Investigating modifier transcripts in mouse models of motor neuron disease

This project will focus on a variety of disorders that are summarised under the term "motor neuron disease" and whose primary pathological target are motor neurons. Even though motor neurons are the primary target of these diseases, not all motor neurons are equally vulnerable to pathology. Some motor neurons are affected and lost very early in the course of the disease, while others are much less affected and stay comparatively intact until late stages of the disease. This can be shown in both patients and in animal models, including mouse models of these diseases. This knowledge creates a valuable basis for this project, opening the possibility for the investigation of factors that regulate motor neuron vulnerability.

The goal of this project is to identify transcripts that can alter motor neuron vulnerability and use this newly gained knowledge to contribute to the development of neuroprotective drugs. The first aim is to identify potential commonalities between differentially vulnerable motor neurons. In order to achieve this, bioinformatics is going to be used to compare independent screens on differentially vulnerable motor neurons. Large data sets will be analysed, pathway analysis will be performed and functional clustering will be used to generate a list of high priority transcripts, based on similar methods used in Kline et al. (2017). Furthermore, a range of muscles from an intermediate SMA-like mouse model will be analysed for NMJ pathology to investigate their differential vulnerability, in comparison to a more severe mouse models of the disease and how this relates to identified transcripts of interest.

The second aim is to investigate potential protective or degenerative qualities and mechanisms of action through knock-down or overexpression of modifier transcripts in human stem cell-derived motor neurons (iPSCs).

The third aim is to investigate any protective effects of modifier transcripts in a mouse model of motor neuron disease. Transcripts and pathways identified in the aims described above will be manipulated using a combination of pharmacological approaches and viral gene therapy. Pathological analysis of the neuromuscular system will be performed, which will include sectioning and staining of spinal cords to perform motor neuron counts, and dissecting and staining muscles to perform analysis of neuromuscular junctions.

Independent studies in the laboratories of both supervisors of this project already observed differentially vulnerable motor neurons and identified transcripts which display an altered expression level between vulnerable and resistant motor neurons (Hedlund et al., 2010; Murray et al., 2015). They therefore predict that these transcripts could be effective modifiers of disease. This project will further investigate their potential neuroprotective or neurodegenerative qualities and mechanism of action.