The use of stem cells for patient stratification approaches in motor neurone disease

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease resulting in the death of the upper and lower motor neurons. Therapeutic approaches towards ALS have always proven difficult due to the impressive genetic and phenotypic heterogeneity of the disease. By using patient-derived stem cells, we ran a drug screening to test the neuroprotective effect of three different anti-oxidant drugs. This study revealed that none of the three drugs was neuroprotective in all patient cultures, instead, we identified specific drug responders and non-responders, indicating that neuroprotection can be achieved with different drugs in different patients. Gene expression profiling of patients cells before and after drug treatment identified a specific gene signature able to discriminate patient responders. The main limitation of this approach is the feasibility of reprogramming skin fibroblasts into stem cells to assess the neuroprotective effect of specific drugs on patient-derived neurons. This approach would not be feasible in a real-life clinical setting; hence we aim to determine whether the responder gene signature can be identified in peripheral blood mononuclear cell (PBMC).
For this project we will focus specifically on one neuroprotective drug, namely M102 that is due to enter clinical trial in 2023 (Phase I trial funded by the MRC).

Objectives: 1. Test M102 on patient-derived neurons and identify patient responders and non-responders; 2. Perform RNA-Seq and corroborate the RNA signature biomarker of responders vs non-responders based on the co-culture results; 3: Determine the presence of a peripheral transcriptional signature that identifies responders in PBMCs isolated from the same donors

Novelty: Patient stratification approaches for neurodegenerative diseases are not established, although greatly needed. This study is novel in its approach, as it combines a novel methodology for cell reprogramming, which models more reliably patient phenotypes, transcriptomics and patient biosamples such as PBMCs.

Timeliness: With a clinical trial due to start in 2023, understanding the real potential of patient stratification through the analysis of transcriptomics of peripheral biosamples is of primary importance, as it will support a future platform for patient stratification.

Experimental Approach: We will 1. test M102 in 20 in vitro ALS patient-derived neuron lines to identify patient responders and non-responders; 2. Perform RNA-Seq on the same 20 patient cell lines before and after drug treatment to corroborate the previously identified RNA signature biomarker of responders vs non-responders based on the co-culture results; 3. Perform RNA-Seq on the PBMCs of the same 20 drug naïve donors to determine the presence of a peripheral transcriptional signature that identifies responders and ideally overlaps, at least in part, with the signature identified in vitro in point 2.