An interdisciplinary approach to unravel mechanistic understanding of Frontotemporal lobar degeneration

Dementia causes enormous personal hardship and costs the UK ~£23 billion every year. The second most common form is Frontotemporal lobar degeneration (FTLD). About 40% of FTLD cases have genetic causes, with >8% involving abnormal intronic GGGGCC hexanucleotide repeat expansions in the C9orf72 gene which can additionally cause motor neuron disease (OMIM #105550). These pathological expansions are actively transcribed and, via bidirectional repeat-associated non-ATG (RAN) translation, generate 5 different aggregate-forming GA, GR, PR, GP and AP dipeptide repeat proteins (DPRs).This project will gain new understanding of this type of FTLD by unravelling neurodegenerative pathomechanisms of DRPs through using interdisciplinary approaches. We will focus on the hypothesis that toxicity is caused by DRP structure, comparable to amyloid plaques in Alzheimer's disease. The project will capitalise on the complementary expertises of the three supervisors, and a readily available, unique set of 4 GFP-tagged constructs with high, pathologically relevant repeat numbers. The detailed aims and outcomes are:

To generate purified DRPs and perform biochemical and biophysical analyses, in order to understand the reasons for their toxicity and identify useful therapeutic strategies which will benefit patients and their families.
To generate transgenic Drosophila fly stocks to obtain primary neurons expressing the four DRPs. We will use powerful fly genetics and well established cell biological approaches to identify the neuronal death pathway and of the DRP-induced pathomechanisms upstream.
There is substantial proof-of-principle for the use and translational potential of Drosophila To validate identified DRP pathomechanisms in mammalian contexts, we will carry out complementary experiments using well established DRP models in SH-SY5Y cells and inducible neuronal cell lines.
This project is highly interdisciplinary, with the analysis of the dipeptide repeat proteins spanning systems from in vitro solvents to human and fly cell lines. The student will receive a broad training in characterisation of polypeptide structure and aggregation, cell culture, fly and human genetics, and cell biology, all in the context of genetic disease and neurodegeneration.