MODELING TDP43 PROTEINOPATHY IN ALS USING PATIENT-DERIVED CORTICO-SPINAL ORGANOIDS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive dysfunction and loss of cortical and spinal motor neurons. Despite genetic heterogeneity, a number of familial cases is driven by TARDBP mutations. When mutated, TDP43 - which physiologically shuttles from the nucleus to the cytoplasm - becomes hyperphosphorylated and accumulates into insoluble cytoplasmatic aggregates.
The lack of reliable models that accurately recapitulate ALS onset and progression remain a significant barrier to developing effective medical treatments. To overcome this limitation, we utilize a 3D modeling approach by deriving cortical and spinal organoids from patient-iPSC lines carrying heterozygous point mutations in the TARDBP C-terminal domain, alongside their isogenic control lines. Temporal analysis over a 90-day differentiation period revealed increased nuclear-to-cytoplasmic TDP43 mislocalization in mutant organoids as early as DIV (day in vitro) 30, compared to isogenic controls. Furthermore, we detected significant pTDP43 inclusions in both the cytoplasm and the nucleus, providing evidence of protein aggregation during early and late developmental stages.
These results confirm that our 3D model effectively captures the early-stage pathological behavior and protein dynamics that characterize TDP43 proteinopathy. Consequently, we aim to employ cortical and spinal organoids to recapitulate the cortico-spinal tract within an in vitro device, exploring the region-specific vulnerability of our ALS patient lines. The complete validation of these models provides a robust in vitro platform to investigate ALS traits across both the brain and the spinal cord.