Abstract
Amyotrophic Lateral Sclerosis (ALS) is a progressively fatal neurodegenerative disease that damages nerve cells in the central nervous system (CNS), but its effects are manifested in the peripheral nervous system (PNS) due to the loss of motor neuron function resulting in muscle weakness and atrophy. Although ~85-90% of ALS cases are sporadic, mutations in over 40 genes have been identified that contribute to the development of ALS (1).
There is no cure for ALS and approved treatments are primarily aimed at addressing symptoms. Lack of standardized, easy-to-use, and readily accessible human cell models has been a hurdle in early-stage ALS drug discovery. Human induced pluripotent stem cell (iPSC)-derived disease models, offer the promise of building better in-vitro models for increased translational relevance.
Hyperexcitability is a trait in ALS neuronal pathology contributing to the degeneration of motor neurons and disease progression. As such, should be an essential attribute in a disease model.
Here, we have successfully characterized axoCells human iPSC-derived motor neurons from six different donor lines including two unaffected donors, one C9orf72 carrying donor (the sibling to the C9orf72 ALS donor), and three donors each carrying significant genotypes associated with ALS; SOD1, C9orf72 and TDP43 for ALS drug discovery.
Using functional screening, the cells were shown to demonstrate a disease relevant phenotype when compared to the control. Through Brightfield imaging and Immunocytochemistry (ICC), the expected morphology and expression of neuronal marker TUJ1 (Neuron-specific class III beta-tubulin) was observed.
Spontaneous Neuronal activity (SNA) and Multi-electrode array (MEA) analysis displayed overall firing rates, synchronization of firing, length of bursts and amplitude of bursts consistent with the cells’ phenotype. Specifically, the ALS donor cells displayed a reproducible loss of synchronous firing and different degrees of hyperexcitability.
Multiple manufacturing runs showed batch-to-batch functional consistency with these results. Such successful characterization of these human iPSC-derived cells which display attributes in line with ALS clinical pathology, confirms their suitability to function as a disease model for ALS drug discovery.
