Homozygous ALS-linked mutations in TARDBP/TDP-43 lead to hypoactivity and synaptic abnormalities in human iPSC-derived motor neurons
Sarah Lépine,
Angela Nauleau-Javaudin,
Eric Deneault,
Carol X.-Q. Chen,
Narges Abdian,
Anna Krystina Franco-Flores,
Ghazal Haghi,
María José Castellanos-Montiel,
Gilles Maussion,
Mathilde Chaineau,
Thomas Martin Durcan
Affiliations
Sarah Lépine
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada; Faculty of Medicine and Health Sciences, McGill University, Montreal, QC H3G 2M1, Canada
Angela Nauleau-Javaudin
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada; Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
Eric Deneault
Centre for Oncology, Radiopharmaceuticals and Research; Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON K1A 0K9, Canada
Carol X.-Q. Chen
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
Narges Abdian
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
Anna Krystina Franco-Flores
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
Ghazal Haghi
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
María José Castellanos-Montiel
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
Gilles Maussion
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
Mathilde Chaineau
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada; Corresponding author
Thomas Martin Durcan
Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada; Corresponding author
Summary: Cytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43 is a pathological hallmark of the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS). Furthermore, while mutations in TARDBP (encoding TDP-43) have been associated with ALS, the pathogenic consequences of these mutations remain poorly understood. Using CRISPR-Cas9, we engineered two homozygous knock-in induced pluripotent stem cell lines carrying mutations in TARDBP encoding TDP-43A382T and TDP-43G348C, two common yet understudied ALS TDP-43 variants. Motor neurons (MNs) differentiated from knock-in iPSCs had normal viability and displayed no significant changes in TDP-43 subcellular localization, phosphorylation, solubility, or aggregation compared with isogenic control MNs. However, our results highlight synaptic impairments in both TDP-43A382T and TDP-43G348C MN cultures, as reflected in synapse abnormalities and alterations in spontaneous neuronal activity. Collectively, our findings suggest that MN dysfunction may precede the occurrence of TDP-43 pathology and neurodegeneration in ALS and further implicate synaptic and excitability defects in the pathobiology of this disease.
