Transcriptional control of haematopoietic specification and differentiation

Lead Research Organisation: University of Oxford

Abstract

Our interests focus on the mechanisms that underlie blood formation and differentiation into mature blood cells (such as those fighting infection, involved in coagulation or in oxygen transport). Many inherited and acquired diseases are associated with anaemia and leukaemia in which production of certain types of blood cells is disrupted. Understanding these disorders depends on knowing how blood normally forms in the bone marrow and throughout development. Recently, there has been considerable accumulation of knowledge about the factors that direct formation of the blood. One such factor (called SCL, Stem Cell Leukaemia) plays several critical roles in this process. We plan to understand how this factor controls the formation of blood at a molecular level. Our main experimental model makes use of mouse embryonic stem (mES) cells that can reproduce the early steps of embryonic development in vitro (in a culture dish). We aim at understanding how a blood-specific protein complex forms, how it regulates the coordinated expression of the critical players involved in this pathway and how, when it is deregulated, it may lead to leukaemia and anaemia.

Technical Summary

Understanding how stem cells are specified during embryonic development and how lineages differentiate to produce mature and specialised cells are central questions in biology and are of crucial interest to elucidate pathways involved in diseases. The main aim of this programme is to characterise some of the molecular mechanisms engaged by key regulators of blood development (such as SCL/Tal1), with a particular focus on the early stages of mesoderm patterning and haematopoietic specification. Functional identification of protein complexes and their nuclear targets combined with molecular characterisation of their mechanisms of action and structural biology approaches will give insights into genetic interactions and transcriptional networks critical in decision pathways. Using in vitro differentiation of mouse ES cells, mouse haematopoiesis and Xenopus embryos as experimental models, we will start building networks of genetic interactions at the heart of haematopoietic development. These approaches are instrumental for our understanding of how a haematopoietic stem cell-specific protein complex might form and how, when this process is deregulated, this leads to leukaemia. Moreover, this might help characterise the pathways leading to definitive haematopoiesis and HSCs from hES and iPS cells that remain poorly characterised. This is important if one wants to be able to produce HSCs in vitro for regenerative medicine purposes.
 
Title Development of protocols supporting mouse and human ES cell differentiation towards the hematopoietic stem cell lineage 
Description We are currently developing protocols supporting the stepwise differentiation of mouse and human ES cells towards the hematopoietic stem cell lineage. We now have protocols that sustain the initial steps of mouse and human ES cell differentiation. These will be extended in the coming months to support the later stages of this differentiation. 
Type Of Material Technology assay or reagent 
Year Produced 2019 
Provided To Others? No  
Impact No impact yet 
 
Title Scl:mCherry ES cell line 
Description Insertion of the mCherry reporter gene into the Scl locus in mouse ES cells 
Type Of Material Cell line 
Year Produced 2018 
Provided To Others? Yes  
Impact We can now follow the cellular fate of Scl-null cells. This has allowed to report a cell fate change from blood to cardiac/paraxial lineages in absence of this transcriptional regulator. This is a critical finding for our mechanistic understanding of lineage specification. 
URL https://www.nature.com/articles/s41467-018-07787-6
 
Title Whole genome sequencing databases (Flk1+ cells) 
Description RNA-seq, ChIP-seq, ATAC-seq databases from blood-fated mesodermal cells 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact This has provided new insight into the molecular mechanisms underlying lineage specification and highlighted the functional importance of repression mechanisms. More specifically, how a tissue-specific regulator activates a lineage-specific gene expression programme and represses alternative fates in the same cell. This is an important concept likely to apply to other cellular systems. 
URL https://www.nature.com/articles/s41467-018-07787-6
 
Description Cryo-EM 
Organisation University of Oxford
Department Oxford Hub
Country United Kingdom 
Sector Academic/University 
PI Contribution Intellectual and experimental: choice of protein complex to analyse structurally; performing experiments.
Collaborator Contribution Experimental: advice and help to produce and analyse the structure of multi-protein complexes by cryo-EM
Impact In progress
Start Year 2019
 
Description HSC production from mouse and human ES cells 
Organisation Medical Research Council (MRC)
Department MRC Molecular Haematology Unit
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise in mouse and human ES cell cultures and differentiation
Collaborator Contribution Expertise in haematopoiesis during embryonic development to help design protocols aiming at reproducing blood development in vitro.
Impact We are currently characterising ES cell-derived haematopoiesis in order to be in a better position to produce blood stem cells in vitro. If successful, we will be closer to making blood stem cells from patient's own cells. This is a long-term project.
Start Year 2014
 
Description Mouse and human ES cell differentiation cultures with NIH 
Organisation National Institutes of Health (NIH)
Country United States 
Sector Public 
PI Contribution Expertise in mouse ES cells and developmental haematopoiesis
Collaborator Contribution Expertise in human ES cell differentiation cultures that complement our mouse ES cell expertise.
Impact Mouse ES cell differentiation protocol that recapitulates some of the milestones occurring during embryonic development of blood stem cells.
Start Year 2014
 
Description Normal human hematopoiesis 
Organisation University of Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution Intellectual
Collaborator Contribution Intellectual and experimental
Impact Better understanding of the hematopoietic hierarchy in humans.
Start Year 2015
 
Description Role of Gata1s in fetal megakaryopoiesis 
Organisation University of Oxford
Department Radcliffe Department of Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution Co-supervision of a post-doctoral scientist. Bringing expertise in Cellular and Molecular Biology.
Collaborator Contribution Expertise in megakaryopoiesis and function of GATA1 in hematopoiesis
Impact No outputs yet.
Start Year 2016
 
Description Spatial genomic analysis 
Organisation University of Helsinki
Country Finland 
Sector Academic/University 
PI Contribution Experimental
Collaborator Contribution Intellectual and analytical
Impact Analysis of complex imaging data generated by quantitative, in situ single molecule RNA FISH.
Start Year 2019
 
Description Meet the expert session on career development (ISEH 2018) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I had a discussion with 3 groups of 10 students and post-docs about careers in academia versus industry and issues related to women in science. These workshops are intended to provide role models to young scientists and to engage them into a reflection about their career.
Year(s) Of Engagement Activity 2018
 
Description School visit (MCS) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact The talk inspired discussions and reflection on biomedical/science-related careers.

Following the talk, I had request from pupils wanting to do work experience in my lab. We hosted 4 of those in the summer.
Year(s) Of Engagement Activity 2015,2016,2017,2018,2019
 
Description Science Bazaar 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Stand in Oxford Brookes University with activities about DNA folding targeting children aged 5-14. This sparked questions and discussions with the children and their parents.
Year(s) Of Engagement Activity 2020
 
Description Science Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public Engagement stand on cancer immunotherapy in a shopping centre. 700 people attended and engaged into discussion and children participated in hands-on activities.
Year(s) Of Engagement Activity 2019
 
Description Video DG 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Short video of PhD student explaining what his thesis project is about. Organised by University of Oxford Graduate Study to inspire prospective students.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=5jSJ4sYYySM
 
Description Work experience in the lab 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact 2 pupils from disadvantaged background spent 2 weeks in our laboratory to gain experience in biomedical research. They participated in various scientific experiments, discussions, lectures and workshops.
Year(s) Of Engagement Activity 2019