Human iPSC-derived motor neurons with TDP-43 nuclear loss present early ALS pathological phenotypes

Abstract Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder characterized by progressive loss of motor neurons and presents a critical need for effective treatments. To investigate the impact of TAR DNA-binding protein 43 (TDP-43) nuclear depletion in ALS, we established and characterized a human-induced pluripotent stem cell-derived motor neuron model carrying a mutation that disrupts TDP-43 nuclear localization. The model successfully recapitulates functional deficits observed in ALS patients, including impaired neurite outgrowth, reduced axonal regeneration, and neuronal hyperexcitability. Proteomic and metabolomic profiling revealed early mechanisms underlying ALS neuronal pathophysiology, involving altered oxidative stress and neurotransmitter release. TDP-43 nuclear depletion led to mis-splicing STMN2 and KCNQ2 , defects characteristic of TDP-43-associated disease. Notably, a splice-switching antisense oligonucleotide successfully restored normal STMN2 splicing and function, demonstrating that directly correcting splicing defects can rescue motor neurons. This work provides a comprehensive understanding of TDP-43 nuclear depletion in the context of ALS pathogenesis and offers potential targets for RNA-targeted therapeutic intervention, pointing towards the development of precision medicine approaches and early diagnostic markers for ALS.