Developing pluripotent stem cell models of inherited retinal diseases

Project description

Inherited retinal dystrophies are a leading cause of blindness and visual loss in the UK working age population. However, despite the widespread diagnostic use of next-generation sequencing, a molecular genetic diagnosis is unavailable for many patients world-wide. Understanding the genetic causes of these conditions enables accurate counselling of patients, improves knowledge of disease pathogenesis and catalyzes the development of novel treatments. To address the current limitations of genetics, this project will develop in vitro cellular modelling of inherited retinal disease in novel microfluidic devices, an approach that is currently under-studied and under-developed. This approach will hugely increase both throughput and the capacity to perform combinatorial assays because existing methods of retinal cell differentiation are costly, laborious and time-consuming.

Environment

We have an existing track-record in induced pluripotent stem cell (iPSC) characterization, differentiation into retinal cell types (retinal pigment epithelium and retinal organoids) and systematic characterization of normal and diseased cellular phenotypes [1]. We have also developed a range microfluidic devices [2], including for the rapid separation of mesenchymal stromal cells, with minimal manipulation, for autologous cell therapies [3].

Approach

The project will prototype initial PDMS (polydimethylsiloxane)-based “organ-on-a-chip” devices that enable wide-field microscopy in order to visualize cellular phenotypes. The iPSCs will be differentiated into retinal pigment epithelium following a standard protocol over 21 days [1]. The use of microfluidic devices will minimize culture volumes and cell manipulation, enabling higher throughput and potentially reducing the cost, labour and time that is required for assays of cellular phenotypes. Running several devices in parallel will enable the optimal design to be rapidly chosen for full-scale manufacture. In parallel, we will introduce mutations into normal control iPSCs using CRISPR-Cas9 gene-editing that will model RPE disease in patients. Once the basic design of the chip is optimized for RPE differentiation, we will manufacture multiplexed chips to enable matched sets of combinatorial assays to be performed in parallel (e.g. characterizing a range of cellular phenotypes using a panel of antibodies, reverse genetics screening with a panel of different CRISPR-Cas9 reagents to gene-edit different mutations, testing responses to a panel of drugs or small molecules). The incorporation of transparent indium tin oxide electrodes into the chip will enable transepithelial electrical resistance (TER) assays of cell monolayer integrity in mature RPE. In the longer term, we envisage culture of retinal organoids on chips, and their co-culture with RPE, will enable a more physiological tissue system to be developed. Furthermore, the manufacture of electrodes in the devices will enable us to assay physiological functions such as light-evoked responses.

Outcomes

The project develops methods for in vitro cellular modelling of inherited retinal disease in novel microfluidic devices. This is an approach that provides a more physiological model system for interrogating and understanding human genetic variation in health and disease. It provides unusually broad training research for an excellent graduate who is motivated and proactive in developing a novel area of multi-disciplinary biomedical research.

Techniques used in this project

Stem cell culture and differentiation, cellular function assays, confocal microscopy and live cell imaging, CRISPR-Cas9 gene editing (knock-out, knock-in and base editing), microfluidic chip design and manufacture.

References

1. Buskin A, Zhu L, Chichagova V, Basu B, Mozaffari-Jovin S, …33 others… Grellscheid S-N, Johnson CA, Lako M (2018). Disrupted alternative splicing for genes implicated in splicing and ciliogenesis causes PRPF31 retinitis pigmentosa. Nat Commun 9:4234.

2. Rimsa R, Smith AJ, Wälti C, Wood CD (2017). A planar surface acoustic wave micropump for closed-loop microfluidics. Appl Phys Lett 111:234102.

3. Smith AJ, O'Rorke RD, Kale A, Rimsa R, Tomlinson MJ, Kirkham J, Davies AG, Wälti C, Wood CD (2017). Rapid cell separation with minimal manipulation for autologous  cell therapies. Sci Rep 7:41872.

 

Entry requirements

This project is available immediately to both Home/EU rate applicants and International applicants who are have a sponsor or are able to self-fund their studies. You must be able to provide the appropriate level of fees based on their fee status plus laboratory consumables costs per year. This is in addition to the provision of personal living expenses.

You should hold a first degree equivalent to at least a UK upper second class honours degree in a relevant subject.

Candidate whose first language is not English must provide evidence that their English language is sufficient to meet the specific demands of their study, the Faculty minimum requirements are:

•      British Council IELTS - score of 6.5 overall, with no element less than 6.0

•      TOEFL iBT - overall score of 92 with the listening and reading element no less than 21, writing element no less than 22 and the speaking element no less than 23.

Applicants with sufficient funding must still undergo formal interview prior to acceptance in order to demonstrate scientific aptitude and English language capability.

How to apply

Applications can be made at any time. To apply for this project applicants should complete a Faculty Scholarship Application form and send this alongside a full academic CV, degree transcripts (or marks so far if still studying) and degree certificates to the Faculty Graduate School fmhgrad@leeds.ac.uk

We also require 2 academic references to support your application. Please ask your referees to send these references on your behalf, directly to fmhgrad@leeds.ac.uk

If you have already applied for other scholarships using the Faculty Scholarship Application form this academic session you do not need to complete this form again. Instead you should email fmhgrad@leeds.ac.uk to inform us you would like to be considered for this scholarship project.

Any queries regarding the application process should be directed to fmhgrad@leeds.ac.uk.

How to apply (email)

fmhgrad@leeds.ac.uk