Mutant TDP-43 drives impairments in axonal transport and glycolysis in a mouse stem-cell-derived motor neuron model of amyotrophic lateral sclerosis (ALS).

TDP-43 dysfunction is thought to be central to ALS pathogenesis. Studying mutations in the gene which encodes TDP-43, TARDBP, provides a valuable opportunity to gain insight into how TDP-43 dysfunction alters cellular homoeostasis. Our group has previously developed a TDP-43(M337V) mouse embryonic stem cell-derived motor neuron (mESC-MN) model, which expresses a single copy of the human TARDBP gene expressing the pathogenic M337V mutation at low levels. Here, we perform extensive phenotypic characterisation of this model, and show that TDP-43(M337V) leads to reduced MN viability, impaired axonal transport and reduced basal glycolysis compared to TDP-43(WT) controls. Altered neuronal viability and function occurs in the absence of TDP-43 mislocalisation or aggregation, suggesting 'proteinopathy' is downstream of these ALS-relevant phenotypes. These findings provide further support for a link between TDP-43 dyshomeostasis, cellular bioenergetics and axonal transport and suggest these pathways warrant further investigation as targets for therapeutic intervention.