst others. Both Campus events will be very relevant for the entire reproductive community, providing the latest updates in both stem cell research and exciting future applications of stem cells within the reproductive field.

Lastly, we are writing a review paper to celebrate the 20th anniversary of the first derivation of human embryonic stem cell lines. This anniversary offers an ideal opportunity to look back over the past two decades in this field, as well as to look forward to what the future may hold. We hope that this review, together with interviews of stem cell personalities such as Shinya Yamanaka, Alan Trounson, Outi Hovatta, Peter Andrews, Shoukhrat Mitalipov and Miodrag Stojkovic, will inspire young investigators to continue working on the fascinating topic of stem cells.

Cristina Eguizabel
Co-ordinator SIG Stem Cells

1. Rivron NC, Frias-Aldeguer J, Vrij EJ, et al. Blastocyst-like structures generated solely from stem cells. Nature 2018; 557: 106-111.
2. Harrison SE, Sozen B, Christodoulou N, et al. Assembly of embryonic and extraembryonic stem cells to mimic embryogenesis in vitro. Science 2017; 356: doi: 10.1126/science.aal1810.