Neuromesodermal progenitor (NMPs) give rise to neural and mesodermal tissues during axis elongation. In their study, Fay Cooper, Anestis Tsakiridis and colleagues reveal the role of Notch signalling in NMP differentiation and its role in Hox gene expression. To learn more about their work, we spoke to first and co-corresponding author, Fay Cooper, and to co-corresponding author Anestis Tsakiridis, Group Leader at the University of Sheffield, UK.
Fay Cooper (left) and Anestis Tsakiridis (right)
Anestis, can you give us your scientific biography and the questions your lab is trying to answer?
AT: In terms of scientific training, I am an Edinburgh man: after completing my first degree in Biochemistry at the University of Edinburgh, I did a PhD in Lesley Forrester's group in the Medical School of the same university, working on the development of novel gene trap vectors, aiming to identify and mutate haematopoiesis regulators in mouse embryonic stem cells (ESCs). I then moved to Josh Brickman's lab in the Institute for Stem Cell Research (ISCR; formerly the Centre for Genome Research) in Edinburgh to continue, as a postdoc, my work on building tools for functional genomics screens in mouse ESCs. I did a second postdoc with Val Wilson in the MRC Centre for Regenerative Medicine (ISCR's next incarnation) looking at the links between pluripotency reactivation and teratocarcinoma formation, as well as developing mouse and human in vitro models for studying the progenitors that drive embryonic axis elongation. In 2016, I left Edinburgh to start, as a Vice Chancellor's Fellow, my own lab in the Centre for Stem Cell Biology in Sheffield, an excellent place for human ESC research that was led by Peter Andrews – I have been based there since then.
As a group, we aim to understand how human ESCs adopt distinct anteroposterior (A-P) axial identities as they transit from pluripotency to lineage commitment, with a particular focus on the specification of spinal cord precursors and neural crest. More recently, we have been increasingly focusing on the development of human ESC-based platforms for treating and studying Hirschsprung disease and neuroblastoma – two very serious neural crest-associated conditions affecting young children.
Tell us about the background of the field that inspired your work
FC & AT: We have a long-standing interest in how signalling pathways and transcriptional factors cooperate to guide cell fate decisions in neuromesodermal progenitors (NMPs) the bipotent cell population that generates both paraxial mesoderm and spinal cord neurectoderm during amniote embryonic axis elongation. The best-studied signalling pathways controlling NMPs are Wnt and Fgf. However, both embryonic and human ESC-derived NMPs are also marked by high expression of various components of the Notch signalling pathway, another key developmental signalling pathway. Moreover, disruption of Notch signalling in vivo has been shown to severely disrupt posterior patterning and axis elongation. Although the role of Notch in somitogenesis and spinal cord formation is well studied, its earlier involvement in NMP induction and differentiation has been unclear. This prompted us to study the effects of its inhibition using our established human ESC differentiation protocols toward human NMPs and their derivatives. We were fortunate to collaborate with Kim Dale and her group from the University of Dundee, who examined the in vivo role of Notch inhibition in chick embryonic NMPs, nicely complementing our human ESC-based work.
Can you give us the key results of the paper in a paragraph?
FC & AT: A main hallmark of NMPs is the co-expression of pro-neural and pro-mesodermal transcription factors, such as Sox2 and T/brachyury (TBXT in humans). The antagonistic interaction between these lineage-specific transcription factors determines the balanced production of neural versus mesodermal cell types from NMPs. NMPs are also marked by the concomitant expression of Hox gene family members, which are activated in a sequential manner reflecting their 3′-to-5 ′ genomic order, a process that is thought to be linked to the assignment of an A-P axial identity in NMP derivatives. In our paper, we show that Notch signalling: (1) mediates the induction of pro-mesodermal and Hox genes in human ESC-derived NMPs via potential crosstalk with Fgf signalling; (2) controls the expression of some Hox genes in NMPs in a non-cell autonomous manner; and (3) biases chick embryonic NMPs towards a paraxial mesoderm at the expense of a ventral neural tube/floor plate fate. These data indicate that Notch contributes, together with Wnt and Fgf, to the primary signalling axis that orchestrates NMP cell fate decisions and positional identity acquisition.
Fay, when doing the research, did you have any particular result or eureka moment that has stuck with you?
FC: For me, this was seeing the in vivo experiments from the Dale lab. These experiments sound so technically tricky, but the results are beautiful and mirrored what we were seeing in our in vitro human model.
SOX2 (green), TBXT (magenta), HOXC9 (grey) and DAPI (blue) in human embryonic stem cell-derived neuromesodermal progenitors
And what about the flipside: any moments of frustration or despair?
FC: Working with human stem cells you often have moments of frustration! During the revisions, I was having a bit of trouble with our extracellular matrix for cell culture so it took us longer than expected to start some of our experiments, but we did it in the end!
Why did you choose to submit this paper to Development?
AT: As James Briscoe and Katherine Brown nicely pointed out in their early 2024 editorial, publishing is political and we like Development because of its commitment to the developmental biology community and not-for-profit stance. Many of my articles, both as a postdoc and a group leader, have been published there, and I have always had a great experience with editorial handling and a fair, rigorous reviewing process. We are also looking forward to having our next tree planted in The Forest of Biologists!
We like Development because of its commitment to the developmental biology community and not-for-profit stance
What is next for you after this paper?
FC: Currently, I'm exploring how Notch signalling influences cell fate decisions after NMP specification. I have also just started working on a new project where we will use an in vitro model of trunk neural crest differentiation to study neuroblastoma. In the next year, I also hope to apply for independent fellowships...so, I have a lot to do!
Where will this story take your lab next?
AT: As Fay mentioned, we are continuing our work on Notch signalling-based control of developmental cell fate decisions – some new exciting data are being generated right now so watch this space!
Finally, let's move outside the lab – what do you like to do in your spare time?
AT: In no particular order, I enjoy cinema, music, books, pubs, chess, walking in the Peak District, spending time with friends and family.
FC: I have a VERY active springer spaniel so I spend most of my time in the Peak District walking with him. I also enjoy wild swimming (in the warmer months) and I've recently started running again.
School of Biosciences and Neuroscience Institute, The University of Sheffield, Sheffield S10 2TN, UK.
E-mail: [email protected]; [email protected]
