HUMAN CORTICAL AND SPINAL CORD ORGANOIDS REVEAL CELL-TYPE–SPECIFIC CONSEQUENCES OF TDP-43 I383V MUTATION

Mutations in TARDBP, encoding the RNA-binding protein TDP-43, are causally linked to neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal dementia. Despite this, how disease-associated TDP-43 mutations affect human neural development and cell-type-specific transcriptional programs remains incompletely understood.
Here, we model TDP-43-associated neurodegeneration using human induced pluripotent stem cell-derived cortical and spinal cord organoids carrying the TARDBP I383V mutation and their isogenic controls (I383I). Organoids were cultured over extended developmental timeframes and analyzed using single-cell RNA sequencing, RT-qPCR, and immunofluorescence to assess transcriptional and cellular changes.
Across both cortical and spinal cord organoids, the TDP-43 I383V mutation induces reproducible transcriptional alterations that evolve over time. These changes preferentially affect neuronal populations and include dysregulation of gene programs related to RNA metabolism, neuronal identity, and cellular stress responses. Immunofluorescence analyses support cell-type-specific effects of the mutation, while RT-qPCR validates selected transcriptional changes. Notably, cortical and spinal cord organoids display partially distinct transcriptional signatures, suggesting region-specific consequences of TDP-43 dysfunction. Together, these findings establish human cortical and spinal cord organoids as complementary platforms to study TDP-43-associated neurodegeneration and reveal early, cell-type-specific effects of the TARDBP I383V mutation. This work provides a human-relevant framework to investigate mechanisms underlying selective neuronal vulnerability in TDP-43 proteinopathies.