During blood cell development transcription factors direct multipotent haemopoietic stem cells (HSC) to make all the different kinds of blood cells in the right amounts. When blood cell development goes wrong, making too few, too many or the wrong cells, it causes disease. This makes HSCs a cell type of central interest for regenerative medicine and gene therapy. How transcription factors direct and maintain a normal population of HSCs and balanced output of the different mature blood cells is fundamentally important. We recently discovered the transcription factor Zbtb11 is essential for blood and stem cell development. Our group investigates the cell biology and molecular mechanisms of how and why blood development fails in the absence of Zbtb11 using our unique zebrafish models of Zbtb11 deficiency. This understanding will provide important foundational knowledge for effectively manipulating blood cell outputs in the clinic to treat disease.
Research areas
Zbtb11-mediated molecular mechanisms impacting haemopoietic stem cell function
The blood system is constantly being renewed and increased production of particular blood cell types is required to respond to different diseases or injury. This occurs via the haemopoietic stem cell (HSC) under instruction of molecular and cellular pathways. Transcription factors bind DNA to control how much of a specific gene will be made into protein. Understanding how transcription factors work to maintain a normal population of HSCs and a balanced output of the mix of different mature blood cell populations is central to our understanding of how to manipulate blood cell outputs in the clinic to treat disease.
Our Zbtb11-deficient zebrafish mutant has shown that Zbtb11 is required for HSC maintenance and/or survival. Using Next Generation Sequencing technologies, in vivo genetic and pharmacological manipulation of candidate pathways and biochemical assays this project aims to understand the downstream target genetic and biochemical pathways that are regulated by Zbtb11 and result in loss of HSCs in both zebrafish and mammals.
Splicing dysregulation and haemopoietic disease
Splicing of pre-mRNA occurs in all eukaryotic cells to ensure correct gene expression. Although it is a ubiquitous process it arises differently in different cell types to achieve diverse biological outcomes specific to a particular cell type. This is highlighted by the phenotypes generated by splicing factor mutations in human diseases. These are remarkably specific, often leading to degenerative disease and/or cancer in a few specific tissues, even when the mutations are congenital. Myelodysplastic syndromes (MDS) are a common, heterogeneous group of haemopoietic stem cell disorders characterised by peripheral cytopenias and a predisposition to transform into secondary acute myeloid leukaemia. Recurrent splicing factor mutations are prevalent in MDS, implicating the splicing machinery in MDS pathogenesis and prognostic significance. We aim to better understand the paradox of ubiquity versus tissue specificity in splicing using granulopoiesis as a paradigmatic biological and haematological process susceptible to splicing regulation in both health and disease.
Zbtb11 deficiency and in vivo tracking of HSCs
We have shown that in a zebrafish model of Zbtb11 deficiency HSCs disappear not long after they are first made. This project aims to determine precisely when HSCs are lost and why they disappear. Live imaging of optically transparent zebrafish larvae by confocal microscopy allows fluorescently labelled HSCs to be tracked from when they first appear to when they disappear. This enables us to directly observe and quantify crucial aspects of early HSC development as they happen in real time.
