Cell death detection in iPSC-derived cortical neurons as model of neurodegeneration

Induced pluripotent stem cells (iPSCs) represent an innovative tool to model neurodegenerative disorders, providing access to disease-relevant cell types such as neurons that are otherwise inaccessible. In the context of Alzheimer's disease (AD), iPSC-derived neural cultures offer a unique opportunity to investigate pathological mechanisms in a controlled environment, overcoming limitations of animal models. Central to AD pathogenesis is the amyloid cascade hypothesis, which is based on the concept that accumulation and aggregation of the toxic oligomeric species, initiates a cascade of events leading to synaptic dysfunction, neuronal loss, and cognitive decline. It is known that application of the Aβ oligomers to neurons reproduces key features of synaptic impairment, preceding overt neuronal death. In this study, we proposed an optimized protocol employing iPSC-derived neurons exposed to Aβ1-42 peptide. This approach provides a clear and reliable method to evaluate neurotoxic effects of Aβ peptide on neuronal morphology and viability. Indeed, on the one hand neuronal morphology, assessed through immunofluorescence using specific neuronal markers, allows precise monitoring of neurite length and synaptic connectivity, crucial parameters to evaluate neuronal health. On the other hand, cytotoxicity is directly quantified using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, which confirm Aβ-induced neuronal injury. Notably, this combined approach provides novel insights into early Aβ-driven neurodegenerative processes and offers a platform to identify therapeutic strategies targeting the initial phases of AD pathology.