Characteristics and Transcriptomic Analysis of Cholinergic Neurons Derived from Induced Pluripotent Stem Cells with APP Mutation in Alzheimer’s Disease

Background: The cholinergic hypothesis is one of the main theories that describe the pathogenesis of Alzheimer’s disease (AD). Cholinergic neurons degenerate early and are severely damaged in AD. Despite extensive research, the causes of cholinergic neuron damage and the underlying molecular changes remain unclear. Objective: This study aimed to explore the characteristics and transcriptomic changes in cholinergic neurons derived from human induced pluripotent stem cells (iPSCs) with APP mutation. Methods: Peripheral blood mononuclear cells from patients with AD and healthy individuals were reprogrammed into iPSCs. The iPSCs were differentiated into cholinergic neurons. Cholinergic neurons were stained, neurotoxically tested, and electrophysiologically and transcriptomically analyzed. Results: The iPSCs-derived cholinergic neurons from a patient with AD carrying a mutation in APP displayed enhanced susceptibility to Aβ1-42-induced neurotoxicity, characterized by severe neurotoxic effects, such as cell body coagulation and neurite fragmentation. Cholinergic neurons exhibited electrophysiological impairments and neuronal death after 21 days of culture in the AD group. Transcriptome analysis disclosed 883 differentially expressed genes (DEGs, 420 upregulated and 463 downregulated) participating in several signaling pathways implicated in AD pathogenesis. To assess the reliability of RNA sequencing, the expression of 16 target DEGs was validated using qPCR. Finally, the expression of the 8 core genes in different cell types of brain was analyzed by the AlzData database. Conclusions: In this study, iPSCs-derived cholinergic neurons from AD patients with APP mutations exhibit characteristics reminiscent of neurodegenerative disease. Transcriptome analysis revealed the corresponding DEGs and pathways, providing potential biomarkers and therapeutic targets for advancing AD research.